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QUALITY ASSURANCE PROJECT PLAN
LONG ISLAND SOUND AMBIENT WATER QUALITY MONITORING PROGRAM
2017
STATE OF CONNECTICUT DEPARTMENT OF ENERGY & ENVIRONMENTAL PROTECTION BUREAU OF WATER PROTECTION AND LAND REUSE (formerly the Department of Environmental Protection/Bureau of Water Management) 79 Elm Street Hartford, Connecticut 06106-5127
Rev. 05092017
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A2 TABLE OF CONTENTS
List of Figures List of Tables A Project Management 3 Distribution List ………………….…………………………………… 1 4 Project/Task Organization ……………………………….…………… 2 5 Problem Definition/Background …………………………………...… 4 6 Project/Task Description …………………………………………….. 5 7 Quality Objectives and Criteria for Measurement Data ….………….. 9 8 Special Training/Certification………………………………..………. 15 9 Documents and Records……………………………………….…….. 15 B Data Generation and Acquisition 1 Sampling Process (Experimental) Design…………………………… 16 2 Sampling Methods……………………………………………….….. 18 3 Sample Handling and Custody……………………………...……….. 21 4 Analytical Methods…………………………………………..……… 23 5 Quality Control………………………………………………………. 25 6 Equipment Testing, Inspection and Maintenance…………….……… 27 7 Instrument/Equipment Calibration and Frequency………………..…. 28 8 Inspection of Supplies…………………………………………..……. 28 9 Nondirect Measurements…………………………………..………… 28 10 Data Management…………………………………………………… 29 C Assessment and Oversight 1 Assessments and Response Actions………………………………….. 30 2 Reports to Management………………………………………………. 30 D Date Validation and Usability 1 Data Review, Validation and Verification Requirements……………. 30 2 Validation and Verification Methods………………………………… 31 3 Reconciliation with Data Quality Objectives………………………… 32
APPENDICES A. CTDEEP Long Island Sound Water Quality Monitoring Program Standard Operating Procedures Manuals B. Nutrient Analytical Services Laboratory Standard Operating Procedures manuals ------Version 1.0 5/09/2017 RFA17069 List of Figures/Tables
List of Figures
A4-1. Project Organization A6-1. CTDEEP Long Island Sound Ambient Water Quality Monitoring Program station map.
List of Tables
A6-1. Station information for all fixed stations sampled.
A7-1. Measurement quality objectives and quality assurance sample information for field water column observations.
A7-2. Measurement quality objectives and quality assurance sample information for laboratory analyses.
A7-3. Manufacturer’s equipment specifications.
B2-1. Summary of field methods for Long Island Sound Ambient Water Quality Monitoring Program basic water quality variables.
B3-1. Summary of sample containers, preservation, and holding times for the Long Island Sound Ambient Water Quality Monitoring Program water quality indicators sample analyses.
B4-1. Summary of field and analytical methods for Long Island Sound Ambient Water Quality Monitoring Program water quality indicators sample analyses.
B5-1. Measurement quality objectives and quality assurance sample information for field water column observations.
B5-2. Measurement quality objectives and quality assurance sample information for laboratory analyses. Version 1.0 5/09/2017 RFA17069 Section A3
A3 Distribution List
Leah O’Neill Nora Conlon U.S. EPA New England USEPA NERL Suite 100 (OEP06-1) 11 Technology Drive 5 Post Office Square North Chelmsford, MA 01863 Boston, MA 02109-3912 (617) 918-8369 (617) 918-1633 FAX (617) 918-8397 [email protected] [email protected]
Chris Bellucci Matthew Lyman CTDEEP BWPLR CTDEEP WPLR 79 Elm Street 79 Elm Street Hartford, CT 06106-5127 Hartford, CT 06106-5127 (860) 424-3715 (860) 424-3158 [email protected] [email protected]
Christine Olsen Katie O’Brien-Clayton CTDEEP BWPLR CTDEEP WPLR 79 Elm Street 79 Elm Street Hartford, CT 06106-5127 Hartford, CT 06106-5127 (860) 424-3727 (860) 424-3176 [email protected] [email protected]
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A4 Project Organization
Refer to Figure A4-1, Project Organization. Leah O’Neill, EPA New England, will have administrative oversight of the project. The project is planned, organized, and implemented by the Connecticut Department of Energy & Environmental Protection, Bureau of Water Protection and Land Reuse, Water Planning & Management Division. The Supervisor of the Division’s Long Island Sound Monitoring group (currently Christopher Bellucci) will be responsible for overall program supervision. Current staff Christine Olsen, Environmental Analyst 3 in the Long Island Sound Monitoring group, will be responsible for QA review, conducting appropriate reviews of laboratory data, laboratory QC, ensuring that QA and reporting requirements are met, review and verification of data, including quality assurance data, for completeness and to document any obvious or suspected problems; accuracy and completeness of the Program database; and coordination with laboratory QA manager to rectify any obvious or suspected problems. Current staff Matthew Lyman, Environmental Analyst 3 in the Long Island Sound Monitoring group, will be responsible for oversight of all field operations and data management of the monitoring program, including: scheduling and logistics; hiring and training seasonal assistants; overseeing and directing activities of field/office program staff; ensuring that field staff have reviewed Program QAPP and SOPs, received appropriate training in field and data entry/processing methods, and have shown competence in the performance of assigned duties; field data and sample chain-of-custody documentation; and database development and maintenance. Current staff Katie O’Brien-Clayton, Environmental Analyst 2 in the Long Island Sound Monitoring group, will be responsible for documentation, records, and reporting and assisting with field operations logistics including scheduling and conducting field surveys, hiring and training of seasonal field staff, and data entry and processing.
The University of Connecticut Center for Environmental Science and Engineering (CESE), Analytical Services/Nutrients Lab, or other capable laboratory will provide nutrient analytical services. The Laboratory’s Director and/or Quality Assurance Officer will direct and ensure quality for the laboratory procedures. The Laboratory’s Nutrient Lab Chemist or Technician will be responsible for nutrient lab sample handling and custody procedures and sample analyses as well as the provision of required supplies to the field crew.
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EPA Project Officer EPA QA Officer (Leah O’Neill) (Nora Conlon)
CTDEEP Long Island Sound Monitoring Supervisor (Christopher Bellucci)
CTDEEP Field CTDEEP Project QA Manager Operations/Database Manager (Christine Olsen) (Matthew Lyman)
CTDEEP Program Field Staff (Katie O’Brien- Laboratory Subcontractor Clayton; seasonal (e.g. CBL, CESE) field staff) Lab Director/QA Manager
Laboratory Subcontractor Nutrient Lab Chemist or Technician
Figure A4-1. Project Organization.
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A5 PROBLEM DEFINITION/BACKGROUND
A5.1 Purpose/Background
To complement the development of a coupled hydrodynamic-water quality model being prepared as part of the Long Island Sound Estuarine Study (LISS) by the National Oceanic and Atmospheric Administration (NOAA) and Hydroqual, Inc., a series of comprehensive field surveys were conducted during 1988, 1989 and 1990. These surveys, designed to provide water column data essential to initialize, calibrate, and verify the numerical models, were conducted by the Marine Sciences Institute (MSI) of the University of Connecticut, the Marine Sciences Research Center (MSRC) of the State University of New York at Stony Brook, and the New York City Department of Environmental Protection (NYCDEP). The range of effort included in this work served to significantly extend the database developed over the preceding two years of the program, detailing water temperature- salinity structure throughout the Sound and established the first comprehensive dataset providing reasonably synoptic observations of flow and concurrent water quality characteristics on a Sound-wide basis. Such a data set was considered essential to modeling efforts and thus to management strategy development and implementation.
In an effort to provide continuity to the dataset developed during the years since the LISS Program was initiated, and to provide continuity from the research/evaluation phase of the program into the implementation phase, the CT DEEP (formerly DEP) initiated a Long Island Sound Ambient Water Quality Monitoring Program in January of 1991. This Program has continued, with EPA support, and has been expanded from 7 stations sampled monthly (January 1991 through December 1994) to 17 stations sampled monthly (April 2002 to present), with a period during which 18 stations were sampled monthly (January 1995 to March 2002). A Summer Hypoxia Survey, focused on observations of the area and duration of hypoxia in the bottom waters of the Sound each summer, samples up to thirty additional stations on a bimonthly basis through the summer months (mid-June through mid-September). These surveys monitor offshore waters of Long Island Sound only. Nearshore waters of less than 5-meter depth, and embayments are not part of the monitoring covered by this QAPP.
The LISS identified low dissolved oxygen (DO) in the bottom waters of the Sound as the highest priority issue and implemented a process to reduce nutrient loads to the Sound in an effort to improve bottom water DO conditions over time. The data to be provided by these surveys is considered essential to the continued evaluation of model predictions, and to monitor the effectiveness of management actions being taken to reduce nitrogen sources to the Sound.
The goals of the Department’s Long Island Sound Ambient Water Quality Monitoring Program are:
To monitor water quality parameters year round on a monthly schedule at stations throughout Long Island Sound
To monitor the temporal and spatial extent of summertime hypoxia through Sound- wide sampling every other week from late June through mid-September
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To maintain a long-term database of the information collected
The objectives of the Program are:
To review the data periodically, in combination with available historical data, for trends
To assess the long-term results of specific management actions such as the “no-net increase” nutrient (nitrogen) policy adopted in 1990 and the nutrient reduction strategy implemented in 1994
To provide state and federal managers and policy-makers with information on existing conditions and trends that can be used in the development, implementation and assessment of strategies to control and improve water quality in the Sound
To make the data available for related efforts such as water quality assessments, research, TMDL development and evaluation, and water quality model development and calibration
To make data available to other interested individuals/groups
A6 Project Description and Schedule
Schedule of Surveys
The Monthly Field Survey involves sampling at 17 fixed stations (Figure A6-1and Table A6-1), each station sampled once per month, generally during the first week of the month, and year-round.
The Summer Hypoxia Survey typically involves sampling at a minimum of 20 stations, up to a maximum of 42 from 47 available (Figure and Table A6-1). Sampling is conducted every other week beginning the third week of June through the first week of September, for a total of six unique surveys. This survey is combined with the Monthly survey during the July, August, and September Monthly surveys, with the fixed Monthly stations contributing to the total number of stations sampled for purposes of assessing hypoxic conditions. Hypoxia is most prevalent in the western-to- central sound (the Narrows, Western Basin and the western half of the Central Basin), so stations in these areas will tend to be sampled with higher frequency. Dissolved oxygen observations of less than 3.5 mg/L during the early September (Monthly) survey will dictate the need for a seventh survey to be conducted on or about the third week of September. The first (mid-late June) and last (mid-late September, when conducted) Hypoxia surveys of each summer season may involve sampling at fewer than 20 stations since these surveys are often conducted when hypoxia is absent or involves only a relatively small spatial area, so that an assessment of the area affected can be accomplished with fewer samples.
Calendar, weather, vessel/crew availability, and competing project constraints are expected to
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N New New London Haven
36 34 29 32 K2 M3 N3 26 rk Bridgeport 30 Yo J2 ew H2 N t 21 ticu 27 nec on 23 I2 C Norwalk 16 18 12 H4 J4 Stamford 09 F2 22 28 13 19 08 E1 F3 H6 05 31 33 Mattituck D3 14 20 03 C2 25 01 06 C1 07 10 02 04 Port Jefferson B3 15 A4 Smithtown Oyster Bay
A2
10 0 10 20 30 40 Kilometers
Figure A6-1. CTDEP Long Island Sound Ambient Water Quality Monitoring Program station map. Seventeen underlined stations serve as monthly water quality monitoring sites. Thirty additional sites are sampled, at varying frequencies, during summer hypoxia surveys. See Table A6-1 for station information.
occasionally affect this schedule, resulting in samples taken earlier or later, or occasional missed samples. Parameters
Parameters and methods utilized during the previous twenty-six years of the Long Island Sound Water Quality Monitoring Program will be continued (Table A7-1 and Table A7-2). Field sampling will be conducted by personnel from CTDEEP. Filtration of samples for nutrient analyses will be conducted in the field and all filters and filtrate samples prepared will be delivered to an appropriate laboratory, with proven capability with regard to low-level estuarine nutrient analysis. Laboratories that have provided analytical services in the past, and are most likely to be used going forward include the Nutrient Analytical Services Laboratory of the University of Maryland, Center for Environmental Science, Chesapeake Biological Laboratory (NASL-CBL); and the University of Connecticut’s Center for Environmental Sciences and Engineering (UCONN-CESE). Field methods, apparatus, sample types and sample handling information are contained in Tables B2-1, B3-1, and B4-1.
Data Availability
All field data, including the CTD profile data will be processed within one month of recovery, and
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Summary reports will be prepared following each Summer Hypoxia survey and submitted to EPA and other interested parties via email, typically within one week of the survey completion. Annual Hypoxia Survey reports, including a summary of the year’s hypoxic event and comparisons to previous years will be submitted to EPA within six months of the Survey end. Progress reports of the Monthly Survey can be prepared for submission to EPA upon request of the Project Officer.
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Table A6-1. Station information. See Figure A6-1.
Station Station Depth Latitude Longitude General Sampling Notes Name (meters) Schedule Record Narrows A4 32.6 40 52.35N 73 44.05W Year round 8/94 - present B3 18.0 40 55.10N 73 38.57W Year round 2/91 - present 01 14.8 40 57.80N 73 37.42W Summer 6/94 - present 02 15.8 40 56.08N 73 36.04W Summer 6/94 - present C1 19.8 40 57.35N 73 34.82W Year round 12/94 - present 03 24.1 40 58.76N 73 33.64W Summer 6/94 - present 04 12.3 40 56.27N 73 31.16W Summer 6/94 - present C2 32.4 40 59.06N 73 30.13W Year round 12/94 - present 05 13.0 41 00.56N 73 30.82W Summer 6/94 - present 06 18.2 40 57.67N 73 28.60W Summer 6/94 - present 07 12.7 40 57.02N 73 25.52W Summer 6/94 - present 08 12.9 41 02.45N 73 25.08W Summer 6/94 - present D3 40.9 40 59.63N 73 24.68W Year round 2/91 - present Western Basin 09 9.1 41 04.25N 73 20.17W Year round 6/94 - present 10 17.3 40 57.10N 73 19.95W Summer 6/94 - present E1 38.1 41 01.16N 73 17.48W Year round 12/94 - present 12 10.5 41 06.52N 73 15.18W Summer 6/94 - present 13 22.3 41 03.50N 73 14.06W Summer 6/94 - present 14 25.4 40 59.49N 73 13.13W Summer 6/94 - present 15 15.3 40 55.88N 73 13.27W Year round 6/94 - present 16 8.9 41 07.22N 73 09.75W Summer 6/94 - present F2 19.7 41 04.82N 73 09.92W Year round 12/94 - present F3 40.9 41 01.07N 73 08.67W Year round 1/91 - present Central Basin 18 12.6 41 07.34N 73 05.40W Summer 6/94 - present 19 25.5 41 03.32N 73 04.85W Summer 6/94 - present 20 22.5 40 59.64N 73 02.54W Summer 6/94 - present 21 14.3 41 09.84N 73 00.89W Summer 6/94 - present 22 26.9 41 04.94N 73 01.37W Summer 6/94 - present H2 13.9 41 10.68N 72 57.63W Year round 6/94 - present 23 19.0 41 08.41N 72 56.93W Summer 6/94 - present H4 23.7 41 06.10N 72 56.04W Year round 6/94 - present H6 41.4 41 01.56N 72 54.81W Year round 1/91 - present 25 10.7 40 58.86N 72 55.09W Summer 6/94 - present 26 11.2 41 12.55N 72 54.51W Summer 6/94 - present 27 20.2 41 09.52N 72 50.97W Summer 6/94 - present 28 30.1 41 04.69N 72 50.01W Summer 6/94 - present 29 9.4 41 13.89N 72 49.78W Summer 6/94 - present 30 15.3 41 11.78N 72 46.52W Summer 6/94 - present 31 25.8 41 00.25N 72 46.10W Summer 6/94 - present sampled infrequently 32 10.7 41 14.49N 72 39.94W Summer 7/94 - present sampled infrequently I2 27.3 41 08.25N 72 39.30W Year round 1/91 - present Eastern Basin 33 20.2 41 00.23N 72 39.07W Summer 6/94 - present sampled infrequently 34 16.7 41 14.76N 72 28.10W Summer 6/94 - present sampled infrequently J2 21.8 41 10.92N 72 27.46W Year round 6/94 - present J4 18.5 41 05.85N 72 27.00W Summer 6/98 - present sampled infrequently 36 6.6 41 16.23N 72 16.53W Summer 7/94 - present sampled infrequently K2 37.7 41 14.06N 72 15.95W Year round 7/94 - present M3 72.6 41 14.23N 72 03.20W Year round 1/91 - present
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A7 Quality Objectives and Criteria
The primary focus of the CTDEEP’s Long Island Sound Ambient Water Quality Monitoring Program is to monitor and document basic water column characteristics (temperature, salinity, density, light, chlorophyll, suspended solids) and nutrient concentrations to detect changes over time and be able to estimate the rate of any such changes. The Program also serves as a long-term, consistent data source to support Long Island Sound related research. Because the Program’s focus is measurements, goals for data quality focus on individual measurements. With regard to long-term trend analyses, the data quality objective is that for each variable of interest (ambient nitrogen, phosphorus, chlorophyll a, dissolved oxygen, etc.) an existing trend can be detected with 95% confidence, and the rate of change estimated within 20%.
Measurement Quality Objectives
One measure of data quality is completeness. With regard to analytical laboratory measurements the goal for record completeness is 100%. Twenty-six years of sampling on this monitoring program (January 1991 through December 2016) has produced a dataset with a 96% completeness record with regard to expected station visits. During the most recent five-year period, 2012-2016, 100% of expected stations visits were completed. If missed station visits are not considered, the completeness of the analytical data through November 2016 (for all completed station visits) is 99%. For some years, 100% completeness in both areas was achieved. Completeness is affected by cancelled cruises and missed stations during a cruise (i.e. expected samples are never collected), and by field or laboratory accidents or malfunctions that render collected samples insufficient for any or all analyses, or that render analytical results unattainable or unreliable. Missed station visits are generally due to weather related conditions and lack of vessel or crew availability for rescheduling, or other vessel issues, including availability or where the use of an alternate/backup vessel meant limitations to sampling.
With regard to Water column profile data obtained with a Conductivity-Temperature-Depth (CTD) profiler, the achievable level of data completeness is somewhat less, but still very high overall. Over the first nineteen years of data (through May 2010), the total number of CTD-related records was over 680,000 (including all survey types) [511,000 from monthly WQ surveys only] compared with 103,800 [101,900 from monthly WQ surveys only] nutrient/analytical records. Each CTD record holds data averaged from a 0.2 meter slice of the water column. A single profile from a 20 meter deep station, for example, would be expected to have approximately 100 records. Overall, nineteen years of sampling produced a CTD dataset better than 96% complete, based on existing profiles. In addition, there are profiles that were never obtained because of missed station visits, inoperable or malfunctioning equipment, or operator error. Because the dissolved oxygen sensor is a separate component and is affected by clogged plumbing and membrane problems, dissolved oxygen data may be lost without the concurrent loss of pressure, temperature and salinity data within that depth record. In fact, a review of the CTD data (nineteen years, through May 2010) shows dissolved oxygen data is incomplete approximately 5% of the time, compared to available CTD pressure data. Comparatively, CTD-measured temperature is incomplete 2% of the time, and conductivity/salinity 3% of the time.
A second measure of data quality is representativeness. Sampling occurs monthly, year-round at
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fixed station locations. These locations were chosen based on historical sample locations and data, basin morphology of the Sound, and depth strata to be representative of ambient conditions Sound- wide. Sample collection and handling procedures are important to maintain representativeness, and they must be followed consistently. Samples stored temporarily in Niskin sample collection bottles must be well-mixed before any subsample is drawn. Samples must be stored according to SOP specifications to maintain sample integrity until analysis.
A third measure of data quality is comparability. Program sampling procedures are based on previous data collection efforts of the Long Island Sound Study and were designed in concert with participants from this previous monitoring, water quality model development team, and expert participants in the development of the LISS Monitoring Plan to support the CCMP. Most sampling and analytical procedures remain the same as those implemented over the previous nineteen years of this monitoring program. Consistent field and laboratory procedures, well- documented by the appropriate SOPs, help ensure consistent and reproducible data. Changes in methods will be accompanied by a period of split samples, allowing for adequate comparison between the results of the new method and the old. Beginning in 2010 the analytical laboratory being used for sample analysis has been required to participate in a multi-lab comparison program that provides data specifically to assess the laboratory’s ability to produce data comparable to several other laboratories located in the Northeast and Mid-Atlantic regions of the United States (see further discussion below).
Procedures for Assessing Accuracy and Precision: This QAPP is designed to ensure that accurate and precise data are being generated. Quality control (QC) measures include those actions which are taken in the laboratory to verify that the measurement system is in control (e.g. instrument calibration; the analysis of reference standards; the analysis of matrix spikes, replicates, and blanks). The QA program is designed to manage sample handling, documentation and custody; proper data generation; and quality control actions. The QA program primarily tracks and monitors the fate of a sample from collection to data submission allowing the Project Manager and technical staff to assure proper sample analysis through appropriate methods, and that the necessary QC measures have been taken to ensure that representative data of definable quality have been produced.
Analytical laboratory procedures, including the key elements of laboratory quality control are documented in laboratory-specific documentation (Appendix B). A number of routine quality control (QC) checks are analyzed with each batch of samples, including continuing calibration verification, calibration blanks, laboratory duplicates, and spike sample analyses. The goal for each sample batch is to run each QC check on 10% of samples. Field blanks (prepared randomly once each cruise day to evaluate contamination potential) and field duplicates (replicates taken in rapid succession to estimate field precision) are also provided to the laboratory, at a rate of at least one per ten samples (10%).
Determination of accuracy will be accomplished by evaluating a continuing series of spiked samples. Percent recovery in the range of 85 to 115% is considered to be acceptable providing all other QC conditions are within acceptable limits. Accuracy of analysis will also be assessed by analyzing standard reference materials obtained commercially. The Continuing Calibration Verification (CCV), by analysis of standard reference materials (including, when available, EPA
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Quality Control Solutions) must fall within the control limits of 85-115% of the true value for instrument performance to be deemed acceptable.
Beginning in 2010, the laboratory providing nutrient analytical services was and will continue to be required to participate in the Chesapeake Bay Blind Audit Program. The current program provides estuarine nutrient samples to laboratories twice per year for interlab comparisons of analytical results. Samples include both particulate and dissolved (high and low concentrations) samples for all of the standard analytes (carbon, nitrogen, phosphorus), plus chlorophyll. Typically twelve, or more, laboratories participate. The comparison data is valuable as an ongoing evaluation of laboratory accuracy in methods and results. The CTDEEP made participation in this semi-annual audit a condition of the scope-of-work agreement with UCONN-CESE, and will continue to require participation by any primary lab services provider as long as the program is available. The audit program is administered by NASL-CBL of the University of Maryland, which is also a participating laboratory.
Determination of precision will be accomplished by evaluating a continuing series of replicated samples. The Relative Percent Difference (RPD) is used to evaluate the long term precision of the method for each parameter. A control limit of +/- 15% RPD shall be used to define acceptable precision.
Accuracy and precision goals for measured parameters are provided in Tables A7-1 and A7-2, along with quality assurance sample types. Accuracy and precision goals are based on instrument manufacturer or analytical laboratory specifications, or historical data or experience. Most variables have one or more QA/QC samples associated with them.
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Table A7-1. Measurement quality objectives and quality assurance sample information for field water column observations. Variable Precision QA Sample Type Frequency Data Generated Goal of QA
Performance verification CTD response vs. Depth ± 0.5 m at certified calibration Annually calibration standards; facility annual drift Difference between CTD QC check against vessel’s Depth ± 0.5 m Every cast station depth and on- depth finder board depth finder Performance verification CTD response vs. Temperature ± 0.5 oC at certified calibration Annually calibration standards; facility annual drift QC check against CTD temperature vs. Temperature ± 0.5 oC secondary thermistor in Every cast oxygen sensor temp DO sensor module Performance verification CTD response vs. Salinity ± 0.5 psu at certified calibration Annually calibration standards; facility annual drift
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Table A7-2. Measurement quality objectives and quality assurance sample information for laboratory analyses. Variable Accuracy Precision QA Sample Type Frequency Data Generated Goal Goal of QA
Analytical Laboratory Measurements Ammonia Standards, spikes, lab and Per batch; Relative accuracy and 85-115% 15% field duplicates; one cruise precision (NH3) semiannual audit Standards, spikes, lab and field duplicates; QC Relative accuracy and Nitrate + Nitrite check against Day-0 Per batch; precision; secondary NOx - 85-115% 15% (NO3 +NO2) whole water BOD sample one cruise measurement on fresh at up to 10 stations; sample semiannual audit Total Dissolved Standards, spikes, lab and Per batch; Relative accuracy and Nitrogen (TDN) 85-115% 15% field duplicates; one cruise precision semiannual audit Particulate Field blanks and field Per batch; Precision; estimate of Nitrogen (PN) 85-115% 15% duplicates; semiannual one cruise field contamination audit Orthophosphate Standards, spikes, lab and Per batch; Relative accuracy and 3- (PO4 ) or 85-115% 15% field duplicates; one cruise precision (DIP) semiannual audit Total Dissolved Standards, spikes, lab and Per batch; Relative accuracy and Phosphorus 85-115% 15% field duplicates; one cruise precision (TDP) semiannual audit Particulate Standards, spikes, field Relative accuracy and blanks, lab and field Per batch; precision; estimate of Phosphorus 85-115% 15% (PP) duplicates; semiannual one cruise field contamination audit Dissolved Standards, spikes, lab and Per batch; Relative accuracy and Organic. 85-115% 15% field duplicates; one cruise precision Carbon (DOC) semiannual audit Particulate Field blanks and field Per batch; Precision; estimate of Carbon (PC) 85-115% 15% duplicates; semiannual one cruise field contamination audit Dissolved Silica Standards, spikes, lab and Per batch; Relative accuracy and 85-115% 15% (SiO2) field duplicates one cruise precision Standards, spikes, field Relative accuracy and Biogenic Silica Per batch; 85-115% 15% blanks, lab and field precision; estimate of (BioSi) one cruise duplicates field contamination Standards, spikes, field Relative accuracy and Chlorophyll a Per batch; 85-115% 15% blanks, field duplicates; precision; estimate of (Chl a) one cruise semiannual audit field contamination Total Standards, field blanks Per batch; Precision; estimate of Suspended NA 15% and duplicates; replicates Solids (TSS) averaged one cruise field contamination Biological Per batch; Oxygen NA 15% Field duplicate Precision Demand (BOD) one cruise
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Table A7-3. Manufacturer’s equipment specifications.
SPECIFICATIONS: SBE-19 SeaCat Profiler (from: SeaBird Electronics, Inc.)
Measurement Range: Temperature -5 to +35 ºC Conductivity 0 to 7 S/m (0 to 70 mmho/cm) Pressure Strain Gauge Sensor 150 psia
Accuracy: Temperature 0.01 ºC/6 months Conductivity 0.001 S/m/month Pressure Strain Gauge Sensor 0.25% of full scale range (150 psia)
Resolution: Temperature 0.001 ºC Conductivity 0.0001 S/m Pressure Strain Gauge Sensor 0.015% of full scale range (150 psia)
Sensor Calibration: Temperature -1 to +31 ºC Conductivity 0 to 7 S/m. Physical calibration over the range 1.4 - 6 S/m. Pressure 0 to full scale in 20% steps
SPECIFICATIONS: SBE-23 Dissolved Oxygen Sensor (from: SeaBird Electronics, Inc.) Type: Modified YSI Model 5739 oxygen probe Temp. Range: -5 to +45 ºC Thermistor Accuracy: 0.2 ºC Response Time: two seconds
SPECIFICATIONS: WETStar Fluorometer (from: WetLabs, Inc.) Rated Depth: 600 meters Response Time: 0.17 sec Optical Sensitivity: 0.03 µg/l Dynamic Range: 0.03–75 µg/l
SPECIFICATIONS: LI-193SA Spherical Quantum Sensor (from: LI-COR, Inc.) Rated Depth: 350 meters (500psi) Detector Type: Silicon photovoltaic Sensitivity: 7µA per 1000µmols/sec/m2 Stability: < 2% change over one year Angular Response: < 4% error up to 90º from normal axis (top half of sphere) Abs. Calibration: Within 5% in air Response Time: 10 µS
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A8 Special Training Requirements/Certification
Any CTDEEP staff member who participates in field operations will be trained, as needed, in each field function they will be required to perform (equipment handling, filtering tasks, titrations, etc.) and their performance closely observed. Training will be conducted by the technical project supervisor, the field operations manager, or their designee. All procedures for equipment handling, sample collections, and sample handling, including procedures for Winkler titrations and filtering are documented in the Long Island Sound Ambient Water Quality Monitoring Program Water Quality and Hydrographic Surveys Standard Operating Procedures Manual, 2017 (SOP) (Appendix A). All personnel that will assist with this monitoring will be required to review the SOP prior to participating in a survey, and all personnel will be supervised, at a minimum, the first two times any new task is performed. Staff will not be allowed to proceed unsupervised unless and until they have shown proficiency in each particular field activity. Proficiency will be based on the individual’s ability to progress through each documented step of a procedure with no reminders and no errors in method. Of particular importance in field sample handling is avoiding sample contamination, maintaining well-mixed samples, accurate volume measurements, and accurate data recording. At least one permanent staff of the Program will be present on the vessel during field operations, so that new staff performance will continue to be evaluated. At least two fully trained staff will be present whenever staff-in-training are onboard the research vessel.
A9 Documentation and Records
Field Activities Field crews will record appropriate data on hardcopy field datasheets (Appendix A). All of the information contained on the Field Datasheet will be entered into the Program’s database with the use of an electronic Field Datasheet Form, designed to resemble the hardcopy form. All field data will be entered into the electronic database form within one week of the end of each survey. This database form is designed with protections against incorrect entries (e.g. it will not allow duplicate station entries) and all field datasheets entries will be performed twice. A program to compare the two unique entries will then be used to find any typographic errors. Once any errors are corrected, the field data will be uploaded to the appropriate database table. This dual entry virtually eliminates the chances of typographical errors since any item that does not match between the two entries will be verified using the field datasheet. Limits will be placed on some of the entry fields as well (e.g. if air temperature entry falls outside the range [–10 - +35oC] text will appear: [temperature is not within reasonable range]). All latitude/longitude coordinates entered will be mapped to confirm they are within the expected area. Outliers are generally easy to pick out, for example when a 73o longitude is recorded instead of a 72, or vice versa.
The CTD profiler will generally be operated in real-time, allowing real-time capture of the data file in electronic form. When the CTD is not being operated in real-time, data files will be uploaded to the computer as soon as possible in the field to confirm that a complete file was obtained. CTD files are named with the station name and date for easy identification later. CTD data files are reviewed and processed prior to upload to the Access database. Original, raw and processed CTD files are maintained for archival once the final processed files are uploaded to the Program database.
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A Data File Processing Record (Appendix A) is used to document the status of processing for each CTD file from any particular cruise. A Data Processing Cover Sheet (Appendix A) is used to document the status of all field data entry and CTD file processing for a particular cruise. These two documents are filed with the original Field Datasheets, by cruise and year. Current procedure calls for maintenance of these paper files in full. Field Datasheets are also scanned and maintained in electronic format.
The Program database links all station/date specific data. All CTD profile data records are uniquely identified by the Station Name, Cruise Name, and depthx10. All nutrient data are uniquely identified by the Station Name, Cruise Name, DepthCode (S, B, etc), and parameter.
Sample Custody Procedures Sample labeling and custody procedures are discussed in Section B3, Sample Handling and Custody. Appropriate chain of custody paperwork will accompany all samples from collection to the analytical facility (Appendix A). Unique sample codes, consisting of the date, station name and sample depth code, will be assigned at the time of collection and recorded on the custody forms as well as on the field datasheet and on the sample container. A second unique sample number will be assigned at the laboratory and recorded on the custody forms, a copy of which will be retained by Program staff.
The analytical laboratory will provide data in agreed-upon electronic form. Electronic results files allow for direct transfer into the Program’s database, eliminating the need for any manual data entry. The electronic report package will include a cover letter from the lab that notes any problems (e.g. lab accidents, QA standards or holding times exceeded, etc) or unusual results and what, if anything, was done to confirm such values (e.g. if a sample was re-analyzed, etc.). The report package from the laboratory will also include the QA/QC data and copies of chain-of–custody forms that accompanied the samples. This report package should be submitted to the Program within 60 days of the receipt of all samples from a particular cruise. The laboratory will retain raw data files, including notebooks, calibration and calculation records. The Laboratory SOP (Appendix B) contains specific requirements for holding times and number and type of QC samples for each variable.
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Section B: Data Generation and Acquisition
B1 Sampling Process (Experimental) Design
The Long Island Sound Ambient Water Quality Monitoring Program (the “Program”) is an established year-round monitoring program made up of two distinct surveys. The Monthly Water Quality Monitoring Survey (the “Monthly Survey”), and the Summer Hypoxia Monitoring Survey (the “Hypoxia Survey”).
Both surveys will continue to monitor established fixed stations (Table A-1). Stations will be located with the use of a programmable GPS system. Actual latitude/longitude coordinates at the time of CTD deployment will be recorded on the field data sheet.
All measurements are considered critical to the goal of establishing a long-term dataset capable of revealing potential influences and trends of water quality in Long Island Sound.
Instantaneous water column profiles will be obtained at every station visit with the use of a Sea- Bird SeaCat Model SBE-19 or similar multi-parameter water quality monitoring instrument. These profiles will provide measurements of depth, water temperature, conductivity/ salinity, dissolved oxygen concentration, pH, light attenuation by PAR (quantum) sensor, and chlorophyll. Surface water clarity will be evaluated with a 20 cm Secchi Disk.
Monthly Survey The Monthly Survey will involve field sampling once per month at each of 17 fixed stations (Figure A-1 and Table A-1). Twelve stations are located along the deep-water axial transect of the Sound, beginning at Station A4 in the Western Narrows to the west, and extending eastward to Station M3 in the Race. Five stations are shallower, laterally placed stations in the Western and Central Basins.
In addition to the common field data/samples noted above, discreet surface and bottom water samples will be taken for dissolved and particulate nutrients (nitrogen, phosphorus, carbon and silica), chlorophyll a, suspended solids, and BOD analyses (Tables A7-1 and A7-2).
Hypoxia Survey The Hypoxia Survey will involve field sampling approximately every other week beginning in late June through early September, for a minimum of six sampling events. Three of these surveys overlap with, and will be performed in conjunction with Monthly Survey events. A seventh survey will be conducted in mid-September only if dissolved oxygen concentrations less than 3.5 mg/L are observed during the early September survey. Forty-eight fixed stations, concentrated in the Eastern Narrows and Western and Central Basins, and including the seventeen Monthly Survey sites will be sampled (Figure A6-1 and Table A6-1). These stations are concentrated in the western Sound, where low dissolved oxygen conditions have typically been most severe. An effort will be made to sample as many stations as possible given constraints of time and weather conditions. In some cases, when no hypoxia is observed in the western Sound or when the pattern of dissolved oxygen concentrations
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is evident from stations sampled (e.g., a large area of western or central LIS with dissolved oxygen concentrations above 5.0 mg/L), stations in the far eastern part of the Sound, where dissolved oxygen concentrations generally do not fall below 5.0 mg/L, may not be sampled.
B2 Sampling Methods
A full description of sampling methods is given in Appendix A.
Field Measurements Field measurements are to be obtained according to the procedures outlined in Long Island Sound Ambient Water Quality Monitoring Program, Water Quality and Hydrographic Surveys, Standard Operating Procedures Manual, 2017 (Program SOP) (Appendix A).
The field measurements to be made include the following: 1. A vertical water column profile of temperature, dissolved oxygen, conductivity, pH, chlorophyll (by fluorometer), and PAR. The vertical profile starts at the surface and is continuous to the bottom. The CTD descent rate will be maintained as close to 0.2 meter/second as possible and will be monitored in real-time via the use of an on-board computer. The instrument will be programmed to record measurements at a rate of 2 per second. While upcast data is not recommended for general use and evaluation because optimal sensor (particularly dissolved oxygen) performance is not obtained, the upcast data will provide a duplicate profile of temperature, salinity, and PAR. 2. Maximum visible Secchi disk depth.
Hydrographic Profile Water column profiles will be obtained at each station with the use of a SeaBird Seacat model SBE-19 profiling instrument (CTD), or similar multi-parameter water quality monitoring instrument. Details on operation, calibration, and maintenance of the CTD system can be found in the Program SOP (Appendix A).
Water quality variables to be measured include temperature, conductivity/salinity, dissolved oxygen, pH, photosynthetically-active radiation (PAR), and chlorophyll a, all as a function of depth. The CTD will generally be mounted on a General Oceanics Rosette Multibottle Array and deployed from the stern of the 50 ft Research Vessel John Dempsey with the use of a hydraulic net reel. When circumstances do not allow the use of the array, the CTD will be deployed in a cage from a starboard winch. Prior to conducting the downcast, the CTD will be allowed a minimum three-minute “soak”, fully submerged near the surface. This soak time allows the internal pump to turn on and allows all sensors to stabilize and come to equilibrium with water conditions. The CTD downcast will then be conducted at a target rate of 0.2 meter/second, non-stop until the array reaches the bottom.
Water Sample Collection Water samples will be collected with the use of 5-liter Niskin water sampling bottles. The sampling bottles will generally be mounted on the General Oceanics Rosette Multibottle Array that allows for remote actuation of the sampling bottles. Sample bottles will be filled during the upcast. When
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circumstances do not allow the use of the array, sampling bottles will be mounted on a wire controlled by a starboard winch, and triggered with messengers. Details on the handling and maintenance of the sampling bottles and the array, as well as details of sample handling can be found in the Program SOP (Appendix A).
Monthly Survey For the Monthly Survey, samples will be collected from two depths at each station for nutrient analyses. Bottom samples will be collected 3-5 meters above the sediment and surface samples will be collected two meters from the surface. Sampling bottles will be filled at each depth, consecutively, within seconds of each other, by remote actuation of sample bottles mounted on the array.
Sample processing Grab water samples collected with the Niskin bottles will be filtered (ideally on board the research vessel in the ship’s onboard laboratory) prior to delivery to the analytical lab for particulate carbon/particulate nitrogen (PC/PN), chlorophyll-a (Chl-a), total suspended solids (TSS), particulate phosphorus (PP), and biogenic silica BioSi. Filters will be stored in the onboard lab freezer until delivery to the lab at the end of the day.
Filtrate will be collected for dissolved fraction analyses of ammonium (NH4), nitrate+nitrite (NO3+NO2 or NOx), total dissolved nitrogen (TDN), dissolved inorganic phosphorus/orthophosphate (DIP or PO4=), total dissolved phosphorus (TDP), dissolved organic carbon (DOC), and dissolved silica (SiO2) analysis.
All containers, including filtering flasks, that will come into contact with filtrate will be sample rinsed at least three times. This filtrate will be put into sample-rinsed labeled poly bottles provided by the analytical laboratory, and chilled or frozen for preservation in the onboard freezer until sample delivery to the lab at the end of the day. Whole water samples for BOD analysis will be drawn directly from Niskin sample bottles into one-half gallon poly jugs provided by the laboratory and chilled.
Details of sample processing is contained in the Program SOP (Appendix A).
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Table B2-1. Summary of field methods for Long Island Sound Ambient Water Quality Monitoring Program basic water quality variables (see Program SOP, Appendix A).
VARIABLE FIELD METHOD APPARATUS UNITS
Water column profile SeaBird SBE-19 (CTD) or YSI Depth Meters EXO2
Water Temperature Water column profile SeaBird SBE-19 (CTD) or YSI oC EXO2
Conductivity/ Salinity Water column profile SeaBird SBE-19 (CTD) or YSI PSU EXO2
Li-Cor Model LI-193SA Spherical PAR Water column profile uE/m2/sec Quantum Sensor as module on CTD
WETLabs WETStar Fluorometer as Chlorophyll a Water column profile mg/L module on CTD or YSI EXO2
SBE-23 sensor with modified YSI Dissolved Oxygen Water column profile 5739 oxygen probe as module on mg/L CTD or YSI EXO2
Surface Water Clarity Secchi depth 20 cm Secchi disk Meters
pH Water column profile YSI EXO2 pH
All procedures for handling the CTD or alternate sensor/profiling unit(s), and Niskin bottles, and all procedures for Winkler titrations and filtering are documented in the Program SOP (Appendix A). All personnel that will assist with this monitoring will be required to review the SOP prior to participating in a survey, and all personnel will be supervised, at a minimum, the first two times any new task is performed. A copy of the SOP will always be present on the research vessel should a staff member need to refer to it. Sample processing and handling protocols related to the laboratory analyses for nutrients and chlorophyll a are specified by the analytical laboratory and included in the relevant laboratory guidance/SOP documentation (Appendix B). Operating procedures for blanks, spikes and replicates are also included in the laboratory SOPs.
The shipboard laboratory will provide freezer and chilled storage space, and the capability to filter small volume samples. Supply of small volume bottles and all necessary filters will be the responsibility of the analytical laboratory.
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B3 Sample Handling and Custody
Field Data Recording Field crews will record most of the raw field data on hardcopy datasheets (Appendix A). The CTD profiling instruments have internal electronic file storage, and these files, if not recovered directly to the onboard computer in real-time, will be downloaded following the cast. All field data that is not in electronic form will be transcribed into an electronic database format generally within one week of the survey end date. The Program database has a Field Data Sheet Entry Form (Appendix A), to be used for all data entry that closely matches the hardcopy forms. All data entry will be performed twice. The two comparable entry logs will then be run through an in-house macro that compares each datum. Any differences between the two entries will cause a review of the hardcopy Field Data Sheet to determine the correct datum. The Field Datasheet Table in the database will then be updated with the final corrected Entry Form.
Sample Identity Codes All station visits will be uniquely identified by the Station Name and the Cruise Name. In the Program database these two items are consistently used as primary keys; they are required and no matching combinations are allowed. All nutrient data will be further identified by the Depth Code (“S” for Surface, “B” for Bottom) and the Variable measured. Samples containers to be used to store and deliver samples to the nutrient analytical lab will be pre-labeled with Station Name, Depth Code, Cruise Name, and, where necessary, the variable/variables to be measured. Packages used to store and transport PC/PN and Chlorophyll-a filters, for example, are identical, so that these labels must specify the variable. The date the sample is taken will be added to the containers in the field.
Chain of Custody Forms Sample chain-of-custody (COC) forms will accompany each delivery of samples to the analytical laboratory. COC forms will generally be prepared ahead of time with Station Names and Depth Codes (e.g. B3S = Station B3 Surface water) based on the typical three or four-day station visit plan. The volume of sample filtered, where applicable, and the filter identification number for TSS samples will be recorded on the COC forms by the field crew. The laboratory will log in all samples when they take possession, assigning a unique laboratory ID number to each unique sample. Laboratory ID numbers will be recorded by the laboratory staff directly on the COC forms and a completed copy returned to Program staff.
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Table B3-1. General summary of sample containers, preservation, and holding times for the Long Island Sound Ambient Water Quality Monitoring Program water quality indicators sample analyses (see Program SOP, Appendix A, and Laboratory SOPs, Appendix B, attached). Sample container volume may vary as per laboratory.
SAMPLE PRESERVATION HOLDING VARIABLE SAMPLE CONTAINER TYPE METHOD TIME 250-ml poly bottle with lid Ammonia (NH3) Filtrate (single filtrate bottle used for six Sample frozen 14 days variables; or as per lab)
- Nitrate + Nitrite (NO3 ) + Filtrate 250-ml poly bottle with lid Sample frozen 28 days - (NO2 )
Total Dissolved Nitrogen Filtrate 250-ml poly bottle with lid Sample frozen 28 days (TDN) 25mm 0.7um aluminum foil packet; 2 Sample frozen 28 days Particulate Nitrogen (PN) GF/F filter duplicate filters per packet
3- Orthophosphate (PO4 )/ Dissolved Inorganic Filtrate 250-ml poly bottle with lid Sample frozen 48 hours Phosphorus (DIP)
Total Dissolved Filtrate 250-ml poly bottle with lid Sample frozen 28 days Phosphorus (TDP)
47mm 0.7um aluminum foil packet; 2 Particulate Phosphorus Sample frozen 28 days (PP) GF/F filter duplicate filters per packet
Dissolved Organic Carbon Filtrate 250-ml poly bottle with lid Sample frozen 28 days (DOC) 25mm 0.7um aluminum foil packet; 2 Sample frozen 28 days Particulate Carbon (PC) GF/F filter duplicate filters per packet
Dissolved Silica (SiO2) Filtrate 125-ml poly bottle with lid Sample chilled/frozen 28 days 47mm 0.4um 50-ml poly centrifuge tube Particulate (Biogenic) polycarbonate Sample frozen 28 days with lid Silica (BioSi) filter 25mm 0.7um aluminum foil packet; 2 Sample frozen 30 days Chlorophyll a (Chl a) GF/F filter duplicate filters per packet
47mm 0.7um pre-labeled, filter-specific Total Suspended Solids Sample frozen 7 days (TSS) GF/F filter aluminum cup
Biological Oxygen Demand Whole water 1.89 liter poly jug with lid Sample chilled 24 hours (BOD)
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B4 Analytical Methods
Filters, filtrate, and whole water samples prepared on the research vessel (see Program SOP, Appendix A) will be delivered daily, or frozen and shipped immediately following a the completion of a 3-4 day survey, to the nutrient analytical laboratory. The Laboratory will conduct all analyses in accordance with generally accepted laboratory procedures and in keeping with their SOP (Appendix B). Appropriate QC samples will be run with each batch of samples, typically all the samples from a single cruise. Table B4-1 summarizes field and analytical methods and associated detection limits.
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Table B4-1. Summary of field and analytical methods for Long Island Sound Ambient Water Quality Monitoring Program water quality indicators sample analyses (see Program SOP, Appendix A, and Laboratory SOP, Appendix B).
ANALYTICAL METHOD DETECTION VARIABLE FIELD METHOD description and Method Ref. No. LIMIT
Filtration, generally 500mL; automated ion analyzer/colorimetric; Ammonia (NH3) 0.002 mg/L 47mm/0.7um GF/F; filtrate frozen EPA 350.1
Nitrate + Nitrite Filtration, generally 500mL; automated ion analyzer/colorimetric; - - 0.002 mg/L (NO3 ) + (NO2 ) 47mm/0.7um GF/F; filtrate frozen EPA 353.2
Total Dissolved Filtration, generally 500mL; persulfate oxidation; automated ion 0.040 mg/L Nitrogen (TDN) 47mm/0.7um GF/F; filtrate frozen analyzer/colorimetric; EPA 353.2
Particulate Nitrogen Filtration, generally 200mL; high temperature combustion; CHN 0.010 mg/L (PN) 25mm/0.7um GF/F; filter frozen elemental analyzer; EPA 440.0
Orthophosphate 3- (PO4 )/ Dissolved Filtration, generally 500mL; automated ion analyzer/colorimetric; 0.002 mg/L Inorganic Phosphorus 47mm/0.7um GF/F; filtrate frozen EPA 365.2 (DIP)
Total Dissolved Filtration, generally 500mL; persulfate oxidation; automated ion 0.002 mg/L Phosphorus (TDP) 47mm/0.7um GF/F; filtrate frozen analyzer/colorimetric; EPA 365.1
Particulate Filtration, generally 200mL; acid (HCl) extraction; automated ion 0.001 mg/L Phosphorus (PP) 25mm/0.7um GF/F; filter frozen analyzer/colorimetric; EPA 365.1
high temperature combustion; non- Dissolved Organic Filtration, generally 500mL; dispersive infrared analyzer; 0.5 mg/L Carbon (DOC) 47mm/0.7um GF/F; filtrate frozen EPA 415.1
Particulate Carbon Filtration, generally 200mL; high temperature combustion; CHN 0.010 mg/L (PC) 25mm/0.7um GF/F; filter frozen elemental analyzer; EPA 440.0
Filtration, generally 200mL; Dissolved Silica automated ion analyzer/colorimetric; 47mm/0.4um polycarbonate filter; 0.025 mg/L (SiO2) EPA 370.1 filtrate chilled
Filtration, generally 200mL; heated NaOH digestion; automated Particulate (Biogenic) 47mm/0.4um polycarbonate filter; ion analyzer/colorimetric; 0.010 mg/L Silica (BioSi) filter frozen EPA 370.1
Chlorophyll a (Chl a) Filtration, generally 200mL; CH3COCH3(MgCO3) extraction; 0.075 ug/L 25mm/0.7um GF/F; filter frozen fluorometric analysis; EPA 445.0
Total Suspended Filtration, generally 500mL; gravimetric; EPA 160.2 1.0 mg/L Solids (TSS) 47mm/0.7um GF/F; filter frozen
oxygen consumption via dissolved Biological Oxygen whole water sample chilled oxygen measurements at intervals 0.5 mg/L Demand (BOD) from 5 through 30 days
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B5 Quality Control
Field QC Requirements Field QC is associated with site location, collection and handling of water samples, and direct measurements including the CTD profile and Secchi depth.
Station Location Navigation throughout the survey period will make use of vessel-mounted differential GPS. Sampling location will be recorded while the CTD unit is coming to equilibrium, or “soaking”, in the surface water, just prior to the start of the downcast, as coordinates of latitude/longitude in degrees- minutes, expressed to the nearest 0.01 minute (i.e.,00o00.00’). Horizontal accuracies of 0.02 nautical miles are expected with repeatability in excess of this value.
In cases where equipment deployment may pose some risk to Program vessel or equipment, or to another’s property, the crew is allowed to relocate to the nearest location of similar depth (±20%) where sampling can be conducted without unusual risk. This can occur, for example, when lobster pot strings are deployed near a station.
CTD Water Column Measurements (Sea-Bird SBE-19) The quality control related to CTD use includes routine calibration and maintenance. Basic parameters of pressure/depth, temperature, and conductivity/salinity are calibrated annually by the manufacturer (Sea-Bird, Inc.). The calibration report includes the degree of drift since the last calibration, and their reliability has been excellent within the one to two decimal places of interest to the Program. A QC check of depth is provided daily by the research vessel depth finder. Component PAR sensor is also calibrated by the manufacturer (Li-Cor, Inc.), on their recommended schedule of once every two years.
In August 2010, CT DEEP upgraded the dissolved oxygen sensors on its CTDs to the Sea-Bird SBE 43 Dissolved Oxygen Sensor, a polarographic membrane sensor. The sensor is returned to the manufacturer annually for calibration. Following the manufacturer’s guidelines, pre-survey checks of the sensor are performed and compared to values obtained through Winkler titrations. If the sensor has drifted more than 0.2 mg/L the calibration coefficients can be adjusted to the Winkler results. If the adjustment is greater than 20% the unit should be returned to Sea-Bird for recalibration
In August 2010, CT DEP also upgraded its CTDs to include pH sensors. The SBE 18 pH sensor is an add-on auxiliary sensor for profiling CTDs. The sensor uses a pressure-balanced glass electrode/Ag/Ag-Cl reference pH probe to provide in situ measurements at depths up to 1200 meters. The pH sensor is returned to the manufacturer for annual calibration along with the CTD. Additionally, the pH sensor is calibrated using a 3 point calibration prior to every survey and the calibration coefficients can be adjusted as necessary.
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CTD Water Column Measurements (YSI EXO2) In 2017, new YSI EXO2 units are being used concurrently with the SBE-19, with the ultimate goal of switching to the YSI units. This change has been undertaken due to age of the SBE-19s, and the difficulty of updating, as well as the prevalence of the YSI instrumentation in other monitoring programs. The YSI units have the added advantage of sensors that are field- replaceable, helping to minimize data gaps due to sensor failures.
Data is being collected concurrently to compare performance and data comparability between the two units, before employing the YSI units as the primary CTD.
The YSI EXO2 units will be calibrated annually (temperature, salinity), with other parameters (dissolved oxygen) calibrated prior to and/or after each survey. SOPs specific to the use of the YSI EXO2 are currently in development.
Table B5-1. Measurement quality objectives and quality assurance sample information for field water column observations.
Variable QA Sample Type Frequency of QA Data Generated
Field Measurements Performance verification at CTD response vs. calibration standards; Depth Annually certified calibration facility annual drift QC check against vessel’s Difference between CTD station depth Depth Every cast depth finder and on-board depth finder Performance verification at CTD response vs. calibration standards; Temperature Annually certified calibration facility annual drift Performance verification at CTD response vs. calibration standards; Salinity Annually certified calibration facility annual drift Dissolved New membrane installation At least monthly; 100% saturated water; new coefficient Oxygen and calibration always prior to cruise values Dissolved Winkler replicates as part of At least monthly; precision Oxygen sensor calibration always prior to cruise 3-point QC check with At least monthly; pH standard buffers (4.0, 7.0, Difference between probe and standard always prior to cruise 10.0)
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Table B5-2. Measurement quality objectives and quality assurance sample information for laboratory analyses.
Variable QA Sample Type Frequency of QA Analytical Laboratory Measurements Ammonia (NH3) Standards, spikes, lab and field duplicates 10% per batch/cruise Standards, spikes, lab and field duplicates; QC - Nitrate + Nitrite (NO3 +NO2) check against Day 0 whole water BOD sample at up 10% per batch/cruise to 10 stations Total Dissolved Nitrogen (TDN) Standards, spikes, lab and field duplicates 10% per batch/cruise Particulate Nitrogen (PN) Field blanks and field duplicates 10% per batch/cruise 3- Orthophosphate (PO4 ) or (DIP) Standards, spikes, lab and field duplicates 10% per batch/cruise Total Dissolved Phosphorus (TDP) Standards, spikes, lab and field duplicates 10% per batch/cruise Standards, spikes, field blanks, lab and field Particulate Phosphorus (PP) 10% per batch/cruise duplicates Dissolved Org.Carbon (DOC) Standards, spikes, lab and field duplicates 10% per batch/cruise Particulate Carbon (PC) Field blanks and field duplicates 10% per batch/cruise Dissolved Silica (SiO2) Standards, spikes, lab and field duplicates 10% per batch/cruise Standards, spikes, field blanks, lab and field Biogenic Silica (BioSi) 10% per batch/cruise duplicates Chlorophyll a (Chl a) Standards, spikes, field blanks, field duplicates 10% per batch/cruise Standards, field blanks and duplicates; replicates Total Suspended Solids (TSS) 10% per batch/cruise averaged Biological Oxygen Demand (BOD) Field duplicate 10% per batch/cruise
B6 Equipment Testing, Inspection and Maintenance
Preventative Maintenance
Preventative maintenance for all equipment is performed as per manufacturer's instructions and recommended schedule/frequency of performance in order to maintain equipment in good working condition and minimize downtime for all field and laboratory equipment. All preventative maintenance and repairs are performed either by qualified field or lab personnel or by the manufacturer's service engineers. An inventory of spare parts and consumables is maintained to an extent that is sufficient to maintain the operation of all equipment. Except for standard hardware, spare parts are obtained from the manufacturer or their representative or distributor.
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B7 Instrument/Equipment Calibration and Frequency
Calibration Procedures
Field Equipment SeaBird CTD Profiler Units The shipboard instruments will be maintained in accordance with the guidelines provided by the manufacturer. The Sea-Bird CTD profiles will be serviced annually at a certified facility. The profilers will be returned to the manufacturer at approximately 1-year intervals for conductivity, temperature and depth calibration, and general maintenance as recommended by the manufacturer. Two identical CTD units are available and are identified by unique numbers so that maintenance or factory calibration will not affect the survey schedule as they will be on alternate maintenance schedules.
The dissolved oxygen sensor will be calibrated at least monthly, prior to each monthly survey, according to the manufacturer's instructions. For each field instrument a maintenance notebook is maintained, including all calibration records.
Other similarly equipped profiling units and/or individual units or sensors will be operated, maintained, and serviced in accordance with the guidelines provided by the manufacturer.
Laboratory Equipment All laboratory instrument usage, maintenance, calibration, troubleshooting and service are performed according to the procedures documented in each laboratory’s SOP (current versions attached as Appendix B). All chemicals are obtained from the instrument manufacturer or from vendors of scientific supplies. Where appropriate, an instrument logbook is used to record all maintenance and calibration activities.
B8 Inspection of Supplies
Field supplies with definite shelf life will have expiration dates recorded directly on the container and stock will be rotated to ensure the availability of fresh chemicals at all times. An inventory of chemicals and supplies on the research vessel (see Appendix A) allows field staff to ensure that a record of supplies needed is available for subsequent survey preparation activities.
Laboratory supplies and stock solution preparations are documented in each laboratory’s SOP (Appendix B).
B9 Nondirect Measurements
The only nondirect measurement data to be used will be those data previously collected by the Program. These data collected using the same methods and under previously approved QAPPs,
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are used during data review and assessment as they provide for expected parameter ranges. Such provision is not absolute however; previously observed ranges are used only as a guide. No datum will be rejected solely because it does not fall within the previously measured range.
B10 Data Management
All Program data will be managed in an established, electronic Program database.
Field Data Field crews will record most of the raw field data on hardcopy datasheets (Appendix B). The CTD profiling instruments have internal electronic file storage, and these files, if not recovered directly to the onboard computer in real-time, will be downloaded following the cast. Data from manual Winkler dissolved oxygen titrations will be recorded on the Field Data Sheet by the field technician. All field data that is not in electronic form will be transcribed into an electronic database format generally within one week of the survey end date. The Program database (in Microsoft Access) has a Field Data Sheet Entry Form (Appendix B), to be used for all data entry that closely matches the hardcopy forms. All data entry will be performed twice. The two comparable entry logs will then be run through an in-house macro that compares each datum. The process is tracked by forms designed to ensure that all data are reviewed completely (Appendix B). Any differences between the two entries will cause a review of the hardcopy Field Data Sheet to determine the correct datum. Once data are verified to have been entered correctly, they are uploaded to the database and the Field Datasheet Table in the database is updated with the final corrected Entry Form.
Sample Identity Codes All station visits will be uniquely identified by the Station Name and the Cruise Name. In the Program database these two items are consistently used as primary keys; they are required and no matching combinations are allowed. All nutrient data will be further identified by the Depth Code (“S” for Surface, “B” for Bottom) and the Variable measured. Samples containers to be used to store and deliver samples to the analytical laboratory will be pre-labeled with Station Name, Depth Code, Cruise Name, and, where necessary, the variable/variables to be measured. Packages used to store and transport PC/PN and Chlorophyll-a filters, for example, are identical, so that these labels must specify the variable. The date the sample is taken will be added to the containers in the field.
Chain of Custody Forms Sample chain-of-custody (COC) forms will accompany each delivery of samples to the analytical laboratory (Appendix B). COC forms will generally be prepared ahead of time with Station Names and Depth Codes (e.g. B3S = Station B3 Surface water) based on the typical three or four-day station visit plan. The volume of sample filtered, where applicable, and the filter identification number for TSS/PP samples will be recorded on the COC forms by the field crew.
The laboratory will log in all samples when they take possession, assigning a unique laboratory ID number to each unique sample. Laboratory ID numbers will be recorded by the laboratory
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staff directly on the COC forms and a completed copy returned to Program staff.
Data Transformation Field CTD dissolved oxygen data are transformed with the use of manufacturer-provided software. The complete process is described in the Guide to CTD Data Processing, Appendix A. The transformation process is automated so that little if any judgment of the data handler is required. In any case, only very qualified technical staff with significant experience with these files are allowed to conduct this data transformation task. Unusual or errant data require the ability gained from extensive experience and understanding of the data files. Transformed data are reported in the database as Corrected Oxygen, along with the original, raw oxygen data, so that data users may employ their own transformation if they desire.
Laboratory Data Validation Procedures for laboratory data validation are contained in the each laboratory’s SOP (current laboratory SOP, UCONN/CESE, Appendix B). After having undergone all validation procedures at the laboratory, the data are provided to the CTDEEP Program staff.
Analytical and related quality control data are entered and validated by the Program data management personnel. Generally, the electronic files received from the analytical laboratory are compatible with the Program database.
Section C: Assessment/Oversight
C1 Assessments and Response Actions
Field operations lead will be responsible for field and data-entry staff training, review of field and data processing performance, and making corrections. The quality assurance officer will perform regular data review and report issues to the field/database lead. The technical project supervisor will be responsible for field and office audits to ensure that data collections and manipulation are ongoing and in adherence to the quality assurance plan.
C2 Reports to Management
Progress reporting of overall project activities will be submitted as part of CTDEEP’s LISS Semi-annual Performance Reports to EPA, and other LISS reporting by the CTDEEP LISS Coordinator, or as requested by EPA Project Officer. Summertime Hypoxia Survey progress will be reported via biweekly cruise summaries.
Section D: Data Validation and Usability
D1 Data Review, Validation, and Verification
30 Version 1.0 5/09/2017 RFA17069 Section D1
Section B10, Data Management, describes all data handling procedures in the field, laboratory, and program office that lead to survey data ultimately becoming part of the Program database.
Once data are uploaded to the electronic database, Program staff review the data for completeness, outlying or suspect values, comparability of nutrient parameters (TDN > NH3 + NOx, etc.), and to apply any problem codes necessary to the data. Problem data are flagged, but reported values generally remain in the database. Each flag includes a description of the apparent or suspected problem with the datum. All problem data are reported to laboratory QA staff with a request for a) repeat of sample analysis if an archived sample is available; or b) a review of associated laboratory documentation to confirm the reported result.
After being scrutinized during the data entry phase, data are analyzed and plotted to examine any outliers or anomalies. These are examined, verified and corrected if necessary. Field audits are performed by the Field operations lead to assure that all data are collected according to standard operating procedures, and that the collection effort is consistent. All field logs and information will be thoroughly reviewed prior to data analysis to assure that all data were collected uniformly. Any datum collected outside of the standard operating procedures will be examined to determine whether it is representative.
All quality assurance data and reports will be examined prior to data analysis to verify that data were properly and consistently collected. Any deviations in data collection will be taken into account during data analysis. All calibration logs will be examined to determine how well the measurement instruments performed. If there appears to be significant drift in instrument performance, it will be determined whether an adjustment is possible. All raw data files will be kept in paper files. Original (unmanipulated) data will be retained by CTDEEP.
With the exception of the CTD data transformation described in Section B10, above, data reduction will only occur as part of a data report where data are summarized for ease of presentation and to focus on patterns and trends. The Program database, in its entirety, will continue to be available upon request. It is also a goal of the Program to upload all validated data to EPA’s STORage and RETrieval (STORET) data warehouse within 1 year of collection for wider public dissemination of the data collected by the program.
D2 Validation and Verification Methods
All required field data will be entered directly onto field data sheets. All data sheets will be validated in the field for accuracy. The data sheets from a single cruise will be maintained in Program files together with a Data Processing Cover Sheet (Appendix A) that documents the status of CTD data processing to the Program database.
The consistent application of methods provided in the Program SOPs (Appendix A) and this QAPP provides good certainty that the data are both valid and usable. Any missing samples or laboratory accidents will be reported to record completeness and results will be further reviewed
31 Version 1.0 5/09/2017 RFA17069 Section D1
to be sure they are consistent with expected parameter ranges in Long Island Sound.
Any unusual observations will be reviewed by CTDEEP staff involved in the project and, if warranted, outside expertise will be consulted to resolve any problems with data validation and usability.
D3 Reconciliation with Data Quality Objectives
Each survey's data will be reviewed by DEEP Program staff for completeness, compliance with QAPP, correctness, and consistency. Unusual or unexpected results will be reviewed and a determination made as to data usability. Data summaries including annual means, seasonal and long term trends will be reviewed and evaluated for long term project success. Data will be made available upon request to EPA or designees for further review.
32 Version 1.0 5/09/2017 RFA17069 Appendices
APPENDIX A
CTDEEP Long Island Sound Ambient Water Quality Monitoring Program Standard Operating Procedures Manuals
(including Field procedures, Field datasheets, Chain-of-Custody Forms/delivery records, Field data processing procedures, CTD Data processing guide, Database forms, etc.) Version 1.0 5/09/2017 RFA17069 Appendices
APPENDIX B Contract Laboratories Laboratory SOP
University of Connecticut Center for Environmental Science and Engineering Laboratory Standard Operating Procedures
SOP No: 09-033-09 Date Initiated: 12/96 Revision Date: 1/15/16 Page 2 of 97 Table of Contents
Introduction ...... 3 Explanation of Tables ...... 3 Table 1-1—Laboratory Equipment in Use ...... 4 Table 1-2—Analytical Methods of Analysis ...... 5 Table 1-3—Summary of Quality Control Checks ...... 6 Table 1-4—Laboratory Precision and Accuracy Objectives ...... 7 Table 1-5—Organization of Monthly Data/QC Report ...... 8 Procedure Prior to Sample Analysis ...... 9 Procedure for Sample Receipt ...... 10 The Lachat Quick Chem 8500 ...... 11 Particulate Carbon and Particulate Nitrogen ...... 15 Nitrate and Nitrite EPA 353.2 ...... 22 Ammonia EPA 350.1...... 28 Dissolved Inorganic Phosphorus EPA 365.1 ...... 34 Total Dissolved Nitrogen EPA 353.2 ...... 40 Total Dissolved Phosphorus EPA 365.1 ...... 47 Dissolved Silica EPA 370.1 ...... 53 Biogenic Silica EPA 370.1 ...... 59 Particulate Phosphorus EPA 365.1 ...... 66 Total Suspended Solids EPA 160.2 ...... 72 Chlorophyll EPA 445.0 ...... 75 Dissolved Organic Carbon EPA 415.1 ...... 80 Biochemical Oxygen Demand 405.1 Modified ...... 86 Data Review ...... 89 Sample Holding Times ...... 90 Calibration and QA Acceptance Policy ...... 92 Field Quality Control (QC) and Other Quality Control Techniques ...... 97
Created By Steph Kexel SOP No: 09-033-09 Date Initiated: 12/96 Revision Date: 1/15/16 Page 3 of 97 Introduction
This laboratory operation manual is a document delineating the procedures used by the Center for Environmental Sciences and Engineering’s (CESE) Nutrient Laboratory at the University of Connecticut to analyze seawater samples for the Connecticut Department of Energy and Environmental Protection's (CT DEEP) Bureau of Water Management Long Island Sound Study (LISS).
Explanation of Tables
Table 1-1 presents a list of major equipment to be used for the analysis of nutrients. Additional equipment and materials to be used on this project are listed in the individual standard operating procedures (SOPs).
Table 1-2 summarizes the analytical methods used in the analysis of seawater samples.
Table 1-3 summarizes the quality control (QC) checks required for each group of analyses.
Table 1-4 summarizes the precision and accuracy objectives of the laboratory methods. The calibration verifications rely on analysis of samples traceable to the National Institute of Standards and Technology (NIST) or the Environmental Protection Agency (EPA). These are used as controlling elements for the methods, and ensure that the calibration curve used is representative for the entire analytical run, and that the precision meets the requirements shown in Table 1-4. All QC checks are stored in the CESE database with each sample delivery group (SDG). Data reports can be obtained with a sample delivery group number to allow quality assurance (QA) review of any sample analysis and evaluation of any of the associated Quality Assurance checks.
Table 1-5 shows the organization of the monthly QC/QA and quarterly reports submitted to the CT DEEP.
Created By Steph Kexel SOP No: 09-033-09 Date Initiated: 12/96 Revision Date: 1/15/16 Page 4 of 97 Table 1-1—Laboratory Equipment in Use
Equipment Manufacturer Model Serial #
QuickChem Lachat 8500 040600000007
Total Organic Shimadzu TOC-L CPH H54214900076AE Carbon Analyzer Fluorometer Turner Trilogy 720000403
CHN Analyzer Perkin Elmer Series 2 24N1021602
Microgram Mettler XP26 1128431375 Balance Drying Oven Fisher Isotemp 176 131
Autoclave (2) Market Forge STM-E
Muffle Furnace Fisher Scientific Isotemp 550- 1511071280908 126
Created By Steph Kexel SOP No: 09-033-09 Date Initiated: 12/96 Revision Date: 1/15/16 Page 5 of 97 Table 1-2—Analytical Methods of Analysis
Parameter MDL Instrument Method
Ammonia 0.002 mg/L Lachat Quick Chem EPA 350.1 (NH3) Nitrate + Nitrite 0.002 mg/L Lachat Quick Chem EPA 353.2 (NOx) Chlorophyll-a 0.100 µg/L Turner Fluorometer EPA 445.0 (CHL-a) Calculated Ortho-phosphate 0.001 mg/L Lachat Quick Chem EPA 365.1 (DIP) Dissolved Silica 0.006 mg/L Lachat Quick Chem EPA 370.1 (SiO2) Dissolved Organic Carbon 0.0787 mg/L Shimadzu TOC-L High EPA 415.1 (DOC) Temperature Combustion Total Dissolved Phosphorus 0.002 mg/L Lachat Quick Chem EPA 365.1 (TDP) Total Dissolved Nitrogen 0.019 mg/L Lachat Quick Chem EPA 353.2 (TDN) Particulate Nitrogen 0.004 mg/L CHN High Temperature EPA 440 (PN) Combustion Particulate Phosphorus 0.0001 mg/L Lachat Quick Chem EPA 365.1 (PP) Calculated HCl extraction Particulate Carbon 0.022 mg/L CHN High Temperature EPA 440 (PC) Combustion Biogenic Silica 0.002 mg/L Lachat Quick Chem EPA 370.1 (Bio SiO2) NaOH Extraction Total Suspended Solids 3 mg/L Gravimetric EPA 160.2 (TSS)
Created By Steph Kexel SOP No: 09-033-09 Date Initiated: 12/96 Revision Date: 1/15/16 Page 6 of 97 Table 1-3—Summary of Quality Control Checks
NH3, NOX, DIP, SiO2, TDN, TDP, Bio SiO2 and PP
1. Calibration Curve, five points to seven points. 2. One method blank every 10 samples (where applicable). 3. Calibration Curve Verification every 10 samples. 4. Calibration Blank Verification every 10 samples. 5. Spike Recovery analysis every 10 samples. 6. Laboratory Duplicate analysis every 10 samples.
DOC
1. Calibration Curve, 4 points. 2. Calibration Curve Verification every 10 samples. 3. Calibration Blank Verification every 10 samples. 4. Spike Recovery analysis every 10 samples. 5. Laboratory Duplicate analysis every 10 samples.
PN/PC
1. Calibration Curve, one point. 2. One method blank per 10 samples. 3. One K-Factor every 10 samples.
TSS
1. Analysis of NIST weights to verify calibration. 2. Calibration Verification every delivery group.
CHL-a
1. Calibration Curve, three points 2. One method blank per 20 samples 3. Calibration Verification every 20 samples 4. Spike Recovery analysis every delivery group.
Created By Steph Kexel SOP No: 09-033-09 Date Initiated: 12/96 Revision Date: 1/15/16 Page 7 of 97 Table 1-4—Laboratory Precision and Accuracy Objectives
Parameter Method Relative % Difference % Recovery NH3 EPA 350.1 <15 85-115 NOx EPA 353.2 <15 85-115 DIP EPA 365.1 <15 85-115 SiO2 EPA 370.1 <15 85-115 TDP EPA 365.1 <15 85-115 TDN EPA 353.2 <15 85-115 DOC EPA 415.1 <15 85-115 PN EPA 440.0 NA 85-115 PC EPA 440.0 NA 85-115 Bio SiO2 EPA 370.1 <15 85-115 PP EPA 365.1 <15 85-115 TSS EPA 160.2 NA 85-115 CHL-a EPA 445.0 NA 85-115
Created By Steph Kexel SOP No: 09-033-09 Date Initiated: 12/96 Revision Date: 1/15/16 Page 8 of 97 Table 1-5—Organization of Monthly Data/QC Report
Cover LetterI. ll. Project Narrative Discussion of any problems with analytical results, quality control, handling, labeling or holding times, and if applicable, what corrective action was taken.
IIl. Hardcopy Spreadsheet of monthly data
V. I Copies of all Chains of Custody submitted to the laboratory
V. Table for each parameter, which contains holding times, analysis date and QC results for:
Initial and Continuing Blank Verification Initial and Continuing Calibration Verification Laboratory Duplicate Analyses Field Blank Analyses Field Duplicate Analyses Laboratory Blank Analyses Laboratory Spike Analyses
VI. Electronic submission will include a results database and a QC database.
Created By Steph Kexel SOP No: 09-033-09 Date Initiated: 12/96 Revision Date: 1/15/16 Page 9 of 97 Procedure Prior to Sample Analysis
Total Suspended Solids
Pre-weighed filters are available in the laboratory and are used by CT DEEP sampling personnel for LISS TSS samples. The filters are supplied by Environmental Express. (ProWeigh Filters cat # F93447MM). Each 47mm filter comes with an individual tin on which is printed the filter’s identification number and weight, and is certified for accuracy by the manufacturer.
Particulate Carbon and Nitrogen Filter Pad Preparation
Loosely arrange 25 mm, 0.7µm glass fiber filter pads in crucibles and place the crucibles in the muffle furnace for combustion at 500°C for 1 hour. The crucibles are then cooled, transferred to a desiccator and allowed to equilibrate at room temperature. The filter pads are then transferred to clean, dust free plastic bottles, and sealed for delivery to the CT DEEP.
Prior to packing, acceptance testing must be performed on each batch of filters using 2 filters per batch of 100 filters. The filters are analyzed for particulate carbon and nitrogen, and if the analysis shows carbon or nitrogen contamination the lot must be discarded and a new lot prepared. The analysis procedure must then be repeated.
Biogenic Silica Filter Pad Preparation
No preparation is required for the 47 mm, 0.4µm poly-carbonate membrane filter pad.
Particulate Phosphorus Filter Pad Preparation
No preparation is required for the 47 mm, 0.7µm glass microfiber filter pads.
Chlorophyll-a Filter Pad Preparation
No preparation is required for the 0.7µm, 25mm glass fiber filter pad.
Preparation of 250mL and 125mL Polyethylene Sample Bottles.
Acid soak with dilute hydrochloric acid (HCl) for at least 15 minutes by fully submerging and ensuring the bottle is void of air bubbles in an acid bath.
Rinse 3 times with deionized water. Fill with 20-30mL of DI and swirl to ensure all inside surfaces are rinsed with DI. Shake out DI in between rinses to reduce to a minimum the carryover of DI from rinse to rinse.
Place in clean drying area with open end towards the counter top.
Biogenic Silica Centrifuge Tubes
No preparation or washing is required.
Created By Steph Kexel SOP No: 09-033-09 Date Initiated: 12/96 Revision Date: 1/15/16 Page 10 of 97
Procedure for Sample Receipt
After delivery and signing of chain of custody sheets, information is taken from the field data sheets and entered into Sample Master, the Laboratory Information Management System (LIMS). Each sample is assigned a unique laboratory identification number which consists of a group identification number, which is a continuously increasing number generated by Sample Master, and a sample ID that increases in ascending order based on the arrival time at the laboratory. The laboratory group number is designated as the sample delivery group (SDG) number, which is then used for reporting purposes.
Information recorded into the LIMS includes date of collection, date of delivery, parameters requested and client contact information.
After the samples are grouped, labels are placed on the containers, and the samples are placed in appropriate storage until analysis can be performed.
Sample Requirement and Preservation
Supply Test Requirement Replicate Storage
PC/PN 25mm GF/F Duplicate Aluminum Foil/Frozen
PP 47mm GF/F Duplicate Aluminum Foil/Frozen
TSS 47mm GF/F Single Proweigh Pre-labeled Tin
CHl-a 25mm GF/F Duplicate Aluminum Foil/Frozen
BioSiO2 47mm PCM/F Single Centrifuge Tube/Frozen
3- NOX-N, PO4 -P 250mL Bottle Single Frozen NH3-N, TDP TDN, DOC
SiO2 125mL Bottle Single Refrigerate 4ºC (do not freeze)
Created By Steph Kexel SOP No: 09-033-09 Date Initiated: 12/96 Revision Date: 1/15/16 Page 11 of 97 The Lachat Quick Chem 8500
Scope and Application
The Lachat QuickChem 8500 is a wet-chemistry continuous flow-analyzer that is used in laboratories for the automation of complex chemical reactions. It uses the principle of continuous flow-analysis (CFA) for fully automatic sample analysis. Samples are mixed with reagents in a continuously flowing stream. In the Nutrients Laboratory, chemistries currently run on the Lachat for the LISS are as follows:
Nitrate + Nitrite as N Total Dissolved Nitrogen as N Ammonia as N Dissolved Inorganic Phosphorus as P Total Dissolved Phosphorus as P Particulate Phosphorus as P Silica as SiO2 Biogenic SiO2
The Lachat consists of 4 main components. These are the XYZ Sampler, the reagent pump, the Chemistry manifold with detectors, and the computer with monitor and the printer.
The XYZ Sampler is a computer controlled random access sampler designed to automatically introduce samples in a preprogrammed sequence into the analytical system.
The reagent pump is in contact with peristaltic pump tubing, spinning at a predetermined speed to provide precise volume delivery of sample and reagents. Pump tubes and lines are made of flexible PVC. The individual pump platens hold the pump tubes in place and ensure correct pressure against the pump rollers for positive sample/reagent flow. At the rear of the pump are the power button, the standby button and the buttons to vary pump speed.
Chemical reactions are carried out on the chemistry module. The samples are injected into a continuous “carrier” stream. The carrier is free of the analyte being measured and thus serves as a baseline. The chemistry manifolds contain the required components to complete color development. Samples are inserted into the carrier stream; develop color when mixed with reagents, and stand out in absorbency value against the carrier baseline background. The information regarding absorbency value collected at the detector head is fed to the computer of the system unit and is displayed on the monitor screen. Samples show as peaks against the flat baseline. The software uses the peak area to determine the concentration of analyte.
There are four channels on the Chemistry Module. The channel that is closest to the analyst when looking at the instrument is channel 4. This channel runs Nitrite. Channel 3 runs Total Nitrogen and Nitrate + Nitrite. Channel 2 runs Dissolved Inorganic Phosphorus, Total Dissolved Phosphorus, and Particulate Phosphorus. This channel is switched out for the SiO2 analysis. Channel one runs Ammonia.
Omnion version 3.0 is the software that controls the Lachat. Results are calculated from peak area.
References
QuickChem 8500 FIA Automated Ion Analyzer Operation Manual. Lachat Instruments, 2004.
Software User Guide: Omnion 3.0. Hach Company, 2004.
Created By Steph Kexel SOP No: 09-033-09 Date Initiated: 12/96 Revision Date: 1/15/16 Page 12 of 97 Associated SOP’s
Refer to “SOP” titled “Hazardous Waste SOP” for proper waste disposal.
Refer to the notebook titled “SOP’s” located in the nutrients laboratory.
Safety
Waste effluents must be kept separately from each other. The waste streams from the phosphorous manifold and the nitrate/nitrite manifold must not be combined.
Be sure to check each specific method for hazards related to wastes and reagent composition.
Refer to the University of Connecticut’s Environmental Health and Safety chemical health and safety web page at:
http://www.ehs.uconn.edu/ppp/index.php
A hard copy of the Chemical Hygiene Plan can be found on the notebook rack located on the lab bench. Also refer to the Hazardous Waste SOP.
Materials
Chemistry Module Peristaltic Pump XYZ Auto-sampler Computer Printer See individual methods for each analyte for other materials
Procedure
Instrument Start-up Procedure
Turn on the auto sampler, place the pump platens in place and start the pump. Turn on the power to the chemistry module and boot up the computer.
Activate the software by selecting “Omnion” icon on the desktop. Click “Open” at the top of the menu.
Select the correct method: Nitrate + Nitrite, TDN, TDP etc. A template run will pop up with all of the pertinent QC, Standard, Blank and spike information. If nothing needs to be changed, enter the sample ID’s for each corresponding cup number. Acceptable limits are already programmed into the software.
To change quality assurance limits, activate the run properties window and click on the tab for “sample”. This will bring up the data quality management (DQM) specifics and they may be changed here. Be sure that the proper sample is highlighted in the run worksheet.
Methods have already been developed that utilize the Refractive Index Correction in the software for salt water matrices. It is not necessary to matrix match standards and carrier to samples as the software will select an area of the peak to integrate that omits the refractive index dip that occurs at the start of a peak.
Created By Steph Kexel SOP No: 09-033-09 Date Initiated: 12/96 Revision Date: 1/15/16 Page 13 of 97
Make sure that the proper wavelength of filter is in the proper detector location (see individual methods for wavelengths).
Make sure that the proper length sample loop is attached between valve positions 1 and 4 (see individual methods).
Ensure that effluent lines are in the proper hazardous waste receptacle.
After 10 minutes of rinsing with deionized Water, put the reagents in their proper reagent bottles. Let reagents run through lines for at least 10 minutes before proceeding.
If running the NOx manifold, make sure the cadmium column is active at this point.
If running ammonia, put reagent lines in this order: buffer, phenol, nitroprusside and bleach, letting each flow through the manifold before adding another line.
Run Set-up Procedure
Select the run worksheet window to make it active and then enter the sample calibration and sample IDs. When a sample is highlighted select the “Sample” tab at the top of the run properties window to change acceptable limits.
The run must have this order:
Type Concentration Location Calibrant Calibrant cup position 346 Calibrant Calibrant cup position 347 Calibrant Calibrant cup position 348 Calibrant Calibrant cup position 349 Calibrant Calibrant cup position 350 Calibrant Calibrant cup position 351
To add samples, QCs, blanks, spikes or calibrants, click on the corresponding pre-entered value to highlight lines and copy and past them to the desired location. All of the DQM test requirements will transfer with the copied cells.
New lines may be inserted into the software by clicking on the sample number and right clicking on the mouse and either “insert sample(s)” or at the end of a sheet you can add lines by right clicking on the mouse and “append one or many”.
Any run may be modified while running samples as long as it’s not close to the end of the run. Once a run is completed, you must re-calibrate and set up a new run.
At the end of the run, the last sample must be PQL.
The software generates a filename for each run created. The filename will be OM DD MM YYYY HH MM SS AM or PM.OMN. If there are multiple runs for the same day, the date will be the same, but the hour/min/second will change. Be sure to export the run information under the file tab to print the run log then put it in the run log book.
Starting a Run
Select the green arrow “start” button on the top of the main menu tool bar.
Created By Steph Kexel SOP No: 09-033-09 Date Initiated: 12/96 Revision Date: 1/15/16 Page 14 of 97 During the Run
After the calibration has been completed, check the correlation coefficient. To view the calibration graph, click on the chart recorder window’s chart icon at the left side of the window.
If the software is not capturing the entire peak in the peak expectation window, wait for 2 full peaks to appear on the screen and stop the run. When prompted to stop the run, select “yes”. Then double click on the peak and the peak windows will appear. Click and drag the sides of the peak expectation window to encompass the entire peak. Right click on the peak and select “Adjust Peak Expectation Window”. This should capture the entire peak. Once this step is completed, the software is ready to continue with the calibration.
Select the green arrow “start” button to begin the run again. Ensure that there is enough standard solution in the sample cups to continue and verify that the calibration coefficient is 0.995 or greater before continuing.
Once calibration passes, ensure that the QC and BLK pass and continue with the run.
See each individual method for proper spike concentrations.
After the Run is Complete
Although this is a rare occasion, it may be necessary to delete a point from the calibration curve. Only one point may be deleted from the curve, and once the point is deleted, the correlation coefficient must yield a value of 0.997 or greater. If a point is deleted, the deleted standard concentration must be re-made and re-run at the end of the run to verify that the standard was made incorrectly or that instrument problems precluded an accurate sample analysis. If the lowest point (the PQL) is deleted from the curve, the next highest standard becomes the PQL and all data between this higher point and the MDL must be flagged.
To review data, select the yellow “custom report format” button at the top of the main menu. On the table tab, ensure that the Cup No. and Manual Dilution Factor boxes are checked off.
In the calculations tab, ensure that under sample preparation, the multiply concentration by manual dilution factor box is checked off.
In the charts tab, ensure that the calibration, DQM tests, and channel data display boxes are all checked off and that the “show 10 peaks per chart” for all peaks is checked off.
Print the report, then double click on the run worksheet so that the entire run is highlighted, then click on “run” at the top of the screen, and then select “export worksheet data”. This will print the run log to put in the proper run log book.
Shutting Down the Instrument
If running NOx, turn the cadmium column off-line.
Place all reagent lines in deionized water for 10 minutes, pulling reagent lines out of solution in the opposite order that they were placed in reagents (see individual methods for correct order of reagent line orders). Pump air through the lines until no liquid can be seen running through the manifolds.
Dump out the sample probe rinse bottle and sample cups. Shut down the computer. Shut off the chemistry module. Shut the pump off and remove the platens. Shut off the auto sampler.
Created By Steph Kexel SOP No: 09-033-09 Date Initiated: 12/96 Revision Date: 1/15/16 Page 15 of 97 Particulate Carbon and Particulate Nitrogen
Scope and Application
This SOP is used for analysis of particulate carbon (PC) and particulate nitrogen (PN) in filtered seawater samples. The holding time is 28 days.
The CHN analyzer uses a combustion method to convert the sample elements to simple gases (CO2, H2O, and N2). The sample is first oxidized in a pure oxygen environment using classical reagents.
The products that are produced in the combustion zone include CO2, H2O, and N2. Elements, such as halogens and sulfur, are removed by scrubbing reagents in the combustion zone. The resulting gases are homogenized and controlled to exact conditions of pressure, temperature, and volume.
The homogenized gases are allowed to de-pressurize through a column where they are separated in a stepwise, steady-state manner and detected as a function of their thermal conductivities (Perkin Elmer CHNS/O Manual).
The Method Detection Limit (MDL) and Practical Quantitation Limit (PQL) for this analysis are determined yearly. For current MDL and PQL limits, see the chart entitled Method Detection Limit Determination.
References
CHNS/O Elemental Analyzer Operation Manual. Perkin Elmer, Revision D. Shelton, CT 06484.
Associated SOP’s
Refer to “SOP” titled “Hazardous Waste SOP” for proper waste disposal.
Refer to the notebook titled “SOP’s” located in the nutrients laboratory.
Safety
Combustion and reduction tubes are treated as hazardous waste, are labeled with contents and placed in hazardous waste bin. When packing tubes, use proper protective gear and work in hood as reagents are hazardous.
Refer to the University of Connecticut’s Environmental Health and Safety chemical health and safety web page at: http://www.ehs.uconn.edu/ppp/index.php
A hard copy of the Chemical Hygiene Plan can be found on the notebook rack located on the lab bench. Also refer to the Hazardous Waste SOP.
Created By Steph Kexel SOP No: 09-033-09 Date Initiated: 12/96 Revision Date: 1/15/16 Page 16 of 97 Materials
Perkin Elmer CHNS/O Elemental Analyzer 2400 Series II Combustion and Reduction Tubes Reagents (see Perkin Elmer Manual)
Procedure
Starting up the Instrument
Begin by turning on the three tanks of gases (helium, nitrogen and compressed air). Power up the instrument by flipping the switch on the bottom-right hand side of the instrument and ensure that the printer is on. The CHN will not run if the printer is off.
The instrument will prompt to enter the time, date (expressed as d/m/yr) and then will go through a series of pressure checks. Throughout this SOP whenever a button is depressed on the instrument, the button identification will be within
The instrument will ask for an operator id. Enter initials and press
The instrument will now display the fill pressure. Depress
Next, the run counter will display run counts for the combustion tube, the reduction tube and the vial receptacle. Press
Next, the instrument will display the furnace temperatures for each zone. Depress
Next the instrument will run through a self check and will pressurize to about 700mmHg.
The instrument will prompt if a helium and oxygen purge should be completed. Depress
If the combustion and reduction tubes have been changed, a leak check must be completed on the system. Press
Press
Created By Steph Kexel SOP No: 09-033-09 Date Initiated: 12/96 Revision Date: 1/15/16 Page 17 of 97 Depress
Press the
Check that the furnace temperature is rising by repeating the monitor step above.
When the furnace reaches full temperature, purge the gases by pressing
Now the instrument must warm up for at least 4 hours, but it is preferable to warm it up overnight.
Beginning a run
Once heated, blanks must be run until they reproduce themselves. To run a blank, press
o Carbon +/- 30 o Hydrogen +/- 100 o Nitrogen +/- 16
Conditioning New Tubes
When new tubes are inserted in the instrument, they must be conditioned with k-factors. Run a blank,
Running Blanks
The instrument must be blanked out before analysis. Run 10-15 blanks if the instrument has been started after a period of shutdown. Initially, the blanks will be air blanks, so that the high concentrations of analytes will be purged from the system. Then run 5 tin disk blanks. From now on, any time a blank is run, it MUST be a tin disk.
The system does not average blank runs consecutively. Instead, it involves comparisons among three blank values from the latest run, the prior run, and the current running average resulting in three possible scenarios: (1) The value of the latest run is compared with the current running average. (2) When the difference between these two values meets the specified criterion limit, the values are averaged and become the NEW running average. Otherwise, a second comparison is made. (3) The value of the latest run is compared with the value of the prior run. If the difference between these two values meets the same specified criterion limit, these two values are averaged and become the NEW running average. If neither of these above meets the specified criterion limit, the current running average remains in effect.
Created By Steph Kexel SOP No: 09-033-09 Date Initiated: 12/96 Revision Date: 1/15/16 Page 18 of 97 Calibrating the Instrument
The instrument is calibrated using a 1-point calibration using an acetanilide k-factor. K-factors are weighed on the microbalance and weights are recorded in the k-factor logbook. The ideal weight for k-factors is around 2.0mg.
The run sequence for calibrating the instrument is as follows:
o Blank tin disk
Run K-factors until these limits are met. It usually only requires three consecutive k-factor runs and then proceed to the next blank.
o Blank tin disk
The k-factor values are generally within the following expected range:
. C 16.5 +/-3.5 . H 50.0 +/-20.0 . N 6.0 +/-3.0
After calibrating, set the instrument up to run water filters by pressing
Running Samples in an Auto Run
Samples may be run individually by the method described above or by setting up an auto run. The sample tray holds 60 samples but as the tray rotates, additional samples may be added to the auto run. Be very careful entering auto run data because once entered, changing the information is not possible. If an error is made, the entire auto run must be deleted and re- entered.
To set up an auto run, place samples in appropriate tray position. To clear previous auto run information, select the
Created By Steph Kexel SOP No: 09-033-09 Date Initiated: 12/96 Revision Date: 1/15/16 Page 19 of 97 Next, enter sample ID for each tray position. Press
After entering the run, print the run set-up by following the instructions in the previous step.
When finished, press
Place the auto sampling tray on top of the CHN making sure that the tray clicks into place so the advance arm is seated into position. Position 1 should be left empty when filling the sampling tray as there is a hole in it for the sample to drop into the instrument. After the tray is seated, place the 1st sample in position one. It should drop down into the instrument.
To start the run, press
Packing New Columns
When packing columns follow the diagram in the CHN manual or that is in the drawer next to the hood. Be sure to pack the combustion column by packing with a pipette.
When packing the reduction column, use a funnel to pour the copper reagent into the tube and use a shaker to pack the column tight. Shake column 3-4 times between adding the copper reagent.
Sample Preparation-PC/PN water filters
Flat tin disks are expensive, so be sure to use only one per sample. They can stick together. Also, the instrument blanks are based on 1 tin disk, so if two are stuck together, it will alter the result.
Use forceps to gently tap the edges of the tin disks, this will separate them.
The CT DEEP will fold filters in ½ in the field. They must be baked in the oven overnight at 105°C. Filters may be baked in the tin foil pouches that they were submitted in, but the pouch must be opened before being placed in the oven. After filters are cooked, close tin foil pouch and place in desiccator until ready for preparation.
After cooked, using forceps and gloves fold filter in ¼ and place point at edge of tin disk. Be sure to use a clean working platform. Fold tin and filter, rolling filter in tin disk so that no portion of the filter is showing. Fold each end of rolled tin and place in the pellet press. The press has a removable metal cylinder that if placed with the ridged edge up, will compact the filter, when flipped over with ridge down, it will pop out the filter after pressed. The height of the platform may be adjusted by turning clock-wise to raise the platform up. Ensure that a tightly compacted pellet comes out of the press by raising the platform throughout preparation as necessary.
Record sample tray positions in the CHN sample preparation logbook.
Created By Steph Kexel SOP No: 09-033-09 Date Initiated: 12/96 Revision Date: 1/15/16 Page 20 of 97 When running filters, it is necessary to run a blank filter. These have been prepped according to the LISS methods, which are to muffle the filters for 1 hour at 500°C before giving them to the CT DEEP to bring to the field. A batch is set aside during this preparation for instrument analysis and to verify the filters are blank before giving them to the CT DEEP. These filters are run every 10 samples and are prepped the same way. They are called an ID BLK because when entering the sample ID as the numeric-alpha related code, the screen says ID BLK. A tin disk blank will have a sample ID of simply “blank”.
K-factors are still entered with weight values when running filters.
K-factor Preparation
When prepping the K-factor it is very important to be extremely careful not to drop any sample out of the tin disk. It is also important to make sure 1 disk is used per sample.
First fold tin disk into a cone and then place cone on balance platform and zero.
Next, take tin and place ~2mg of K-factor in bottom of cone and weigh, and record weight in log book.
After weighing, be sure to take cone out of balance without dropping any sample. Fold up tin with sample enclosed in tin disk, being careful not to lose any sample. IF SAMPLE IS LOST, IT WILL ALTER THE RESULT GREATLY!!!
K-factors are run as a separate QC and when run, are entered into the instrument as a sample. o The recovery values for the QC are: . C = 71.09% H = 6.71% N = 10.36
Shutting Down the Instrument
First, turn off the furnace by pressing
Next, press
Once the instrument has cooled to about 100°C, press
Next, press
Press code <5>
Turn off the instrument and shut off all of the gasses.
Created By Steph Kexel SOP No: 09-033-09 Date Initiated: 12/96 Revision Date: 1/15/16 Page 21 of 97 Quality Control
• PN/PC quality control checks: o One tin disk blank is run per 10 samples. o One blank filter is run per 10 samples. o One k-factor is run per 10 samples.
Created By Steph Kexel SOP No: 09-033-09 Date Initiated: 12/96 Revision Date: 1/15/16 Page 22 of 97 Nitrate and Nitrite EPA 353.2
Scope and Application
EPA Method 353.2 is the reference method for measuring nitrate + nitrite in seawater by automated colorimetric determination. This section provides a stepwise procedure for bench use by laboratory personnel.
This method (Lachat method number 31-107-04-1-A) was developed for the quantitative analysis of nitrates in water and seawater. The applicable range is 0 to 0.5mg/L as nitrogen. Samples higher in range may be diluted and re-run. The holding time for this analysis is 28 days.
This method is based on automated colorimetric determination and is restricted to the use by or under the supervision of analysts experienced in the use of auto analyzers.
This method may be used for analysis of NOX-N (nitrate + nitrite) or nitrite alone. NOx-N values - - are obtained by activating the cadmium column and calibrating with NO3 standards. Nitrite (NO2 - -N) is calibrated with NO2 -N standards and the cadmium column is not activated. Reagents - - remain the same. The Nitrate (NO3 -N) value is calculated by subtracting the Nitrite (NO2 -N) value from the Nitrate + Nitrite (NOx-N) value. In the LISS dissolved NOX-N is analyzed and reported.
Summary of Method
The whole water sample is filtered through a 47mm GF/F filter in the field. The filtrate is frozen at –10°C or below until analysis can be completed (samples must not be preserved with mercuric chloride or thiosulfate, as these degrade the copper-cadmium column used in this analysis). Analysis is completed within 28 days from arrival date at the laboratory. Samples for nitrate + nitrite are analyzed using flow injection on a Lachat. Nitrate is reduced to nitrite at pH 7.5 in a copperized cadmium column. The nitrate reduced to nitrite, plus any free nitrite present, reacts under acidic conditions with sulfanilamide to form a diazo compound that couples with N-1- Naphthylethylenediamine dihydrochloride to form a reddish-purple azo dye that is measured at 520nm. For nitrite analyses the cadmium column is not used.
The Method Detection Limit (MDL) and Practical Quantitation Limit (PQL) for this analysis are determined yearly. For current MDL and PQL limits, see the chart entitled Method Detection Limit Determination.
This method is based on automated colorimetric determinations and is restricted to the use by, or under the supervision of analysts experienced in the use of auto analyzer equipment.
The instruments are calibrated with a minimum of a six point curve (including the blank) at the time of analysis (obtained from AccuStandard). The calibration curve is then verified by an external quality control sample from Fisher, an independent supplier. Supplier guidelines are used for making up the quality control solutions, as well as for information on the true value and acceptable value range for the analytes being measured in each quality control sample.
An initial calibration check along with an initial calibration blank, demonstrate that the instrument is capable of acceptable performance at the beginning of the sample analysis. In order to ensure continuing acceptable performance, a continuing calibration check and continuing calibration blank are run every tenth sample. For every 10 samples, a laboratory spike analysis and a laboratory duplicate analysis are performed. At the end of the run a practical quantitation limit (PQL) is run for further quality control verification.
Created By Steph Kexel SOP No: 09-033-09 Date Initiated: 12/96 Revision Date: 1/15/16 Page 23 of 97 Interferences
Build up of suspended matter in the cadmium column will restrict flow. Look for a "jerking" action in one or several of the pump tube lines as evidence of such a blockage. Nitrate-nitrogen is, however, found in a soluble state, so pre-filtering of samples should be sufficient to keep lines clear.
Low results are possible for samples high in metals concentrations such as iron or copper. (1.0 g . per liter) Na2EDTA 2H2O can be added to the buffer to reduce this interference.
Samples that contain large concentrations of oil and grease will coat the surface of the cadmium. Pre-extracting the sample with an organic solvent eliminates this interference.
References
31-107-04-1-A, August 19, 2003. Determination of Nitrate/Nitrite in Brackish or Seawater by Flow Injection Analysis. Lachat Applications Group, Lachat Instruments, Loveland CO.
EPA Method 353.2. Determination of Nitrate-Nitrite Nitrogen by Automated Colorimetry. Revision 2.0, August 1993. Environmental Monitoring Systems Laboratory, Office of Research and Development, U.S. Environmental Protection Agency, Cincinnati, Ohio.
Standard Method 4500-N. Nitrogen. Page 4-99—4-123, 20th Edition, 1998, Standard Methods for the Examination of Water and Wastewater.
Associated SOP’s
Refer to “SOP” titled “Hazardous Waste SOP” for proper waste disposal.
Refer to the notebook titled “SOP’s” located in the nutrients laboratory.
Safety
Cadmium crystals are a known carcinogen; use caution when reactivating the cadmium for column repacking.
Reagents are hazardous and are made in the hood. Protective gear is worn when making reagents.
Ensure that waste lines from the detector are going to the proper hazardous waste jug located under the instrument.
Refer to the University of Connecticut’s Environmental Health and Safety chemical health and safety web page at:
http://www.ehs.uconn.edu/ppp/index.php
A hard copy of the Chemical Hygiene Plan can be found on the notebook rack located on the lab bench. Also refer to the Hazardous Waste SOP.
Created By Steph Kexel SOP No: 09-033-09 Date Initiated: 12/96 Revision Date: 1/15/16 Page 24 of 97 Materials
Lachat Auto Analyzer Cadmium column
Procedure
Reagent Preparation
Unless otherwise specified, all chemicals should be ACS grade or equivalent. DI water refers to high quality reagent water, TYPE I or TYPE II as defined in ASTM Standards, Part 31, D1193-74. When making reagents, date the container in which the reagent is stored, initial it, and write out the entire name of the reagent and hazard warnings. Many of the following solutions are stable indefinitely. Otherwise, shelf life is noted.
• Ammonium Chloride Buffer
We are currently using Fisher hydrochloric acid (catalog no. A144S-212), Fisher disodium EDTA (catalog no. S311-500), and Fisher ammonium hydroxide (catalog no. A669S-212).
Hydrochloric Acid (concentrated) 105mL Ammonium Hydroxide 95mL Disodium EDTA 1.0g
Be sure to make this reagent in the hood. Wear all protective gear! Add about 500mL DI water to a 1000mL amber poly bottle. Carefully pour in 105mL concentrated hydrochloric acid, rinse graduated cylinder with DI, then, with a new graduated cylinder, pour in 95mL ammonium hydroxide. Again rinse graduated cylinder with DI. Add 1.0 g disodium EDTA, dissolve and dilute to the mark. Invert to mix and adjust the pH to 8.5 with 2 N HCl or 15N NaOH solution. Solution is stable for one month.
• Sulfanilimide Color Reagent
We are currently using Fisher sulfanilamide (catalog no. AC132855000), Acros NED (catalog no. AC42399-0250), and Fisher phosphoric acid (catalog no. A242-212).
Phosphoric Acid (85% soln. by wt.) 100mL Sulfanilamide 40.0g NED (N-(1-napthyl)ethylenediamine dihydrochloride 1.0g
To a 1L volumetric flask, add about 600mL DI water then add 100mL 85% phosphoric acid, 40g sulfanilamide and 1.0g NED. Shake to wet. Dilute to the mark, invert to mix, and then mix with stir bar. Store in a dark bottle and discard when the solution turns pink, roughly one month.
Cadmium-Copper Reduction Column
Pre-packed cadmium columns are available from Lachat/HACH (Lachat part/order no. 50237A). Instructions for repacking columns in the laboratory are at the end of the Nitrate/Nitrite SOP and can be made available upon request.
Created By Steph Kexel SOP No: 09-033-09 Date Initiated: 12/96 Revision Date: 1/15/16 Page 25 of 97 Standard Preparation
Working standards can be made by weight or volume. Standards are made using a 1000µg/mL stock certified from AccuStandard or another source different from the QC. Standards are made weekly.
Stock Standard, 10.0 mg/L N
- AccuStandard Stock (NO3 -N) 1mL DI Water, q.s. 100mL final vol.
- In a 100mL volumetric flask containing about 80mL of DI add 1mL of stock AccuStandard NO3 -N standard. Dilute to 100mL with DI and mix thoroughly. Record the information in the stock standard logbook.
Working Standard Solutions mL(g) 10mg/L Stock mg/L N
5.0 0.500 3.0 0.300 1.0 0.100 0.5 0.050 0.25 0.025 0.1 0.010
Transfer aliquots of stock 10mg/L stock as noted above to individual 100mL volumetric flasks. Dilute to volume with DI water and mix thoroughly. Record the information in working standard logbook. Prepare fresh weekly.
- - A Nitrite (NO2 -N) QC of the same concentration as the NO3 -N QC must also be made when running with the cadmium column to ensure that the cadmium column is working efficiently. A 90% recovery is considered acceptable. A lower recovery than this indicates that the cadmium column must be replaced.
Sample Preparation
Sample turbidity is removed by filtration though a 47mm GF/F filter prior to analysis. Turbidity absorbing in the range of 550 nanometers (nm) will present a positive bias.
Preserve the sample by freezing at -10°C or below until the time of analysis. Sample containers are to be rinsed with 1:1 hydrochloric acid, followed by DI water and finally by an aliquot of the sample itself. Disposable plastic sample tubes are used during analysis to avoid contamination from improper washing of glass tubes.
Generally, 5mL of sample is spiked with 100µL of the 10ppm stock standard, yielding a spike concentration of 0.196ppm.
The quality control sample (QC) is made up in 100mL volumes per every 60 or so samples. Larger quantities are necessary if running large batches of samples. Generally, a QC concentration of 0.3ppm is used and is made fresh daily.
Created By Steph Kexel SOP No: 09-033-09 Date Initiated: 12/96 Revision Date: 1/15/16 Page 26 of 97 Instrumental Analysis
It is assumed that the user is basically familiar with the appearance and location of the various parts of the Lachat. It is also assumed that a method for running NOx analyses has already been created, and that the user is familiar with basic system operations. For a physical description of the instrument and any related software information, see the section entitled “The Lachat Quick Chem 8500”.
Ensure that the correct size sample loop (150cm) is attached at the manifold valve between ports 1 and 4.
Ensure that the 520nm wavelength filter is in the detector.
Ensure that the sample line is attached to port 6 of the switching valve and that the reagents are all pumping properly.
General Analyzer Information
When using the cadmium column, check the efficiency of the column daily by analyzing equal concentrations of nitrate and nitrite standards. The efficiency should be >90%.
Introduce the ammonium chloride reagent into the chemistry manifold first, allow the system to flow for about a minute, and then introduce the sulfanilamide.
When using the cadmium column, ALWAYS ensure that the column is activated when ALL reagents are pumping through the system. Likewise, make sure the column is in the “off” position at the end of the run before taking reagent lines out of solution for the wash step.
Cadmium columns are purchased from Lachat instruments (CAT # 50237A), however cadmium may be regenerated in the laboratory according to Lachat publication WI#J20008. This publication is available upon request.
Calculations
• Percent recovery for the spike is determined using the following formula: − BA )( %R = x100 C
Where: A = measured value in mg/L for the sample + spike B = measured value in mg/L for the original sample C = concentration of the spike in mg/L
• Relative percent difference for the duplicate is calculated by the following formula: − BA )( RPD = x100 []()+ BA 2/
Where: A = the value in mg/L for the first run of the sample B = the value in mg/L for the second run of the sample
Created By Steph Kexel SOP No: 09-033-09 Date Initiated: 12/96 Revision Date: 1/15/16 Page 27 of 97
• To determine the column efficiency, use the following formula: [NO- - N] E = 3 x100 NO- − N [ 2 ]
Where: E = column efficiency - NO3 -N = concentration of nitrate standard - NO2 -N = concentration of nitrite standard
Quality Control
A certified second source quality control sample (purchased from Fisher) is analyzed for every delivery group (or every 10 samples) and the value must be within 85-115% recovery to be considered acceptable.
A spike is analyzed for every delivery group (or every 10 samples). The percent recovery must fall within the 85-115% recovery to be acceptable.
A duplicate is analyzed for every delivery group (or every 10 samples) and the relative percent difference must be < 20%.
A blank is analyzed for every delivery group or every 10 samples and the value must fall below the practical quantitation limit (PQL) to be considered acceptable. The concentration of the PQL is the low standard.
A second quality control sample is analyzed at the end of the run and is the concentration of the PQL, or the lowest standard. Acceptable ranges for the PQL are 50-150% recovery.
Cadmium column efficiency is analyzed with every calibration.
Other System Notes
Light interference filter: 520nm Sample Loop Size: 150cm
Created By Steph Kexel SOP No: 09-033-09 Date Initiated: 12/96 Revision Date: 1/15/16 Page 28 of 97 Ammonia EPA 350.1
Scope and Application
EPA Method 350.1 is the reference method for measuring ammonia in seawater by automated colorimetric determination with phenate. This section provides a stepwise procedure for bench use by laboratory personnel.
This method (Lachat ammonia method number 31-107-06-1-B) was developed for the quantitative analysis of ammonia in water and seawater. The applicable range is 0 to 0.5mg/L of ammonia as nitrogen (NH3-N). Seawater samples higher in range may be diluted and analyzed using the same method.
The Method Detection Limit (MDL) and Practical Quantitation Limit (PQL) for this analysis are determined yearly. For current MDL and PQL limits, see the chart entitled Method Detection Limit Determination.
Contamination of samples with ammonia is a problem of great concern. Ammonia is ubiquitous in the environment. Ammoniated floor strippers and waxes are strictly prohibited in the laboratory.
This method is based on automated colorimetric determinations and is restricted to the use by, or under the supervision of, analysts experienced in the use of auto analyzer equipment.
Summary of Method
The whole water sample is filtered through a 47mm GF/F glass-fiber filter in the field. The filtrate is then frozen at or below –10°C until analysis can be completed. Analysis is completed within 14 days from arrival date at the laboratory. Samples for ammonia are analyzed by an automated procedure on a Lachat, utilizing the Berthelot reaction.
Ammonia in the sample reacts with alkaline sodium phenate and then sodium hypochlorite to form indophenol blue. A solution of EDTA is added to the sample stream to eliminate the precipitation of the hydroxides of calcium and magnesium. Sodium nitroprusside is added to intensify the blue color.
The Lachat is calibrated with a minimum of a six-point curve (including the blank) at the time of analysis (purchased from AccuStandard). The calibration curve is then verified by an external quality control sample from Fisher, an independent supplier). Supplier guidelines are used for making up the quality control solutions, as well as for information on the true value and acceptable value range for the analytes being measured in each quality control sample.
An initial calibration check along with an initial calibration blank, demonstrate that the instrument is capable of acceptable performance at the beginning of the sample analysis. In order to ensure continuing acceptable performance a continuing calibration check and continuing calibration blank are run every tenth sample. For every 10 samples, a laboratory spike analysis and a laboratory duplicate analysis are performed.
Created By Steph Kexel SOP No: 09-033-09 Date Initiated: 12/96 Revision Date: 1/15/16 Page 29 of 97 Interferences
Calcium and magnesium ions could precipitate if present in sufficient concentration. EDTA is added to the sample stream to rectify this problem.
Color (as well as certain organic species) can cause interference.
Method interferences may be caused by contaminants in the reagent water, reagents, glassware and other sample processing apparatus that may bias analytical results.
References
31-107-06-1-B, August 2003. Determination of Ammonia in Brackish or Seawater by Flow Injection Analysis. Lachat Instruments, Loveland, CO.
EPA Method 350.1. Determination of Ammonia Nitrogen by Semi-Automated Colorimetry. Revision 2.0, August 1993. Environmental Monitoring Systems Laboratory, Office of Research and Development, U.S. Environmental Protection Agency, Cincinnati, Ohio.
Standard Method 4500-NH3 G Ammonia by Automated Phenate. Page 4-103—4-112, 20th Edition, 1998, Standard Methods for the Examination of Water and Wastewater.
Associated SOP’s
Refer to “SOP” titled “Hazardous Waste SOP” for proper waste disposal.
Refer to the notebook titled “SOP’s” located in the nutrients laboratory.
Safety
Reagents are hazardous and are made in the hood. Protective gear is worn when making reagents.
Phenol is a known carcinogen and is hazardous. Use caution when making this reagent. There are special gloves in the Phenol cabinet. Be sure to wear them when using this reagent.
Ensure that waste lines from the Lachat are going to the proper hazardous waste jug located under the instrument.
Refer to the University of Connecticut’s Environmental Health and Safety chemical health and safety web page at:
http://www.ehs.uconn.edu/ppp/index.php
A hard copy of the Chemical Hygiene Plan can be found on the notebook rack located on the lab bench. Also refer to the Hazardous Waste SOP.
Created By Steph Kexel SOP No: 09-033-09 Date Initiated: 12/96 Revision Date: 1/15/16 Page 30 of 97 Materials
Lachat QuickChem8500
Procedure
Reagent Preparation
Unless otherwise specified, all chemicals should be ACS grade or equivalent. DI water refers to high quality reagent water, TYPE I or TYPE II as defined in ASTM Standards, Part 31, D1193-74. When making reagents, date the container in which the reagent is stored, initial it, write out the entire name of the reagent and hazard class. Many of the following solutions are stable indefinitely. Otherwise, shelf life is noted.
• Phenol
We are currently using Fisher Scientific phenol crystals (catalog no. A92-100) and Fisher sodium hydroxide (catalog no. S318-3).
CAUTION: Phenol is very poisonous, causes severe burn, and is rapidly absorbed into the skin. Wear gloves and safety glasses.
Phenol Crystals 83g Sodium Hydroxide 32g DI Water, q.s. 1000mL final vol.
In a volumetric flask, fill ¾ with deionized water and dissolve 32 g of sodium hydroxide in approximately 600mL of water, dissolve and cool under cold tap water, being sure not to introduce tap water into the volumetric flask. Add 83g of phenol crystals and dilute to one liter with DI water and mix thoroughly. Store the reagent in an amber poly bottle. This material is corrosive, and is stable for about one week or until brown.
• Sodium Hypochlorite Solution
We are currently using Fisher bleach (Cat # SS290-1) that contains 5.65% NaOCl and no additives.
Sodium Hypochlorite Solution, 5.65%(Clorox) 50mL DI Water, q.s. 50mL
Dilute 50mL of bleach to 50mL with DI water and mix thoroughly. Prepare fresh daily.
• Sodium Nitroprusside
We are currently using Fisher sodium nitroferricyanide dehydrates, 99% (sodium nitroprusside, catalog no. S350-100).
Sodium Nitroprusside 1.75g DI water, q.s. 1000mL final vol.
Fill a volumetric flask ¾ with deionized water and add 1.75g of sodium nitroprusside in 1000mL of water and mix thoroughly. Store the solution in an amber poly bottle. Degas with helium for 5 minutes. Solution is stable for one week.
Created By Steph Kexel SOP No: 09-033-09 Date Initiated: 12/96 Revision Date: 1/15/16 Page 31 of 97 • Buffer Chelating Reagent
We are currently using Fisher EDTA (catalog no. S311-500) and Fisher sodium hydroxide (S399-212).
EDTA 50g Sodium Hydroxide 11g DI Water, q.s. 1000mL final vol.
In a 1L volumetric flask, fill ¾ with DI water, and add 50g of EDTA and 11g sodium hydroxide. Dilute to one liter and mix well. Store the solution in a clear poly bottle. Degas for 5 minutes with helium. Solution is stable for one week.
Standard Preparation
Working standards can be made by weight or volume. Standards are made using a 1000µg/mL stock certified from AccuStandard or another source different from the QC.
• Stock Standard, 10.0mg/L N
AccuStandard Stock (Ammonium NH4-N) 1mL DI water, q.s. 100mL final vol.
In a 100mL volumetric flask containing about 80mL of DI add 1mL of stock AccuStandard ammonium standard. Dilute to 100mL with DI and mix thoroughly. Record the standard information in the stock standard logbook. Standards must be made fresh weekly.
Working Standard Solutions:
mL(g) 10mg/L Stock mg/L N
5.0 0.500 3.0 0.300 1.0 0.100 0.5 0.050 0.25 0.025 0.1 0.010
Transfer aliquots of stock 10mg/L stock as noted above to individual 100mL volumetric flasks. Dilute to volume with DI water and mix thoroughly. Record the information in working standard logbook. Prepare fresh weekly.
Sample Preparation
Sample turbidity is removed by filtration though a 47mm GF/F filter prior to analysis. Turbidity absorbance in the range of 660 nanometers (nm) will present a positive bias.
Preserve the filtrate by freezing at –10°C or below until the time of analysis. Sample containers are to be rinsed with 1:1 hydrochloric acid, followed by DI water and finally by an aliquot of the sample itself. Disposable sample tubes are used during analysis to avoid contamination from improper washing of glass tubes.
Generally, 5mL of sample is spiked with 100µL of the 10ppm stock standard, yielding a spike concentration of 0.196ppm.
Created By Steph Kexel SOP No: 09-033-09 Date Initiated: 12/96 Revision Date: 1/15/16 Page 32 of 97
The quality control sample (QC) is made up in 100mL volumes per every 60 or so samples. Larger quantities are necessary if running large batches of samples. Generally, the concentration of the QC is 0.3ppm and is made fresh daily.
Instrumental Analysis
It is assumed that the user is basically familiar with the appearance and location of the various parts of the Lachat QuickChem Autoanalyzer. It is also assumed that a method for running ammonia analysis has already been created, and that the user is familiar with basic system operations. For a physical description of the instrument and any related software information, see the section entitled “The Lachat Quick Chem 8500”.
The pH of the final reaction solution must lie within certain limits. Collect the solution from the flow cell waste line to verify the pH is between 11.5 and 11.9 if issues arise.
It is very important to introduce the reagent lines in this order: buffer, phenol, nitroprusside then bleach. When removing reagent lines when shutting down the instrument, do so in reverse order to prevent calcium precipitate from forming on the inside of the coils.
Ensure that the pump tubes are pumping reagents and that the sample line is hooked up to port 6 of the switching valve.
Calculations
• Percent recovery for the spike is determined using the following formula: (A − B) %R = x100 C
Where: A = measured value in mg/L for the sample + spike B = measured value in mg/L for the original sample C = concentration of the spike in mg/L
• Relative percent difference for the duplicate is calculated by the following formula: (A − B) RPD = x100 + [(A B)/ 2]
Where: A = the value in mg/L for the first run of the sample B = the value in mg/L for the second run of the sample
Created By Steph Kexel SOP No: 09-033-09 Date Initiated: 12/96 Revision Date: 1/15/16 Page 33 of 97 Quality Control
A certified second source quality control sample (purchased from Fisher) is analyzed for every delivery group (or every 10 samples) and the value must be within 85-115% recovery to be considered acceptable.
A spike is analyzed for every delivery group (or every 10 samples). The percent recovery must fall within the 85-115% recovery to be acceptable.
A duplicate is analyzed for every delivery group (or every 10 samples). The duplicate relative percent difference (RPD) must be below 20%.
A blank is analyzed for every delivery group or every 10 samples and the value must fall below the practical quantitation limit (PQL) to be considered acceptable. The concentration of the PQL is the low standard.
A second quality control sample is analyzed at the end of the run and is the concentration of the PQL, or the lowest standard. Acceptable ranges for the PQL are 50-150% recovery.
Other System Notes
Chemistry Manifold 1 Light interference filter: 660 nm Special instructions: The reaction module for ammonia determinations comes equipped with a heating coil that heats the sample stream (after the addition of the reagents) to 37°C, which promotes better color development. This coil should be given 15 minutes to warm up before any samples are run.
Created By Steph Kexel SOP No: 09-033-09 Date Initiated: 12/96 Revision Date: 1/15/16 Page 34 of 97 Dissolved Inorganic Phosphorus EPA 365.1
Scope and Application
EPA Method 365.1 (Aspila, EPA) is the reference method for measuring dissolved inorganic phosphorus (DIP) in seawater by automated colorimetric determination. This section provides a stepwise procedure for bench use by laboratory personnel.
This method (Lachat ortho-phosphorus method number 31-115-01-1-H) was developed for the quantitative analysis of DIP in seawater. The applicable range is 0.010 to 0.500mg/L of DIP. Samples higher in range may be diluted and re-run or analyzed by recalibrating with higher concentration.
This method is based on automated colorimetric determination and is restricted to the use by or under the supervision of analysts experienced in the use of auto analyzers.
The holding time for this method is 28 days.
Summary of Method
For dissolved inorganic phosphorus, the whole water sample is filtered though a 47mm GF/F filter in the field. The filtrate is then preserved by freezing at or below -10°C until analysis is completed within 28 days. Samples for DIP are analyzed by an automated procedure on the Lachat QuickChem flow injection analyzer. The analysis depends on the formation of a phosphomolybdenum blue complex, which is read colorimetrically at 880 nm.
The Method Detection Limit (MDL) and Practical Quantitation Limit (PQL) for this analysis are determined yearly. For current MDL and PQL limits, see the chart entitled Method Detection Limit Determination.
This method is based on automated colorimetric determinations and is restricted to the use by, or under the supervision of, analysts experienced in the use of auto analyzer equipment.
The Lachat is calibrated with a minimum of a six point curve (including the blank) at the time of analysis (obtained from AccuStandard). The calibration curve is then verified by an external quality control sample from Fisher, an independent supplier. Supplier guidelines are used for making up the quality control solutions, as well as for information on the true value and acceptable value range for the analytes being measured in each quality control sample.
An initial calibration check along with an initial calibration blank, demonstrate that the instrument is capable of acceptable performance at the beginning of the sample analysis. In order to ensure continuing acceptable performance a continuing calibration check and continuing calibration blank are run every tenth sample. For every 10 samples, a laboratory spike analysis and a laboratory duplicate analysis are performed. At the end of the run a practical quantitation limit (PQL) is run for further quality control verification.
Created By Steph Kexel SOP No: 09-033-09 Date Initiated: 12/96 Revision Date: 1/15/16 Page 35 of 97 Interferences
Arsenate is analyzed similarly to ortho-phosphorus, and will cause interference if present. Reducing the arsenic acid to arsenious acid with sodium bisulfite should alleviate this problem. Sodium bisulfite treatment will also take care of any problems with high iron concentration (>50mg/L).
Any silica present will react with the reagents in this method, forming a pale blue complex which also absorbs at 880nm. Because the method is very sensitive to small amounts of phosphorus, sensitivity to silica is also high. Glass should therefore be avoided if possible. Reagents should be made and stored in plastic. Silica forms a pale blue complex that also absorbs at 880nm and is generally insignificant because a silica concentration of approximately 30mg/L would be required to produce a 0.005 P/L positive error in orthophosphate.
Acidity among samples, standards and blanks should be carefully controlled. Large variations in acidity will affect sample and/or standard peaks.
Good glassware cleaning procedures should always be used. Phosphorus contamination is a constant problem. Proper glassware washing protocol should elevate this problem.
References
31-115-01-1-H, August 2003. Determination of Orthophosphate by Flow Injection Analysis. Lachat Instruments, Loveland, CO.
EPA Method 365.1. Determination of Phosphorus by Semi-Automated Colorimetry. Revision 2.0, August 1993. Environmental Monitoring Systems Laboratory, Office of Research and Development, U.S. Environmental Protection Agency, Cincinnati, Ohio.
Standard Method 4500-P A, B, G and H Phosphorous: Flow Injection Method. Page 4- 139 – 4-153, 20th Edition, 1998, Standard Methods for the Examination of Water and Wastewater.
Associated SOP’s
Refer to “SOP” titled “Hazardous Waste SOP” for proper waste disposal.
Refer to the notebook titled “SOP’s” located in the nutrients laboratory.
Safety
Reagents are hazardous and are made in the hood. Protective gear is worn when making reagents.
Ensure that waste lines from the Lachat are going to the proper hazardous waste jug located under the instrument.
Refer to the University of Connecticut’s Environmental Health and Safety chemical health and safety web page at:
http://www.ehs.uconn.edu/ppp/index.php
Created By Steph Kexel SOP No: 09-033-09 Date Initiated: 12/96 Revision Date: 1/15/16 Page 36 of 97 A hard copy of the Chemical Hygiene Plan can be found on the notebook rack located on the lab bench. Also refer to the Hazardous Waste SOP.
Materials
Lachat QuickChem Auto Analyzer
Procedure
Reagent Preparation
Unless otherwise specified, all chemicals should be ACS grade or equivalent. DI water refers to high quality reagent water, TYPE I or TYPE II as defined in ASTM Standards, Part 31, D1193-74. When making reagents, date the container in which the reagent is stored, initial it, and write out the entire name of the reagent and hazard class. Many of the following solutions are stable indefinitely. Otherwise, shelf life is noted.
• Stock Antimony Potassium Tartrate
We are currently using Fisher antimony potassium tartrate (catalog no. A867-250).
Antimony Potassium Tartrate 1.61g DI Water, q.s. 500mL final vol.
Dissolve 1.61 g of antimony potassium tartrate in about 400mL of DI water in a 500mL volumetric flask. Dilute to 100mL with DI water and mix thoroughly. Store the solution in a dark plastic container. Solution is stable for one month.
• 1N Sulfuric Acid
We are currently using Fisher sulfuric acid (catalog no. SA176-4).
Sulfuric Acid 28mL DI Water, q.s. 1000mL final vol.
Fill an amber poly bottle ¾ with DI water and add 28mL of sulfuric acid. Dilute to 1000mL with DI water and mix thoroughly. Solution is stable for one month.
• Stock Ammonium Molybdate
We are currently using Fisher ammonium molybdate (catalog no. A674-500).
Ammonium Molybdate 20g DI Water, q.s. 500mL final vol.
Fill amber poly bottle ¾ with DI water and add 20g of ammonium molybdate. Dilute to 500mL with DI water and mix thoroughly. Solution is stable for one month. .
Created By Steph Kexel SOP No: 09-033-09 Date Initiated: 12/96 Revision Date: 1/15/16 Page 37 of 97 • Molybdate Color Reagent
We are currently using Fisher Sulfuric Acid (catalog no. SA176-4).
Stock Antimony Potassium Tartrate Solution 72mL Stock Ammonium Molybdate 213mL Sulfuric Acid 35mL DI Water, q.s. 1000mL final vol.
To a 1 liter volumetric flask add about 500mL of DI water, then 35mL of concentrated sulfuric acid. Swirl to mix. Add 213mL of stock ammonium molybdate solution and 72mL of stock antimony potassium tartrate solution. Dilute to 1000mL with DI water and mix thoroughly. Degas with helium for at least 5 minutes. Store in a dark plastic container. This solution is stable for one month.
• Ascorbic Acid
We are currently using Fisher, L-ascorbic acid (catalog no. BP351-500) and Fisher SDS (catalog no. BP166-100).
Ascorbic Acid 60g SDS 1g DI Water, q.s. 1000mL final vol.
In a 1L volumetric add 60g of ascorbic acid in approximately 800mL DI water. Dilute to 1000 mL with DI water and mix thoroughly. Degas for a minimum of 5 minutes. Pour into clear plastic bottle and add 1g of SDS and swirl gently. This solution is stable for 5 days. Store the solution in a clear poly container.
Standard Preparation
Working standards can be made by weight or volume. Standards are made using a 1000ug/mL stock certified from AccuStandard or another source different from the QC.
• Stock Standard, 10.0mg/L N
AccuStandard Stock (Phosphorus) 1mL DI Water, q.s. 100mL
In a 100mL volumetric flask containing about 80mL of DI add 1mL of stock AccuStandard phosphorus standard. Dilute to 100mL with DI and mix thoroughly. Record the information in the stock standard logbook.
Working Standard Solutions:
mL(g) 10mg/L Stock mg/L P
5.0 0.500 3.0 0.300 1.0 0.100 0.5 0.050 0.25 0.025 0.1 0.010
Created By Steph Kexel SOP No: 09-033-09 Date Initiated: 12/96 Revision Date: 1/15/16 Page 38 of 97 Transfer aliquots of stock 10mg/L stock as noted above to individual 100mL volumetric flasks. Dilute to volume with DI water and mix thoroughly. Record the information in working standard logbook. Prepare fresh weekly.
Sample Preparation
Turbidity absorbing in the range of 880 nanometers (nm) will present a positive bias.
Preserve the sample by freezing at -10°C or below until the time of analysis. Sample containers are to be rinsed with 1:1 hydrochloric acid, followed by DI water and finally by an aliquot of the sample itself.
Generally, 5mL of sample is spiked with 100µL of the 10ppm stock standard, yielding a spike concentration of 0.196ppm.
The quality control sample (QC) is made up in 100mL volumes per every 60 or so samples. Larger quantities are necessary if running large batches of samples. Generally, the QC concentration is 0.3ppm and is made fresh daily.
Instrumental Analysis
It is assumed that the user is basically familiar with the appearance and location of the various parts of the Lachat. It is also assumed that a method for running ortho- phosphorus analysis has already been created, and that the user is familiar with basic system operations. For a physical description of the instrument and any related software information, see the section entitled “The Lachat Quick Chem 8500”.
Ensure that reagents are pumping through all pump tubes and that the sample line is connected to port 6 of the switching valve.
Ensure that the proper method has been selected, either for fresh water analysis or one that utilizes the refractive index correction for seawater samples.
Calculations
• Percent recovery for the spike is determined using the following formula: − BA )( %R = x100 C
Where: A = measured value in mg/L for the sample + spike B = measured value in mg/L for the original sample C = concentration of the spike in mg/L
• Relative percent difference for the duplicate is calculated by the following formula: − BA )( RPD = x100 []()+ BA 2/
Where: A = the value in mg/L for the first run of the sample B = the value in mg/L for the second run of the sample
Created By Steph Kexel SOP No: 09-033-09 Date Initiated: 12/96 Revision Date: 1/15/16 Page 39 of 97 Quality Control
A certified second source quality control sample (purchased from Fisher) is analyzed for every delivery group (or every 10 samples) and the value must be within 85-115% recovery to be acceptable.
A spike is analyzed for every delivery group (or every 10 samples). The percent recovery must fall within the 85-115% recovery to be acceptable.
A duplicate is analyzed for every delivery group (or every 10 samples) and the relative percent difference must fall below 20%.
A blank is analyzed for every delivery group or every 10 samples and the value must fall below the practical quantitation limit (PQL) to be considered acceptable. The concentration of the PQL is the low standard.
A second quality control sample is analyzed at the end of the run and is the concentration of the PQL, or the lowest standard. Acceptable ranges for the PQL are 50-150% recovery.
Other System Notes
Chemistry manifold 2 Light interference filter: 880 nm Special instructions: The reaction module for phosphorus determinations comes equipped with a heating coil that heats the sample stream (after the addition of the reagents) to 37°C, which promotes better color development. This coil should be given 15 minutes to warm up before any samples are run.
Created By Steph Kexel SOP No: 09-033-09 Date Initiated: 12/96 Revision Date: 1/15/16 Page 40 of 97 Total Dissolved Nitrogen EPA 353.2
Scope and Application
This is an alkaline persulfate oxidation method (D'Elia 1977) on seawater for total dissolved nitrogen (TDN). Nitrate is the sole N product of the digestion and is determined by an automated colorimetric procedure. This section provides a stepwise procedure for bench use by laboratory personnel.
EPA Method 353.2 is the reference method for measuring nitrate + nitrite in seawater by automated colorimetric determination, and SM 4500 N C is the digestion. This section provides a stepwise procedure for bench use by laboratory personnel.
This method is based on automated colorimetric determination and is restricted to the use by or under the supervision of analysts experienced in the use of auto analyzers. The applicable range is from 0.0—2.0mg/L. The holding time for this analysis is 28 days.
Samples are extracted with potassium persulfate and N values are obtained by activating the cadmium column and calibrating with combined NO3--N + NH4-N standards for the TDN calibration curve.
Summary of Method
For total dissolved nitrogen (TDN) analysis, the whole water sample is filtered though a 47mm GF/F filter in the field. 10mL of sample is then pipetted into a screw cap test tube. The pipetted sample is then frozen at –10°C or below until digestion can be completed. 5mL of an oxidizing reagent (potassium persulfate) is then added. The tubes are placed in an autoclave at 235°F for 60 minutes. The sample is allowed to sit overnight and then is ready for analysis of TDN. Analysis is completed within 28 days of arrival at the laboratory.
Every 10 samples, a preparation blank, a laboratory spike and a laboratory duplicate analysis are performed. Samples are analyzed using flow injection on the Lachat. Nitrate is reduced to nitrite at pH 7.5 in a copperized cadmium column. The nitrate reduced to nitrite, plus any free nitrite present, reacts under acidic conditions with sulfanilamide to form a diazo compound that couples with N-1-Naphthylethylenediamine dihydrochloride to form a reddish-purple azo dye that is measured at 550nm.
The Method Detection Limit (MDL) and Practical Quantitation Limit (PQL) for this analysis are determined yearly. For current MDL and PQL limits, see the chart entitled Method Detection Limit Determination.
This method is based on automated colorimetric determinations and is restricted to the use by, or under the supervision of, analysts experienced in the use of auto analyzer equipment.
The analyzer is calibrated with a minimum of a six point curve (including the blank) at the time of analysis (obtained from AccuStandard). The calibration curve is then verified by an external quality control sample from Fisher, an independent supplier. Supplier guidelines are used for making up the quality control solutions, as well as for information on the true value and acceptable value range for the analytes being measured in each quality control sample.
Created By Steph Kexel SOP No: 09-033-09 Date Initiated: 12/96 Revision Date: 1/15/16 Page 41 of 97 Initial calibration verification, along with an initial calibration blank, demonstrates that the instrument is capable of acceptable performance at the beginning of the sample analysis. In order to ensure continuing acceptable performance a continuing calibration check and continuing calibration blank are run every tenth sample. For every 10 samples, a laboratory spike analysis and a laboratory duplicate analysis are performed. At the end of the run a practical quantitative limit (PQL) is run for further quality control verification.
Interferences
Build up of suspended matter in the cadmium column will restrict flow. Look for a "jerking" action in one or several of the pump tube lines as evidence of such a blockage. Nitrate nitrogen is, however, found in a soluble state, so pre-filtering of samples should be sufficient to keep lines clear.
Low results are possible for samples high in metals concentrations such as iron or copper. . (1.0g per liter) Na2EDTA 2H2O can be added to the buffer to reduce this interference.
Samples that contain large concentrations of oil and grease will coat the surface of the cadmium. Pre-extracting the sample with an organic solvent eliminates this interference.
References
10-107-04-1-C, March 2003. NitrateDetermination of Nitrate/Nitrite in Surface and Wastewaters by Flow Injection Analysis. Lachat Instruments, Loveland, CO.
31-107-044-A, September 18, 2003. Determination of Total Nitrogen in Brackish or Seawater by Flow Injection Analysis. Lachat Instruments Applications Group, Loveland, CO.
EPA Method 353.2. Determination of Nitrate-Nitrite Nitrogen by Automated Colorimetry. Revision 2.0, August 1993. Environmental Monitoring Systems Laboratory, Office of Research and Development, U.S. Environmental Protection Agency, Cincinnati, Ohio.
Standard Method 4500 –N C. Nitrogen: Persulfate Method. Page 4-102—4-103, 20th Edition, 1998, Standard Methods for the Examination of Water and Wastewater.
Associated SOP’s
Refer to “SOP” titled “Hazardous Waste SOP” for proper waste disposal.
Refer to the notebook titled “SOP’s” located in the nutrients laboratory.
Safety
Samples are disposed of in a hazardous waste jug and are properly labeled.
Reagents are hazardous and are made in the hood. Protective gear is worn when making reagents.
Ensure that waste lines from the Lachat are going to the proper hazardous waste jug located under the instrument.
Created By Steph Kexel SOP No: 09-033-09 Date Initiated: 12/96 Revision Date: 1/15/16 Page 42 of 97 Refer to the University of Connecticut’s Environmental Health and Safety chemical Health and safety web page at:
http://www.ehs.uconn.edu/ppp/index.php
A hard copy of the Chemical Hygiene Plan can be found on the notebook rack located on the lab bench. Also refer to the Hazardous Waste SOP.
Materials
Market Forge Autoclave Lachat Quick Chem 8500 Cadmium column
Procedure
Reagent Preparation
Unless otherwise specified, all chemicals should be ACS grade or equivalent. DI water refers to high quality reagent water, TYPE I or TYPE II as defined in ASTM Standards, Part 31, D1193-74. When making reagents, date the container in which the reagent is stored, initial it, and write out the entire name of the reagent. Many of the following solutions are stable indefinitely. Otherwise, shelf life is noted.
• Digestion Reagent – Potassium Persulfate
We are currently using Fisher sodium hydroxide (catalog no.S318-3) and Fisher potassium persulfate (catalog no. P282-500). The potassium persulfate should be kept in a desiccator to minimize the possibility of oxidization.
Sodium Hydroxide 6.0g Potassium Persulfate 40.2g Boric Acid 12.0g DI Water, q.s. 1000mL final vol.
In a 1L small mouth clear poly bottle, dissolve 6.0g sodium hydroxide in about 600mL of water. When the sodium hydroxide is completely dissolved, add 40.2g potassium persulfate and 12.0g of boric acid and dissolve with a magnetic stirrer. Dilute to 1 liter with DI water and mix thoroughly. This solution is unstable and should be made immediately prior to use.
Created By Steph Kexel SOP No: 09-033-09 Date Initiated: 12/96 Revision Date: 1/15/16 Page 43 of 97 • Ammonium Chloride Buffer
We are currently using Fisher hydrochloric acid (catalog no. S318-3) and Fisher ammonium hydroxide (catalog no. A669S-212).
Hydrochloric Acid (concentrated) 210mL Ammonium Hydroxide 190mL Disodium EDTA 2.0g
Be sure to make this reagent in the hood. Wear all protective gear! Add about 500mL DI water to a 1000mL glass volumetric flask. Carefully pour in 210mL concentrated hydrochloric acid and rinse well. With a new graduated cylinder, pour in 190mL ammonium hydroxide and rinse. Add 1.0g disodium EDTA, dissolve and dilute to the mark. Invert to mix and adjust the pH to 8.5 with 15N sodium hydroxide solution. Solution is stable for one month.
• Sulfanilamide Color Reagent
We are currently using Fisher sulfanilamide (catalog no. O4525-100), Acros NED (catalog no. AC42399-0250), and Fisher phosphoric acid (catalog no. A242SK-2212).
Phosphoric Acid (85% soln. by wt.) 200mL Sulfanilamide 80.0g NED (N-(1-napthyl)ethylenediamine dihydrochloride 2.0g
To a 1L volumetric flask, add about 600mL DI water then add 200mL 85% phosphoric acid, 80g sulfanilamide and 2.0g NED. Shake to wet, and stir to dissolve for 30 minutes. Dilute to the mark, invert to mix. Store in a dark bottle and discard when the solution turns pink, roughly one month.
• 2N Hydrochloric Acid
We are currently using Fisher hydrochloric acid (catalog no. S318-3).
Hydrochloric Acid (concentrated) 16.6mL DI Water, q.s. 100mLfinal vol.
Add 50mL DI water to a graduated cylinder. Pour in carefully 16.6mL hydrochloric acid and dilute to 100mL with DI water.
Cadmium-Copper Reduction Column
Pre-packed cadmium columns are used with the Lachat nitrate/nitrite manifold are available from Lachat/HACH (Lachat part/order no. 50237A).
Standard Preparation
Working standards can be made by weight or volume. Standards are made using a 1000µg/mL stock certified from AccuStandard or another source different from the QC. Solutions are stable for one week.
Created By Steph Kexel SOP No: 09-033-09 Date Initiated: 12/96 Revision Date: 1/15/16 Page 44 of 97 Stock Standard, 20.0mg/L N
AccuStandard Stock (NH4 and NO3 as N) 1mL of each DI water, q.s. 100mL
In a 100mL volumetric flask containing about 80mL of DI add 1mL each of stock - AccuStandard NH3-N and NO3 -N standards. Dilute to 100mL with DI and mix thoroughly. Record the information in the stock standard logbook.
Working Standard Solutions
mL(g) 20mg/L Stock mg/L N
10 2.0 5 1.0 3 0.6 1 0.2 0.05 0.1 0.025 0.05
Transfer aliquots of stock 20mg/L stock as noted above to individual 100mL volumetric flasks. Dilute to volume with DI water and mix thoroughly. Record the information in working standard logbook. Prepare fresh weekly.
Cadmium column efficiency is not tested for this analysis because the calibrants are digested in potassium persulfate. Ensure that column efficiency has been tested prior to this run on the most recent NOx analysis and has fallen within acceptable limits.
Sample Preparation
Sample turbidity is removed by filtration though a 47mm GF/F prior to analysis and will yield the TDN result. Turbidity absorbing in the range of 550 nanometers (nm) will present a positive bias.
Preserve the sample by freezing at -10°C or below until the time of analysis.
Sample containers are to be rinsed with 1:1 hydrochloric acid, followed by DI water and finally by an aliquot of the sample itself. Disposable sample tubes are used during analysis to avoid contamination from improper washing of glass tubes.
Pipette 10mL of sample into a 30mL test tube. 10mL of standards, QC and blanks should also be pipetted. The lowest concentration of standard is pipetted 6 times to allow for running the PQL throughout the run. The rest of the standards are pipetted at least 3 times for each concentration.
The quality control sample (QC) is made up in 100mL volumes per every 60 or so samples. Larger quantities are necessary if running large batches of samples. The QC concentration changes with each new lot number purchased from Environmental Resource Associates and is made fresh daily.
Generally, the sample is spiked with 250µL of the 20ppm stock standard, and are spiked directly into the test tube before digestion yielding a spike concentration of 0.488ppm.
Add 5mL of digestion reagent and mix thoroughly for a final volume of 15mL in the test tube. Place the samples and standards into the autoclave and heat from 235°F for one hour.
Created By Steph Kexel SOP No: 09-033-09 Date Initiated: 12/96 Revision Date: 1/15/16 Page 45 of 97
Allow the autoclave pressure to equalize, and the temperature to decrease removing the sample. Cool to room temperature overnight.
If analysis cannot be performed immediately samples can be stored at 4°C after digestion.
Instrumental Analysis
Transfer the samples to disposable test tubes for automated TDN analysis on the Lachat (method 31-107-04-4-A).
It is assumed that the user is basically familiar with the appearance and location of the various parts of the Lachat. It is also assumed that a method for running TDN analyses has already been created, and that the user is familiar with basic system operations. For a physical description of the instrument and any related software information, see the section entitled “The Lachat Quick Chem 8500”.
Ensure that the proper sized sample loop is connected between ports 1 and 4 of the inject valve.
The sample loop is 150cm long and labeled “TN”. It can be found in the drawer of Lachat parts.
The column efficiency should be greater than 90%. When the efficiency falls outside of this range, the cadmium column must be replaced.
Introduce the ammonium chloride reagent into the chemistry manifold first and let it flow for about a minute before introducing the sulfanilamide.
When using the cadmium column, ALWAYS ensure that the column is activated when ALL reagents are pumping through the system. Likewise, make sure the column is in the “off” position at the end of the run before taking reagent lines out of solution for the wash step.
Cadmium columns are purchased from Lachat instruments (CAT # 50237A), however cadmium may be regenerated in the laboratory according to Lachat publication WI#J20008. Publication will be made available upon request.
Calculations
• Percent recovery for the spike is determined using the following formula: − BA )( %R = x100 C
Where: A = measured value in mg/L for the sample + spike B = measured value in mg/L for the original sample C = concentration of the spike in mg/L
Created By Steph Kexel SOP No: 09-033-09 Date Initiated: 12/96 Revision Date: 1/15/16 Page 46 of 97 • Relative percent difference for the duplicate is calculated by the following formula: (A − B) RPD = x100 + [(A B)/ 2]
Where: A = the value in mg/L for the first run of the sample B = the value in mg/L for the second run of the sample
• To determine the column efficiency use the following formula: [NO- - N] E = 3 x100 NO- − N [ 2 ]
Where: E = column efficiency - NO3 -N = concentration of nitrate standard - NO2 -N = concentration of nitrite standard
Quality Control
A certified second source quality control sample (purchased from Fisher) is analyzed for every delivery group (or every 10 samples) and the value must be within 85-115% recovery to be acceptable.
A spike is analyzed for every delivery group (or every 10 samples). The percent recovery must fall within the 85-115% recovery to be acceptable.
A duplicate is analyzed for every delivery group (or every 10 samples). The relative percent difference for the duplicate analysis must fall below 20%.
A blank is analyzed for every delivery group or every 10 samples and the value must fall below the practical quantitation limit (PQL) to be considered acceptable. The concentration of the PQL is the low standard.
A second quality control sample is analyzed at the end of the run and is the concentration of the PQL, or the lowest standard. Acceptable ranges for the PQL are 50-150% recovery.
Other System Notes
Light interference filter: 520nm Sample Loop Size: 150cm
Created By Steph Kexel SOP No: 09-033-09 Date Initiated: 12/96 Revision Date: 1/15/16 Page 47 of 97 Total Dissolved Phosphorus EPA 365.1
Scope and Application
EPA Method 365.1 is the reference method for the measurement of total dissolved phosphorus (TDP) in seawater after preliminary digestion with sodium persulfate.
The Method Detection Limit (MDL) and Practical Quantitation Limit (PQL) for this analysis are determined yearly. For current MDL and PQL limits, see the chart entitled Method Detection Limit Determination.
This section provides a stepwise procedure for bench use by laboratory personnel.
This method (Lachat method number 31-115-01-1-H) was developed for the quantitative analysis of ortho-phosphate in water and seawater. The applicable range is 0 to 0.5mg/L of ortho-phosphate as phosphorus. Samples higher in range may be diluted and re-run or analyzed calibrating with a higher concentration (usually 1.0ppm).
This method is based on automated colorimetric determination and is restricted to the use by or under the supervision of analysts experienced in the use of auto analyzers.
Summary of Method
For total dissolved phosphorus, the whole water sample is filtered through a 0.7mm GF/F filter. The filtrate is then preserved by freezing at or below -10°C until it is time for preparation. The filtered sample will yield total dissolved phosphorus (TDP) values, while the whole water sample will yield total phosphorus (TP) values. Analysis is completed within 28 days of arrival at the laboratory.
The sample is digested with sodium persulfate in an autoclave at 235°F for one hour.
Samples for TDP are analyzed by an automated procedure on the Lachat flow analyzer. An aliquot of digested sample is reacted with reagents containing sulfuric acid, antimony tartrate, ammonium molybdate and ascorbic acid, and the resulting molybdenum blue complex is measured photometrically at 880nm.
This method is based on automated colorimetric determinations and is restricted to the use by, or under the supervision of, analysts experienced in the use of auto analyzer equipment.
The Lachat QuickChem is calibrated with a minimum of a six point curve (including the blank) at the time of analysis (purchased from AccuStandard). The calibration curve is then verified by an external quality control sample from Fisher, an independent supplier. Supplier guidelines are used for making up the quality control solutions, as well as for information on the true value and acceptable value range for the analytes being measured in each quality control sample.
This initial calibration check along with an initial calibration blank, demonstrate that the instrument is capable of acceptable performance at the beginning of the sample analysis. In order to ensure continuing acceptable performance a continuing calibration check and continuing calibration blank are run every tenth sample. For every 10 samples, a laboratory spike analysis and a laboratory duplicate analysis are performed. At the end of the run a practical quantitative limit (PQL) is run for further quality control verification.
Created By Steph Kexel SOP No: 09-033-09 Date Initiated: 12/96 Revision Date: 1/15/16 Page 48 of 97 Interferences
Arsenate is analyzed similarly to orthophosphate, and will cause interference if present. Reducing the arsenic acid to arsenious acid with sodium bisulfite should alleviate this problem. Sodium bisulfite treatment will also take care of any problems with high iron concentration (>50 mg/L).
Silica forms a pale blue complex that also absorbs at 880nm and is generally insignificant because a silica concentration of approximately 30mg/L would be required to produce a 0.005 P/L positive error in orthophosphate.
Acidity among samples, standards and blanks should be carefully controlled. Large variations in acidity will affect sample and/or standard peaks.
Good glassware cleaning procedures should always be used. Phosphorus contamination is a constant problem. Proper glassware washing protocol should eliminate this problem.
References
31-115-01-1-H, August 2003. Determination of Orthophosphate by Flow Injection Analysis. Lachat Instruments, Loveland, CO.
EPA Method 365.1. Determination of Phosphorus by Semi-Automated Colorimetry. Revision 2.0, August 1993. Environmental Monitoring Systems Laboratory, Office of Research and Development, U.S. Environmental Protection Agency, Cincinnati, Ohio.
Standard Method 4500-P A, B, G and H Phosphorous: Flow Injection Method. Page 4- 139 – 4-153, 20th Edition, 1998, Standard Methods for the Examination of Water and Wastewater.
Associated SOP’s
Refer to “SOP” titled “Hazardous Waste SOP” for proper waste disposal.
Refer to the notebook titled “SOP’s” located in the nutrients laboratory.
Safety
Samples are disposed in a hazardous waste jug and are appropriately labeled.
Reagents are hazardous and are made in the hood. Protective gear is worn when making reagents.
Ensure that waste lines from the Lachat are going to the proper hazardous waste jug located under the instrument.
Refer to the University of Connecticut’s Environmental Health and Safety chemical Health and safety web page at:
http://www.ehs.uconn.edu/ppp/index.php
A hard copy of the Chemical Hygiene Plan can be found on the notebook rack located on the lab bench. Also refer to the Hazardous Waste SOP.
Created By Steph Kexel SOP No: 09-033-09 Date Initiated: 12/96 Revision Date: 1/15/16 Page 49 of 97 Materials
Lachat QuickChem 8500 Market Forge Autoclave
Procedure
Reagent Preparation
Unless otherwise specified, all chemicals should be ACS grade or equivalent. DI water refers to high quality reagent water, TYPE I or TYPE II as defined in ASTM Standards, Part 31, D1193-74. When making reagents, date the container in which the reagent is stored, initial it, and write out the entire name of the reagent. Many of the following solutions are stable indefinitely. Otherwise, shelf life is noted.
• Stock Antimony Potassium Tartrate
We are currently using Fisher antimony potassium tartrate (catalog no. A867-250).
Antimony Potassium Tartrate 1.61g DI Water, q.s. 500mL final vol.
Dissolve 1.61 g of antimony potassium tartrate in about 400mL of DI water in 500mL volumetric flask. Dilute to 100mL with DI water and mix thoroughly. Store the solution in a dark plastic container. Solution is stable for one month.
• Stock Ammonium Molybdate
We are currently using Fisher ammonium molybdate (catalog no. A674-500).
Ammonium Molybdate 20g DI Water, q.s. 500mL final vol.
Fill amber poly bottle ¾ with DI water and add 20g of ammonium molybdate. Dilute to 500mL with DI water and mix thoroughly. Solution is stable for one month.
• Molybdate Color Reagent
We are currently using Fisher sulfuric acid (catalog no. SA176-4).
Stock Antimony Potassium Tartrate Solution 72mL Stock Ammonium Molybdate 213mL Sulfuric Acid 35mL DI Water, q.s. 1000mL final vol.
To a 1 liter volumetric flask add about 500mL of DI water, then 35mL of concentrated sulfuric acid. Swirl to mix. Add 213mL of stock ammonium molybdate solution and 72mL of stock antimony potassium tartrate solution. Dilute to 1000mL with DI water and mix thoroughly. Degas with helium for at least 5 minutes. Store in a dark plastic container. This solution is stable for one month.
Created By Steph Kexel SOP No: 09-033-09 Date Initiated: 12/96 Revision Date: 1/15/16 Page 50 of 97 • Ascorbic Acid
We are currently using Fisher, L-ascorbic acid (catalog no. BP351-500) and Fisher SDS (catalog no. BP166-100).
Ascorbic Acid 60g SDS 1g DI Water, q.s. 1000mL final vol
In a 1L volumetric add 60g of ascorbic acid in approximately 800mL DI water. Dilute to 1000 mL with DI water and mix thoroughly. Degas for a minimum of 5 minutes. Pour into clear plastic bottle and add 1g of SDS and swirl gently. This solution is stable for 5 days. Store the solution in a clear poly container.
• Digestion Reagent -- Sodium Persulfate
We are currently using Fisher sodium persulfate (catalog no.AC20202-0010) and Fisher sulfuric acid (catalog no. SA176-4).
Sulfuric Acid 11.4mL Sodium Persulfate 50g DI Water, q.s. 1000mL final vol.
Add 11.4mL sulfuric acid in a 1L clear small mouthed poly bottle and cool under tap water. Dissolve 50g of sodium persulfate and dilute to final volume of 1000mL with DI. The solution is not stable and should be made immediately prior to use.
Standard Preparation
Working standards can be made by weight or volume. Standards are made using a 1000µg/mL stock certified from AccuStandard or another source different from the QC and are made fresh weekly.
Stock Standard, 10.0mg/L N
AccuStandard Stock (Phosphorous) 1mL DI water, q.s. 100mL
In a 100mL volumetric flask containing about 80mL of DI add 1mL of stock AccuStandard phosphorus standard. Dilute to 100mL with DI and mix thoroughly. Record the information in the stock standard logbook.
Working Standard Solutions
mL(g) 10mg/L Stock mg/L P
5.0 0.500 3.0 0.300 1.0 0.100 0.5 0.050 0.25 0.025 0.1 0.010
Created By Steph Kexel SOP No: 09-033-09 Date Initiated: 12/96 Revision Date: 1/15/16 Page 51 of 97 Transfer aliquots of stock 10mg/L stock as noted above to individual 100mL volumetric flasks. Dilute to volume with DI water and mix thoroughly. Record the information in working standard logbook. Prepare fresh weekly.
Sample Preparation
Sample turbidity is removed by filtration though a 47mm GF/F prior to analysis. Turbidity absorbing in the range of 880 nanometers (nm) will present a positive bias. The analyzed filtrate will yield a total dissolved phosphorus (TDP) result.
The sample is then preserved by freezing at or below -10°C until analysis is performed.
Sample containers are to be rinsed with 1:1 hydrochloric acid, followed by DI water and finally by an aliquot of the sample itself.
Pipette 10mL of sample into a 30mL test tube. 10mL of standards, QC and blanks should also be pipetted. The lowest concentration of standard is pipetted 6 times to allow for the analysis of PQL (Project Quantitative Limit) throughout the run. The rest of the standards are pipetted at least 3 times for each concentration.
The quality control sample (QC) is made up in 100mL volumes per every 60 or so samples. Larger quantities are necessary if running large batches of samples. The QC concentration changes with each new lot # purchased from Environmental Resource Associates (Catalog no. 525).
Generally, spiked samples are spiked with 250µL of the 10ppm stock standard, and are spiked directly into the test tube before digestion yielding a spike concentration of 0.244ppm.
To each test tube add 3mL of digestion reagent and mix thoroughly. Place the samples, QC and standards into the autoclave and heat from 235°F.
Allow the autoclave pressure to equalize, and the temperature to decrease removing the sample. Cool to room temperature overnight.
If analysis cannot be performed immediately samples can be stored at 4°C after digestion.
Transfer the samples to disposable glass test tubes for automated ortho-phosphate analysis on the Lachat.
Instrumental Analysis
Analyze the sample for TDP using Lachat method for phosphate in water and seawater (method 31-115-01-1-H).
It is assumed that the user is basically familiar with the appearance and location of the various parts of the Lachat. It is also assumed that a method for running TDP analyses has already been created, and that the user is familiar with basic system operations. For a physical description of the instrument and any related software information, see the section entitled “The Lachat Quick Chem 8500”.
Ensure that pump tubing is pumping all reagents and proper sample loop is connected.
Ensure that the sample line from the auto-sampler is connected to port 6 of the valve.
Created By Steph Kexel SOP No: 09-033-09 Date Initiated: 12/96 Revision Date: 1/15/16 Page 52 of 97 Ensure that a method is selected that utilizes the refractive index correction as all TDP samples have the refractive index dip at the start of the peak. This correction eliminates any issues that would be seen with integration.
Calculations
• Percent recovery for the spike is determined using the following formula: (A − B) %R = x100 C
Where: A = measured value in mg/L for the sample + spike B = measured value in mg/L for the original sample C = concentration of the spike in mg/L
• Relative percent difference for the duplicate is calculated by the following formula: (A − B) RPD = x100 + [(A B)/ 2]
Where: A = the value in mg/L for the first run of the sample B = the value in mg/L for the second run of the sample
Quality Control
A certified second source quality control sample (purchased from Fisher) is analyzed for every delivery group (or every 10 samples) and the value must be within 85-115% recovery to be acceptable.
A spike is analyzed for every delivery group (or every 10 samples). The percent recovery must fall within the 85-115% recovery to be considered acceptable.
A duplicate is analyzed for every delivery group (or every 10 samples) and must have a relative percent difference below 20%.
A blank is analyzed for every delivery group or every 10 samples and the value must fall below the practical quantitation limit (PQL) to be considered acceptable. The concentration of the PQL is the low standard.
A second quality control sample is analyzed at the end of the run and is the concentration of the PQL, or the lowest standard. Acceptable ranges for the PQL are 50-150% recovery.
Other System Notes
Chemistry channel 2 Sample loop 150cm Light interference filter: 880nm Special instructions: The reaction module for phosphorus determinations comes equipped with a heating coil that heats the sample stream (after the addition of the reagents) to 37°C, which promotes better color development. This coil should be given 15 minutes to warm up before any samples are run.
Created By Steph Kexel SOP No: 09-033-09 Date Initiated: 12/96 Revision Date: 1/15/16 Page 53 of 97 Dissolved Silica EPA 370.1
Scope and Application
EPA Method 370.1 is the reference method for measuring dissolved silica in seawater by automated colorimetric determination. This section provides a stepwise procedure for bench use by laboratory personnel.
This method (Lachat silica method number 10-114-27-1-B) was developed for the quantitative analysis of silica in seawater. The applicable range is 0 to 5mg/L. Samples higher than the calibration range must be diluted and re-run or the instrument may be recalibrated with higher concentration standards.
This method is based on automated colorimetric determination and is restricted to the use by or under the supervision of analysts experienced in the use of auto analyzers as a quantitative tool.
Summary of Method
For dissolved silica analysis, the whole water sample is filtered through a polycarbonate 47mm, 0.4µm membrane filter in the field. The filtrate is then refrigerated at 4°C (do not freeze) until analysis can be completed. Analysis is completed within 28 days from arrival date at the laboratory.
Samples for dissolved silica are analyzed by an automated procedure, on Lachat QuickChem 8500 flow analyzer, and is based on the reduction of silicomolybdate in acidic solution to molybdenum blue by ascorbic acid. Oxalic acid is introduced to the sample stream before the addition of ascorbic acid to minimize interference from phosphates and is measured at 820 nm.
The Lachat Auto Analyzer is calibrated with a minimum of a six point curve (including the blank) at the time of analysis (purchased from AccuStandard). The calibration curve is then verified by an external quality control sample from an independent supplier. Supplier guidelines are used for making up the quality control solutions, as well as for information on the true value and acceptable value range for the analytes being measured in each quality control sample.
An initial calibration check along with an initial calibration blank, demonstrate that the instrument is capable of acceptable performance at the beginning of the sample analysis. In order to ensure continuing acceptable performance a continuing calibration check and continuing calibration blank are run every tenth sample. For every 10 samples, a laboratory spike analysis and a laboratory duplicate analysis are performed. At the end of the run a practical quantitative limit (PQL) is run for further quality control verification.
The Method Detection Limit (MDL) and Practical Quantitation Limit (PQL) for this analysis are determined yearly. For current MDL and PQL limits, see the chart entitled Method Detection Limit Determination.
This method is based on automated colorimetric determinations and is restricted to the use by, or under the supervision of, analysts experienced in the use of auto analyzer equipment.
Created By Steph Kexel SOP No: 09-033-09 Date Initiated: 12/96 Revision Date: 1/15/16 Page 54 of 97 Interferences
Silica contamination is likely to occur if reagents, standards or samples are stored in glass. Keep the use of glass to a minimum, and do not use glass for storage. Use plastic auto analyzer cups on the Lachat.
Phosphate interference is reduced by the addition of oxalic acid.
Tannin and large amounts of sulfides or iron can cause interference. Remove sulfides by acidifying, then boiling the samples. Disodium EDTA will take care of iron interference. This is not typically performed on LISS samples.
References
10-114-27-1-B, October 30, 2007. Determination of Silicate by Flow Injection Analysis. Lachat Instruments, Loveland, Colorado.
EPA Method 370.1. Editorial Revision 1978. Silica, Dissolved (Colorimetric). U.S. Environmental Protection Agency
Associated SOP’s
Refer to “SOP” titled “Hazardous Waste SOP” for proper waste disposal.
Refer to the notebook titled “SOP’s” located in the nutrients laboratory.
Safety
Reagents are hazardous and are made in the hood. Protective gear is worn when making reagents.
Ensure that waste lines from the Lachat are going to the proper hazardous waste jug located under the instrument.
Refer to the University of Connecticut’s Environmental Health and Safety chemical health and safety web page at:
http://www.ehs.uconn.edu/ppp/index.php
A hard copy of the Chemical Hygiene Plan can be found on the notebook rack located on the lab bench. Also refer to the Hazardous Waste SOP.
Materials
Lachat QuickChem 8500 Analyzer
Created By Steph Kexel SOP No: 09-033-09 Date Initiated: 12/96 Revision Date: 1/15/16 Page 55 of 97 Procedure
Reagent Preparation
Unless otherwise specified, all chemicals should be ACS grade or equivalent. DI water refers to high quality reagent water, TYPE I or TYPE II as defined in ASTM Standards, Part 31, D1193-74. When making reagents, date the container in which the reagent is stored, initial it, and write out the entire name of the reagent. Many of the following solutions are stable indefinitely. Otherwise, shelf life is noted.
• Molybdate Reagent
We are currently using Fisher ammonium molybdate (catalog no. A674-500) and Fisher sulfuric acid (catalog no. SA176-4).
Ammonium Molybdate Tetrahydrate 40g Sulfuric Acid 16mL DI Water, q.s. 1000mL final vol.
Fill volumetric flask with about 600mL of DI water and add 16mL of sulfuric acid. Cool under tap water, being careful not to introduce the tap water into the volumetric flask. Add 40g ammonium molybdate and dilute to final volume. Degas for a minimum of 5 minutes with helium. If a blue color or precipitate develops, discard the solution. Store the solution in a dark plastic container. The solution is stable for one month.
• Oxalic Acid Reagent
We are currently using Fisher oxalic acid dihydrate (catalog no. A219-500).
Oxalic Acid 50g DI Water, q.s. 500mL final vol.
Dissolve 50g of oxalic acid in 500mL of DI water and stir to mix, about 30 to 60 minutes. Degas with helium for at least 5 minutes. Store the solution in a clear plastic container. Solution is stable for 1 week.
• Tin Chloride
We are currently using Fisher tin (II) chloride dihydrate (catalog no. T142-100) and hydroxylamine hydrochloride (catalong no. H330-100) and sulfuric acid (catalog no. SA176- 4).
Sulfuric Acid 11mL Hydroxylamine Hydrochloride 1g Tin (II) Chloride 0.15g DI Water, q.s. 500mL final vol.
In a 500mL class A volumetric flask, add 250mL DI water, then slowly add 11mL sulfuric acid, 1g hydroxylamine hydrochloride, and tin (II) chloride dilute to volume and mix. Degas for a minimum of 5 minutes. Store the solution in a clear plastic container and is stable for one week.
Created By Steph Kexel SOP No: 09-033-09 Date Initiated: 12/96 Revision Date: 1/15/16 Page 56 of 97 Standard Preparation
Working standards can be made by weight or volume. Standards are made using a 1000µg/mL stock certified from AccuStandard or another source different from the QC. Discard weekly.
Stock Standard, 10.0mg/L N
AccuStandard Stock (Silica SiO2) 2mL DI water, q.s. 200mL
In a 100mL plastic volumetric flask containing about 80mL of DI add 1mL of stock AccuStandard silica standard. Dilute to 100mL with DI and mix thoroughly. Record the information in the stock standard logbook. Make sure that plastic volumetric flasks are used to prepare all standards and quality controls. There is not a plastic volumetric flask in the 200mL volume, so prepare the stock in duplicate aliquots and mix together.
Working Standard Solutions
mL(g) 10mg/L Stock mg/L SiO2
50 5.0 30 3.0 10 1.0 5 0.5 3 0.3 1 0.1 0.5 0.05
Transfer aliquots of stock 10mg/L stock as noted above to individual 100mL volumetric flasks. Dilute to volume with DI water and mix thoroughly. Record the information in working standard logbook. Prepare fresh weekly.
Sample Preparation
Sample turbidity is removed by filtration though a 47mm, 0.4µm polycarbonate membrane filter prior to analysis. Turbidity absorbing in the range of 820 nanometers (nm) will present a positive bias. When filtered sample is analyzed, the dissolved silica result is reported. Dissolved silica values are reported and the filter is analyzed for biogenic silica.
Preserve the sample by refrigerating at 4°C until the time of analysis.
Ensure that samples are brought to room temperature before analysis.
Generally, 6mL of sample is spiked with 0.015mL of the 1000µg/mL stock standard, yielding a spike concentration of 2.49ppm.
The quality control sample (QC) is made up in 100mL volumes per every 60 or so samples. Larger quantities are necessary if running large batches of samples. Make the QC in a plastic volumetric flask. Generally, the QC concentration is 3.0ppm.
Sample containers are to be rinsed with 1:1 hydrochloric acid, followed by DI water and finally by an aliquot of the sample itself. Disposable plastic sample tubes are used during analysis to avoid contamination from improper washing of glass tubes.
Created By Steph Kexel SOP No: 09-033-09 Date Initiated: 12/96 Revision Date: 1/15/16 Page 57 of 97 Instrumental Analysis
It is assumed that the user is basically familiar with the appearance and location of the various parts of the Lachat QuickChem AutoAnalyzer. It is also assumed that a method for running silica analyses has already been created, and that the user is familiar with basic system operations. For a physical description of the instrument and any related software information, see the section entitled “The Lachat Quick Chem 8500”.
The silica manifold shares the number 2 channel with ortho-phosphorus and must be installed prior to analysis. It is located in the drawer next to the computer. Ensure that the wavelength filter and heating coil are hooked up to the manifold with the proper sample loop.
Allow the manifold heater to come to temperature before starting analysis.
Check for leaks while pumping rinse water through the manifold. It is common after switching manifolds to have leaking at various fittings. It is crucial to ensure that the leaking has been addressed before moving on to running samples.
Refer to the Lachat SOP for calibrating and setting up the sample run.
Calculations
• Percent recovery for the spike is determined using the following formula: (A − B) %R = x100 C
Where: A = measured value in mg/L for the sample + spike B = measured value in mg/L for the original sample C = concentration of the spike in mg/L
• Relative percent difference for the duplicate is calculated by the following formula: (A − B) RPD = x100 + [(A B)/ 2]
Where: A = the value in mg/L for the first run of the sample B = the value in mg/L for the second run of the sample
Quality Control
A certified second source quality control sample (purchased from Fisher) is analyzed for every delivery group (or every 10 samples) and the value must be within 85-115% recovery to be acceptable.
A spike is analyzed for every delivery group (or every 10 samples). The percent recovery must fall within the 85-115% recovery to be acceptable.
A duplicate sample is analyzed for every delivery group (or every 10 samples). The relative percent difference (RPD) must be below 20%.
Created By Steph Kexel SOP No: 09-033-09 Date Initiated: 12/96 Revision Date: 1/15/16 Page 58 of 97 A blank is analyzed every delivery group or every 10 samples and the value must fall below the practical quantitation limit (PQL) to be considered acceptable. The concentration of the PQL is the low standard.
A second quality control sample is analyzed at the end of the run and is the concentration of the PQL, or the lowest standard. Acceptable ranges for the PQL are 50-150 % recovery.
Other System Notes
Sample Loop: 150cm Light interference filter: 820nm Heater Loop: 175cm
Created By Steph Kexel SOP No: 09-033-09 Date Initiated: 12/96 Revision Date: 1/15/16 Page 59 of 97 Biogenic Silica EPA 370.1
Scope and Application
The method for the determination of biogenic silica is a polycarbonate membrane filter pad that is digested first with sodium hydroxide and then followed by sulfuric acid neutralization. The digested sample is then analyzed for silica by an automated colorimetric procedure. This section provides a stepwise procedure for bench use by laboratory personnel.
EPA method 370.1 is the reference method for measuring total and dissolved silica in water and seawater by automated colorimetric determination. This section provides a stepwise procedure for bench use by laboratory personnel.
This method (Lachat silica method number 10-114-27-1-B) was developed for the quantitative analysis of silica in water and seawater. The applicable range is 0 to 5mg/L. Samples higher than the calibration range must be diluted and re-run or the instrument may be recalibrated with higher concentration standards.
This method is based on automated colorimetric determination and is restricted to the use by or under the supervision of analysts experienced in the use of auto analyzers as a quantitative tool.
Summary of Method
A known volume of whole water is passed though a 47mm, 0.4µm polycarbonate membrane filter and placed in a plastic centrifuge tube in the field. The filter is frozen until ready for analysis. The digestion of the filter pad is performed within 28 days of arrival at the laboratory. 0.2M sodium hydroxide solution is added to the centrifuge tube with filter. The tube and filter are then heated in a pressure cooker for 15 minutes. The sample is then neutralized with 0.5M sulfuric acid and diluted to a final volume of 50mL with DI water. The sample is then ready for analysis by the silica method on the Lachat.
Samples for biogenic silica are analyzed by an automated procedure, on the Lachat QuickChem 8500 flow analyzer, whereby silica reacts with molybdate reagent in acid media to form a yellow silicomolybdate complex which is measured at 820 nm.
The Lachat Auto Analyzer is calibrated with a minimum of a six point curve (including the blank) at the time of analysis (purchased from AccuStandard). The calibration curve is then verified by an external quality control sample from an independent supplier. Supplier guidelines are used for making up the quality control solutions, as well as for information on the true value and acceptable value range for the analytes being measured in each quality control sample.
An initial calibration check along with an initial calibration blank, demonstrate that the instrument is capable of acceptable performance at the beginning of the sample analysis. In order to ensure continuing acceptable performance a continuing calibration check and continuing calibration blank are run every tenth sample. For every 10 samples, a laboratory spike analysis and a laboratory duplicate analysis are performed. At the end of the run a PQL (Practical Quantitation Limit) is run for further quality control verification.
The Method Detection Limit (MDL) and Practical Quantitation Limit (PQL) for this analysis are determined yearly. For current MDL and PQL limits, see the chart entitled Method Detection Limit Determination.
Created By Steph Kexel SOP No: 09-033-09 Date Initiated: 12/96 Revision Date: 1/15/16 Page 60 of 97 This method is based on automated colorimetric determinations and is restricted to the use by, or under the supervision of, analysts experienced in the use of auto analyzer equipment.
Interferences
Silica contamination is likely to occur if reagents, standards or samples are stored in glass. Keep the use of glass to a minimum, and do not use glass for storage.
Phosphate interference is reduced by the addition of oxalic acid.
Tannin and large amounts of sulfides or iron can cause interference. Remove sulfides by acidifying, then boiling the samples. Disodium EDTA will take care of iron interference.
References
10-114-27-1-B, October 30, 2007. Determination of Silicate by Flow Injection Analysis. Lachat Instruments, Loveland, Colorado.
EPA Method 370.1. Editorial Revision 1978. Silica, Dissolved (Colorimetric). U.S. Environmental Protection Agency
Associated SOP’s
Refer to “SOP” titled “Hazardous Waste SOP” for proper waste disposal.
Refer to the notebook titled “SOP’s” located in the nutrients laboratory.
Safety
Reagents are hazardous and are made in the hood. Protective gear is worn when making reagents.
Ensure that waste lines from the Lachat are going to the proper hazardous waste jug located under the instrument.
Refer to the University of Connecticut’s Environmental Health and Safety Chemical Health and Safety web page at:
http://www.ehs.uconn.edu/ppp/index.php
A hard copy of the Chemical Hygiene Plan can be found on the notebook rack located on the lab bench. Also refer to the Hazardous Waste SOP.
Materials
Lachat QuickChem 8500 Auto Analyzer Pressure cooker Hot Plate
Created By Steph Kexel SOP No: 09-033-09 Date Initiated: 12/96 Revision Date: 1/15/16 Page 61 of 97 Procedure
Reagent Preparation
Unless otherwise specified, all chemicals should be ACS grade or equivalent. DI water refers to high quality reagent water, TYPE I or TYPE II as defined in ASTM Standards, Part 31, D1193-74. When making reagents, date the container in which the reagent is stored, initial it, and write out the entire name of the reagent. Many of the following solutions are stable indefinitely. Otherwise, shelf life is noted.
• Molybdate Reagent
We are currently using Fisher ammonium molybdate ( catalog no. A674-500) and Fisher sulfuric acid (catalog no. SA176-4).
Ammonium Molybdate Tetrahydrate 40g Sulfuric Acid 16mL DI Water, q.s. 1000mL final vol.
Fill volumetric flask with about 600mL of DI water and add 16mL of sulfuric acid. Cool under tap water, being careful not to introduce the tap water into the volumetric flask. Add 40g ammonium molybdate and dilute to final volume. Degas for a minimum of 5 minutes with helium. If a blue color or precipitate develops, discard the solution. Store the solution in a dark plastic container. The solution is stable for one month.
• Oxalic Acid Reagent
We are currently using Fisher oxalic acid dihydrate (catalog no. A219-500).
Oxalic Acid 50g DI Water, q.s. 500mL final vol.
Dissolve 50g of oxalic acid in 1000mL of DI water and stir to mix, about 30 to 60 minutes. Degas with helium for at least 5 minutes. Store the solution in a clear plastic container. Solution is stable for 1 week.
• Tin Chloride
We are currently using Fisher tin (II) chloride dihydrate (catalog no. T142-100) and hydroxylamine hydrochloride (catalong no. H330-100) and sulfuric acid (catalog no. SA176- 4).
Sulfuric Acid 11mL Hydroxylamine Hydrochloride 1g Tin (II) Chloride 0.15g DI Water, q.s. 500mL final vol.
In a 1L class A volumetric flask, add 900mL DI water, then slowly add 50g L- ascorbic acid, dilute to volume and mix. The solution is stable for one week.
• 1N Sulfuric Acid
We are currently using Fisher sulfuric acid (catalog no. SA176-4),
Sulfuric Acid 28mL DI Water, q.s. 1000mL final vol.
Created By Steph Kexel SOP No: 09-033-09 Date Initiated: 12/96 Revision Date: 1/15/16 Page 62 of 97
In a 500mL class A volumetric flask, add 250mL DI water, then slowly add 11mL sulfuric acid, 1g hydroxylamine hydrochloride, and tin (II) chloride dilute to volume and mix. Degas for a minimum of 5 minutes. Store the solution in a clear plastic container. Solution is stable indefinitely.
Digestion Reagents:
• 0.2M Sodium Hydroxide
Sodium Hydroxide 8g DI Water, q.s. 1000mL final vol.
Fill a 1 L clear small mouth plastic poly bottle with 1000mL of DI water and add 8g of sodium hydroxide. Make prior to use.
• 0.5M Sulfuric Acid
Sulfuric Acid 14mL DI Water, q.s. 1000mL final vol.
Fill a 1L clear small mouth plastic poly bottle with 1000mL of DI water and add 14mL of sulfuric acid. Make prior to use.
Standard Preparation
Working standards can be made by weight or volume. Standards are made using a 1000µg/mL stock certified from AccuStandard or another source different from the QC. Solutions are stable for one week.
Stock Standard, 10.0mg/L N
AccuStandard Stock (Silica) 2mL DI Water, q.s. 200mL
In a 100mL plastic volumetric flask containing about 80mL of DI add 1mL of stock AccuStandard silica standard. Dilute to 100mL with DI and mix thoroughly. Record the information in the stock standard logbook. Make sure that plastic volumetric flasks are used to prepare all standards and quality controls. There is not a plastic volumetric flask in the 200mL volume, so prepare the stock in duplicate aliquots and mix together.
Working Standard Solutions
mL(g) 10mg/L Stock mg/L SiO2
50 5.0 30 3.0 10 1.0 5 0.5 3 0.3 1 0.1 0.5 0.05
Created By Steph Kexel SOP No: 09-033-09 Date Initiated: 12/96 Revision Date: 1/15/16 Page 63 of 97 Transfer aliquots of stock 10mg/L stock as noted above to individual 100mL volumetric flasks. Dilute to volume with DI water and mix thoroughly. Record the information in working standard logbook. Prepare fresh weekly.
Sample Preparation
Preserve the sample by freezing at or below -10°C until the time of analysis.
Clean, sterilized blue capped preparation tubes are purchased from Fisher Scientific (cat #010-500-263) and provided to CT DEEP to collect the filter. One filter is placed in the tube and stored in the freezer prior to analysis.
Ensure that samples are brought to room temperature before analysis.
Generally, 8mL of sample is spiked with 0.075mL of the 1000µg/mL stock standard, yielding a spike concentration of 9.27ppm.
The quality control sample (QC) is made up in 100mL volumes per every 60 or so samples. Larger quantities are necessary if running large batches of samples. Make the QC in a plastic volumetric flask. Generally, the QC concentration is 3.0ppm.
Sample Digestion
Line up blue capped, sample tubes in sample rack with corners cut off (green) so they will fit in the pressure cooker.
Set pressure cooker on hot plate, set on high with about 1-2 inches of tap water in the bottom. Wait until water is boiling before adding samples.
Add 8mL of the first digestion reagent (0.2M sodium hydroxide) and make sure that the filter is submerged.
Place one tray at a time in pressure cooker for 15 minutes.
Add 40mL of DI water to boiled samples using a plastic small mouth bottle and dispensette pipette.
Add 2mL of 0.5M sulfuric acid
Invert three times and let samples sit overnight before analyzing the next day.
ALWAYS USE PLASTIC FOR EVERYTHING (IE. SAMPLE CUPS, QC VOLUMETRIC FLASK AND REAGENTS)!!
Instrumental Analysis
It is assumed that the user is basically familiar with the appearance and location of the various parts of the Lachat QuickChem AutoAnalyzer. It is also assumed that a method for running silica analyses has already been created, and that the user is familiar with basic system operations. For a physical description of the instrument and any related software information, see the section entitled “The Lachat Quick Chem 8500”.
The silica manifold shares the number 2 channel with ortho-phosphorus and must be installed prior to analysis. It is located in the drawer under the hood. Ensure that the wavelength filter and heating coil are hooked up to the manifold with the proper sample loop.
Created By Steph Kexel SOP No: 09-033-09 Date Initiated: 12/96 Revision Date: 1/15/16 Page 64 of 97
Allow the manifold heater to come to temperature before starting analysis.
Check for leaks while pumping rinse water through the manifold. It is common after switching manifolds to have leaking at various fittings. It is crucial to ensure that the leaking has been addressed before moving on to running samples.
The same QC is used for both the biogenic silica and the dissolved silica.
The same calibration is used when running both dissolved and biogenic silica and the samples may be run at the same time.
Refer to the Lachat SOP for calibrating and setting up the sample run.
Calculations
• Percent recovery for the spike is determined using the following formula: (A − B) %R = x100 C
Where: A = measured value in mg/L for the sample + spike B = measured value in mg/L for the original sample C = concentration of the spike in mg/L
• Relative percent difference for the duplicate is calculated by the following formula: (A − B) RPD = x100 + [(A B)/ 2]
Where: A = the value in mg/L for the first run of the sample B = the value in mg/L for the second run of the sample
• Biogenic Silica is calculated by the following formula: (A* B) BioSiO2(mg / L) = VolumeFiltered(L)
Where: A = instrument reading (mg/L) B = volume extracted (L)
Created By Steph Kexel SOP No: 09-033-09 Date Initiated: 12/96 Revision Date: 1/15/16 Page 65 of 97 Quality Control
A certified second source quality control sample (purchased from Fisher) is analyzed for every delivery group (or every 10 samples) and the value must be within 85-115% recovery to be considered acceptable.
A spike is analyzed for every delivery group (or every 10 samples). The percent recovery must fall within the 85-115% recovery to be acceptable.
A duplicate sample is analyzed for every delivery group (or every 10 samples). The relative percent difference (RPD) must be below 20%.
A blank is analyzed every delivery group or every 10 samples and the value must fall below the practical quantitation limit (PQL) to be considered acceptable. The concentration of the PQL is the low standard.
A second quality control sample is analyzed at the end of the run and is the concentration of the PQL, or the lowest standard. Acceptable ranges for the PQL are 50-150% recovery.
Other System Notes
Sample Loop: 150cm Light interference filter: 820nm Heater Loop: 175cm
Created By Steph Kexel SOP No: 09-033-09 Date Initiated: 12/96 Revision Date: 1/15/16 Page 66 of 97 Particulate Phosphorus EPA 365.1
Scope and Application
Aspila et al., 1976, is the reference method for acid extraction of particulate phosphorus deposited on filters. Ortho-phosphorus is the sole P product of the extraction and is determined by an automated colorimetric procedure. This section provides a stepwise procedure for bench use by laboratory personnel.
The Method Detection Limit (MDL) and Practical Quantitation Limit (PQL) for this analysis are determined yearly. For current MDL and PQL limits, see the chart entitled Method Detection Limit Determination.
A known volume of whole water is passed through two 47mm GF/F filters in the field. The filters are frozen until ready for analysis within 28 days. When ready, they are dried in a drying oven for one hour at 105°C and muffled at 500°C in a muffle furnace for one hour. The filters are placed in a screw cap test tube and extracted with 30mL of 1N hydrochloric acid, capped and inverted repeatedly. The sample is filtered before analysis with a syringe and 0.45µm sterile filter into auto analyzer cups. The sample is then ready for analysis by the ortho-phosphate method on the Lachat.
For every 10 samples, a blank, a laboratory spike analysis and a laboratory duplicate analysis are performed.
The analysis depends on the formation of a phosphomolybdenum blue complex, which is read colorimetrically at 880nm.
- - Phosphomolybdate Complex: 12MoO3 + H2PO4 → (H2PMo12O40)
This method is based on automated colorimetric determinations and is restricted to the use by, or under the supervision of, analysts experienced in the use of auto analyzer equipment.
The Lachat Analyzer is calibrated with a minimum of a six point curve (including the blank) at the time of analysis (purchased from AccuStandard). The calibration curve is then verified by an external quality control sample purchased from Fisher (Ricca Cat # 5839.1-16). Supplier guidelines are used for making up the quality control solutions, as well as for information on the true value and acceptable value range for the analytes being measured in each quality control sample.
An initial calibration check along with an initial calibration blank, demonstrate that the instrument is capable of acceptable performance at the beginning of the sample analysis. In order to ensure continuing acceptable performance a continuing calibration check and continuing calibration blank are run every tenth sample. For every 10 samples, a laboratory spike analysis and a laboratory duplicate analysis are performed. At the end of the run a PQL (Practical Quantitation Limit) is run for further quality control verification.
Interferences
Arsenate is analyzed similarly to ortho-phosphate, and will cause interference if present. Reducing the arsenic acid to arsenious acid with sodium bisulfite should alleviate this problem. Sodium bisulfite treatment will also take care of any problems with high iron concentration (>50mg/L).
Created By Steph Kexel SOP No: 09-033-09 Date Initiated: 12/96 Revision Date: 1/15/16 Page 67 of 97 Any silica present will react with the reagents in this method, forming a pale blue complex which also absorbs at 880nm. Because the method is very sensitive to small amounts of phosphorus, sensitivity to silica is also high. A silica concentration of approximately 30mg/L would be required to produce a 0.005mgP/L positive error of ortho-phosphate. Samples containing higher than this concentration of silica would need to be addressed.
Glass should be avoided if possible. Reagents should be made and stored in plastic. Naturally occurring silica in samples may be discriminated against by using an alternate color reagent recipe, given below, although this is not standard procedure.
Acidity among samples, standards and blanks should be carefully controlled. Large variations in acidity will affect sample and/or standard peaks.
Good glassware cleaning procedures should always be used. Phosphorus contamination is a constant problem. Proper glassware washing protocol should elevate this problem.
References
31-115-01-1-H, August 2003. Determination of Orthophosphate by Flow Injection Analysis. Lachat Instruments, Loveland, CO. EPA Method 365.1. Determination of Phosphorus by Semi-Automated Colorimetry. Revision 2.0, August 1993. Environmental Monitoring Systems Laboratory, Office of Research and Development, U.S. Environmental Protection Agency, Cincinnati, Ohio.
Standard Method 4500-P A, B, G and H Phosphorous: Flow Injection Method. Page 4- 139 – 4-153, 20th Edition, 1998, Standard Methods for the Examination of Water and Wastewater.
Associated SOP’s
Refer to “SOP” titled “Hazardous Waste SOP” for proper waste disposal.
Refer to the notebook titled “SOP’s” located in the nutrients laboratory.
Safety
Samples are disposed in hazardous waste jugs that are properly labeled.
Reagents are hazardous and are made in the hood. Protective gear is worn when making reagents.
Ensure that waste lines from the Lachat are going to the proper hazardous waste jug located under the instrument.
Refer to the University of Connecticut’s Environmental Health and Safety Chemical Health and Safety web page at:
http://www.ehs.uconn.edu/ppp/index.php
A hard copy of the Chemical Hygiene Plan can be found on the notebook rack located on the lab bench. Also refer to the Hazardous Waste SOP.
Created By Steph Kexel SOP No: 09-033-09 Date Initiated: 12/96 Revision Date: 1/15/16 Page 68 of 97 Materials
Drying Oven (Fisher model 750G) Muffle Furnace (Lindberg type 51828) Lachat QuickChem 8500 Analyzer
Procedure
Reagent Preparation
Unless otherwise specified, all chemicals should be ACS grade or equivalent. DI water refers to high quality reagent water, TYPE I or TYPE II as defined in ASTM Standards, Part 31, D1193-74. When making reagents, date the container in which the reagent is stored, initial it, and write out the entire name of the reagent. Many of the following solutions are stable indefinitely. Otherwise, shelf life is noted.
• Stock Antimony Potassium Tartrate
We are currently using Fisher antimony potassium tartrate (catalog no. A867-250).
Antimony Potassium Tartrate 1.61g DI Water, q.s. 500mL final volume
Dissolve 1.61 g of antimony potassium tartrate in about 400mL of DI water in 500mL volumetric flask. Dilute to 100mL with DI water and mix thoroughly. Store the solution in a dark plastic container. Solution is stable for one month.
• Stock Ammonium Molybdate
We are currently using Fisher ammonium molybdate (catalog no. A674-500).
Ammonium Molybdate 20g DI Water, q.s. 500mL final volume
Fill amber poly bottle ¾ with DI water and add 20g of ammonium molybdate. Dilute to 500mL with DI water and mix thoroughly. Solution is stable for one month.
• Molybdate Color Reagent—PP version.
This reagent differs slightly from the other ortho-phosphate reagent recipe. Because the samples are acidic, omit the sulfuric acid from this reagent.
Stock Antimony Potassium Tartrate Solution 72mL Stock Ammonium Molybdate 213mL DI Water, q.s. 1000mL final volume
To a 1 liter volumetric flask add about 500mL of DI water, then add 213mL of stock ammonium molybdate solution and 72mL of stock antimony potassium tartrate solution. Dilute to 1000mL with DI water and mix thoroughly. Degas with helium for at least 5 minutes. Store in a dark plastic container. This solution is stable for one month.
Created By Steph Kexel SOP No: 09-033-09 Date Initiated: 12/96 Revision Date: 1/15/16 Page 69 of 97 • Ascorbic Acid
We are currently using Fisher, L-ascorbic acid (catalog no. BP351-500) and Fisher SDS (catalog no. BP166-100).
Ascorbic Acid 60g SDS 1g DI Water, q.s. 1000mL final volume
In a 1L volumetric add 60g of ascorbic acid in approximately 800mL DI water. Dilute to 1000 mL with DI water and mix thoroughly. Degas for a minimum of 5 minutes. Pour into clear plastic bottle and add 1g of SDS and swirl gently. This solution is stable for 5 days. Store the solution in a clear poly container.
• 1N Hydrochloric Acid
We are currently using Fisher hydrochloric acid (catalog no.A144S-212). The HCl should be made in a large enough batches to cover the extraction and the making of the standards, blanks and QC. 2 liters is a good amount for a typical sample batch. The HCl can be made in an extra large beaker and transferred to smaller bottles.
Hydrochloric Acid 172mL DI Water 2000mL final volume
Fill ¾ with DI water and cautiously, while stirring, slowly add 172mL of hydrochloric acid. Bring to final volume of 2L. Cool to room temperature and transfer to smaller bottles.
Standard Preparation
Working standards can be made by weight or volume. Standards are made using a 1000µg/mL stock certified from AccuStandard or another source different from the QC and are made from 1N HCL. Standards are stable for one week.
Stock Standard, 10.0mg/L N
AccuStandard Stock (Phosphorous) 1mL 1N HCl 100mL final volume
In a 100mL volumetric flask containing about 80mL of 1N HCl add 1mL of stock AccuStandard phosphorus standard. Dilute to 100mL with 1N HCL and mix thoroughly. Record the information in the stock standard logbook.
Working Standard Solutions
mL(g) 10mg/L Stock mg/L P
10 1.0 5 0.5 3 0.3 1 0.1 0.5 0.05 0.25 0.025
Created By Steph Kexel SOP No: 09-033-09 Date Initiated: 12/96 Revision Date: 1/15/16 Page 70 of 97 Transfer aliquots of stock 10mg/L stock as noted above to individual 100mL volumetric flasks. Dilute to volume with 1N HCl and mix thoroughly. Record the information in working standard logbook. Prepare fresh weekly.
Sample Preparation
Sample Digestion
If not completed in the field, filter in duplicate 500mL of whole water sample through a 47mm GF/F filter (Fisher Cat # 09-874-71). Keep the filters frozen at or below -10°C until analysis.
Generally, spiked samples are spiked with 100µL of the 10ppm stock standard, yielding a spike concentration of 0.196ppm.
The quality control sample (QC) is made up in 100mL volumes per every 60 or so samples. Larger quantities are necessary if running large batches of samples. Generally the concentration of the QC is 0.3ppm and is made with 1N HCL.
Dry the filters for a minimum of one hour at 105°C, although overnight is preferable, and keep in desiccator until analysis.
Muffle the filter at 500°C for 1 hour by placing in a crucible and recording proper crucible ID numbers in the preparation logbook.
After cooling, place both filters from each site into the same 50mL digestion tube with 30mL of 1N HCl.
Filter the sample with disposable syringe and 0.45µm sterile nylon filter directly into the Lachat auto analyzer cups.
Instrumental Analysis
Analyze the sample for ortho-phosphosphorus using the Lachat ortho-phosphate method. It is assumed that the user is basically familiar with the appearance and location of the various parts of the Lachat. It is also assumed that a method for running particulate phosphorus analyses has already been created, and that the user is familiar with basic system operations. For more information on the creation of Lachat methods and on basic operations see the section entitled “The Lachat Quick Chem 8500”.
Ensure that pump tubing is pumping all reagents and proper sample loop is connected.
Ensure that the sample line from the auto-sampler is connected to port 6 of the valve.
Calculations
• Percent recovery for the spike is determined using the following formula: (A − B) %R = x100 C
Where: A = measured value in mg/L for the sample + spike B = measured value in mg/L for the original sample C = concentration of the spike in mg/
Created By Steph Kexel SOP No: 09-033-09 Date Initiated: 12/96 Revision Date: 1/15/16 Page 71 of 97 • Relative percent difference for the duplicate is calculated by the following formula: (A − B) RPD = x100 + [(A B)/ 2]
Where: A = the value in mg/L for the first run of the sample B = the value in mg/L for the second run of the sample
• Particulate Phosphorus is calculated by the following formula:
(A* B) PP(mg / L) = VolumeFiltered(L) Where: A = instrument reading (mg/L) B = volume extracted (L)
Quality Control
A certified second source quality control sample (purchased from Fisher) is analyzed for every delivery group (or every 10 samples) and the value must be within 85-115% recovery to be considered acceptable. The QC is made with 1N hydrochloric acid.
A spike is analyzed for every delivery group (or every 10 samples). The percent recovery must fall within the 85-115% recovery to be acceptable.
A duplicate is analyzed for every delivery group (or every 10 samples) and the relative percent difference must fall below 20%.
A blank is analyzed every delivery group or every 10 samples and the value must fall below the PQL to be acceptable. The blank is made with 1N hydrochloric acid.
A second quality control sample is analyzed at the end of the run and is the concentration of the PQL, or the lowest standard. Acceptable ranges for the PQL are 50-150% recovery.
Other System Notes
Chemistry Module 1-1 Sample loop: 150cm Light interference filter: 880nm Special instructions: The reaction module for phosphorus determinations comes equipped with a heating coil that heats the sample stream (after the addition of the reagents) to 39°C, which promotes better color development. This coil should be given 15 minutes to warm up before any samples are run.
Created By Steph Kexel SOP No: 09-033-09 Date Initiated: 12/96 Revision Date: 1/15/16 Page 72 of 97 Total Suspended Solids EPA 160.2
Scope and Application
The method or total suspended solids is also referred to as “Non-Filterable Residue” and is defined as those solids that are retained by a glass fiber filter and dried to constant weight at 103° to 105°C.
The Method Detection Limit (MDL) and Practical Quantitation Limit (PQL) for this analysis are determined yearly. For current MDL and PQL limits, see the chart entitled Method Detection Limit Determination.
References
Standard Method 2540D. Total Suspended Solids Dried at 103-105°C. Page 2-56—2- 58, 20th Edition, 1998, Standard Methods for the Examination of Water and Wastewater.
Method 160.2. Total Suspended Solids Dried at 103-105°C. Environmental Protection Agency.
Associated SOP’s
Refer to “SOP” titled “Hazardous Waste SOP” for proper waste disposal.
Refer to the notebook titled “SOP’s” located in the nutrients laboratory.
Safety and Waste Disposal
Refer to the University of Connecticut’s Environmental Health and Safety Chemical Health and Safety web page at:
http://www.ehs.uconn.edu/ppp/index.php
A hard copy of the Chemical Hygiene Plan can be found on the notebook rack located on the lab bench. Also refer to the Hazardous Waste SOP.
Interferences
Exclude large particles or submerged agglomerates of non-homogeneous materials from the sample if it is determined that their inclusion is not desired in the final result.
For samples high in dissolved solids, thoroughly wash the filter to ensure removal of the dissolved material. Prolonged filtering times resulting from filter clogging may produce higher results owing to increased colloidal materials captured on the clogged filter.
Too much residue on the filter may cause a water-entrapping crust; limit the sample size to that yielding no more than 200mg residue.
Created By Steph Kexel SOP No: 09-033-09 Date Initiated: 12/96 Revision Date: 1/15/16 Page 73 of 97 Materials
Whatman ProWeigh GF/F glass fiber filters (Fisher Cat # 09-735-56) Mettler Analytical Balance Drying Oven Desiccator
Sample Handling
Analysis of whole water samples should begin as soon as possible not to exceed 7 days. Refrigeration or icing to 4°C is recommended for unfiltered samples.
Filters for LISS are delivered and stored in the freezer at or below -10°C until time of analysis.
Procedure
Samples are immediately prepped for TSS analysis. Refrigerate sample at 4°C up to the time of analysis to minimize microbiological decomposition of solids. In no case hold sample for more than 7 days before filtering.
The filtering apparatus is rinsed with 1N hydrochloric acid and then rinsed three times with DI Water using a beaker to catch filtered water for wastes. Place a TSS pre- weighed filter on filtering platform, and rinse with DI Water. Record initial filter weight and tin ID in the logbook. Write the sample ID on the tin with a sharpie.
Shake sample bottle well.
Pour 500mL of sample into a clean, acid washed graduated cylinder and pour into the filtering apparatus.
Limit the sample size to that yielding no more than 200mg of residue because excessive residue on the filter may form a water-entrapping crust.
Pour sample into the filtering apparatus and rinse graduated cylinder 3 times with at least 50mL of DI water and pour into the filtering cup. Then, rinse the sides of the filtering cup with DI Water to ensure all particulate matter is captured on the TSS filter. Leave the filter on the filtering apparatus until dry before taking it off.
Fold the filter in half so as not to lose any of the particulates. Place filter in tin and cook in oven at 103°-105°C overnight (approximately 16 hours), and then place in desiccator until cool before weighing. Record date, analyst, tin ID, initial weight, and volume filtered in the logbook.
Calibrate balance by pressing and holding the zero button until the display flashes “100g”. Move the sliding knob on the right side of the balance all of the way to the back. Wait until the balance flashes “0”, then slide the knob forward and wait. When finished, the balance should read 0.0000g. Use calibrated weights to verify the calibration of the balance and to check for accuracy. Record the values in the balance verification logbook. Weigh filters and record final weights in logbook.
Ensure that a constant weight has been reached by putting the filters back in the oven for 1 hour and then into the desiccator. After the 2 hour cool down period, record the second weight. When new projects or unknown samples are analyzed, they must be baked,
Created By Steph Kexel SOP No: 09-033-09 Date Initiated: 12/96 Revision Date: 1/15/16 Page 74 of 97 weighed, and then re-baked and re-weighed until a constant weight is achieved, change being either less that 4% of previous weight, or 0.5mg, whichever is less.
For LISS and CT DEEP river samples, a comparative study has been performed in which no significant difference in weights was observed between initial sample weights and either wt. #1 (samples baked overnight) or wt. #2 (samples re-baked for 1 hour after overnight bake). Therefore, after an overnight baking, samples for these projects do not need to be re-baked and re-weighed. This data is available upon request.
Calculations
• To calculate TSS: (A − B)x1000000 mg TSS/L = sample volume in mL
Where: A = weight of filter and residue in grams B = weight of original filter in grams
• Relative percent difference for the duplicate is calculated by the following formula: (A − B) RPD = x100 + [(A B)/ 2]
Where: A = value in mg/L for the first run of the sample B = value in mg/L for the second run of the sample
Quality Control
A certified quality control sample is purchased from ERA (CAT# 510 Small Lab Minerals) and is filtered along with samples. It is run every delivery group or every 20 samples and the value must be within 85-115% recovery to be considered acceptable.
A duplicate is filtered per delivery group or every 20 samples and must have an RPD below 20% to be considered acceptable.
A blank is filtered per delivery group or every 20 samples and the value must fall below the PQL to be considered acceptable.
Created By Steph Kexel SOP No: 09-033-09 Date Initiated: 12/96 Revision Date: 1/15/16 Page 75 of 97 Chlorophyll EPA 445.0
Scope and Application
EPA Method 445.0 is the reference method for measuring chlorophyll-a in seawater by flourometric analysis. This section provides a stepwise procedure for bench use by laboratory personnel.
This method for determining chlorophyll-a is more sensitive than the spectrophotometric method.
The fluorometer is calibrated with purchased chlorophyll-a standards of known value from Turner Designs (Cat. # 10-850).
The Method Detection Limit (MDL) and Practical Quantitation Limit (PQL) for this analysis are determined yearly. For current MDL and PQL limits, see the chart entitled Method Detection Limit Determination.
A Chla-NA module is used in the instrument which eliminates the need for the acidification step in the EPA method.
Summary of Method
A known volume of water is filtered through a 25mm, 0.7µm GF/F filter and the resulting pigments are extracted with a 90% acetone solution. The fluorescence of the extract is determined with a fluorometer and the chlorophyll-a concentration is calculated.
Fluorescence is temperature dependent with higher sensitivity occurring at lower temperatures. Samples, standards, blanks and spikes must all be at the same temperature.
Interferences
Any substance extracted for the filter or acquired from laboratory contamination that fluoresces in the red region of the spectrum may interfere in the accurate measurement of chlorophyll-a.
References
EPA Method 445.0. In Vitro Determination of Chlorophyll a and Pheophytin a in Marine and Freshwater Algae by Fluorescence. Revision 1.2, September, 1997. National Exposure Research Laboratory, Office of R &D, U.S.E.P.A., Cincinnati, OH 45268
Associated SOP’s
Refer to “SOP” titled “Hazardous Waste SOP” for proper waste disposal.
Refer to the notebook titled “SOP’s” located in the nutrients laboratory.
Created By Steph Kexel SOP No: 09-033-09 Date Initiated: 12/96 Revision Date: 1/15/16 Page 76 of 97 Safety
Acetone is extremely flammable and is an eye, mucous and skin irritant. Wear appropriate safety glasses and gloves and use in the hood.
Refer to the University of Connecticut’s Environmental Health and Safety Chemical Health and Safety web page at:
http://www.ehs.uconn.edu/ppp/index.php
A hard copy of the Chemical Hygiene Plan can be found on the notebook rack located on the lab bench. Also refer to the Hazardous Waste SOP.
Materials
Turner Trilogy Fluorometer
Procedure
Reagent Preparation
Unless otherwise specified, all chemicals should be ACS grade or equivalent. Deionized water refers to high quality reagent water, Type I or Type II as defined in ASTM Standards, Part 31, and section D1193-75.
• Aqueous Acetone
Acetone 90mL Deionized Water 10mL
Combine 90mL of acetone with 10mL of deionized water and mix thoroughly. We are currently using Fisher acetone (catalog no. A949-4). Solution is stable for 3 months.
Standard Preparation
We are currently using primary chlorophyll-a standards purchased from Turner Designs (Cat. # 10-850). The two concentrations come in a high and low concentration, and the analyst must dilute the high standard to create a mid-range calibration point.
It is important to pay close attention to pouring chlorophyll standards, to be careful not to lose sample volume. Acetone rapidly evaporates. Be sure to keep all vials capped tightly at all times.
Sample Preparation
A known volume of water is passed through a 25mm, 0.7µm GF/F filter pad in the field. The pad is then folded in half and stored in aluminum foil, labeled, and frozen at or below -10°C until time of analysis. Filters can be stored frozen for 28 days without sample degradation.
Samples may also be filtered in the laboratory and appropriate volumes of sample filtered are recorded and apparatus is rinsed with copious amounts of deionized water before each sample is filtered. Unfiltered water samples are stored in brown bottles in the dark at 4ºC., and should be filtered within 24 hours.
Created By Steph Kexel SOP No: 09-033-09 Date Initiated: 12/96 Revision Date: 1/15/16 Page 77 of 97 Filter Extraction
Before analysis, the filter pad is thawed and then placed in a 30mL glass screw top test tube.
Next, add 10mL of 90% aqueous acetone and allow sample to steep.
The tube is then gently shaken and allowed to steep for 1 hour before gently shaken again. The samples are allowed to extract for not more than 24 hours in the dark, in the freezer.
Avoid any direct light throughout this analysis as it can increase the chlorophyll concentration!!!
Instrumental Analysis
It is assumed that the user is basically familiar with the appearance and location of the various parts of the Turner 450 fluorometer.
The tubes are removed from the freezer with the standards and spiking solution and are allowed to warm to room temperature under dark conditions (typically in the cabinet under the hood) until warm so no condensation appears on the outside of the glass test tube.
Calibration of the Fluorometer
Primary chlorophyll standards are purchased from Turner Designs, 845 W. Maude Avenue, Sunnyvale, CA 94085, and are supplied in 20mL vials (Cat # 10-850).
Prepare dilutions of the extracts using 90% acetone to provide concentrations in the appropriate range of µg/L of chlorophyll-a.
It is important not to leave test tube caps open for any length of time as acetone evaporates quickly and this will alter the chlorophyll-a reading.
• On the Trilogy fluorometer select Calibrate → New → ug/L
• Use a test tube with 90% acetone for the blank, make sure to wipe down the test tube with a Kimwipe before placing it to be read.
• Next pour the standards, lowest to highest in three separate test tubes and read. o Enter standard concentration → OK → Enter more Stds o Continue with calibration? → yes, save calibration as date (mmddyy)
Sample Analysis
The adjustable solid secondary standard provides a very stable fluorescent signal. It has an adjustment screw so that it can be tuned to match sample concentrations. It is used to check the stability of the instrument as a second source quality control sample. Control charts are kept to verify a valid acceptance range over time. A chart in the beginning of the CHLa logbook is updated periodically with new acceptance criterion.
Then a low standard (CCV) and blank are used every 20 samples as a continuing calibration verification.
• Press sample ID, the first sample is the QC, the second is the Blank, then the actual samples. Type QC2NDSOURC for the sample name. The 2nd source QC is
Created By Steph Kexel SOP No: 09-033-09 Date Initiated: 12/96 Revision Date: 1/15/16 Page 78 of 97 located in the small black box next to the machine. The text tube holder in the machine needs to be removed before putting the QC in.
• Press “Measure fluorescence”. For the QC and Blank the volume filtered = 1mL, the solvent added = 1mL. For all other samples the volume filtered = check the PREP LOG book and the solvent added = 10mL.
• After you have finished reading all the samples (including a duplicate per 20 samples, one LCS, and one SPK per every 40 samples) save the Excel worksheet on a removable flash drive as Chla+date (mmddyy).
• For the LCS and SPK only use LISS samples: o LCS = 500µL of spike solution in 5mL of 90% acetone o SPK = 500µL of spike solution in 5mL of sample (record sample number) o When measuring the LCS and SPK the volume filtered (for both) is the same as the volume filtered for the sample that is being used for the SPK. o The volume of the solvent is 10mL
• For LISS Samples:
o Filtered sample volume = 400mL o Solvent volume = 10mL o This is because there are two filters that each have 200mL filter volume.
Calculations
• Percent recovery for the spike is determined using the following formula: (A − B) %R = x100 C
Where: A = measured value in µg/L for the sample + spike B = measured value in µg/L for the original sample C = concentration of the spike in µg/L
• Relative percent difference for the duplicate is calculated by the following formula: (A − B) RPD = x100 + [(A B)/ 2]
Where: A = value in µg/L for the first run of the sample B = value in µg/L for the second run of the sample
Created By Steph Kexel SOP No: 09-033-09 Date Initiated: 12/96 Revision Date: 1/15/16 Page 79 of 97 Quality Control
A laboratory control sample (LCS) is run for every batch of samples. The spiking solution is made by combining a few high concentration samples and mixing thoroughly. This is then spiked to deionized water as the LCS to verify the concentration of the spike. Typically, 500µL of the spiking solution is added to 5mL of either the 90% acetone for the LCS sample or 5mL of sample for the spiked sample.
One of the standards is run throughout the sample analysis as a quality control sample and is analyzed for every delivery group (or every 20 samples) and the value must be within 85-115% recovery to be considered acceptable.
A duplicate is analyzed for every delivery group (or every 40 samples). The duplicate relative percent difference (RPD) must be below 20%.
A blank is analyzed every delivery group or every 20 samples and the value must fall below the PQL to be considered acceptable.
A solid secondary standard cell is run with every batch. Control charts are updated periodically and acceptable ranges are found in the front of the CHLa logbook.
Created By Steph Kexel SOP No: 09-033-09 Date Initiated: 12/96 Revision Date: 1/15/16 Page 80 of 97 Dissolved Organic Carbon EPA 415.1
Scope and Application
The organic carbon in water is composed of a variety of organic compounds in various oxidation states. To determine the quantity of organically bound carbon the organic molecules must be broken down to a single carbon unit and converted to a single molecular form that can be measured quantitatively.
In this method, total carbon (TC) and total inorganic carbon (TIC) are converted to carbon dioxide (CO2) at 680°C using a platinum catalyst bed in the reaction chamber. Detection is by non-dispersive infrared (NDIR). The holding time is 28 days.
Summary of Method
Non-Purgeable Organic Carbon (NPOC) values are obtained by acidifying the sample with 1 mol/L hydrochloric acid to a pH of 2 to 3. Sparge gas (Ultra Zero Compressed Air) is bubbled through the sample to eliminate the IC component and the remaining TC is measured in the method described above. This analysis value is referred to NPOC to distinguish it from the TOC value obtained by calculating the difference between TC and IC. It is the non-purgeable organic carbon that is present in a sample in non-volatile form. In the Nutrients Laboratory, NPOC is referred to as TOC as reporting calculated TOC values have not been requested by clients.
Dissolved organic carbon (DOC) is measured by filtering the sample with a 47mm GF/F filter and purging off TIC. LISS samples are run in this manner.
The Method Detection Limit (MDL) and Practical Quantitation Limit (PQL) for this analysis are determined yearly. For current MDL and PQL limits, see the chart entitled Method Detection Limit Determination.
Definitions
NDIR (Non-Dispersive Infrared) - A polyatomic molecule such as CO2 absorbs infrared radiation of different wavelengths depending upon the bonding condition or kind of atoms comprising the molecule. The amount of rays absorbed is directly proportional to the density of the gas according to Lambert-Beer’s Law. The density of the gas can be obtained by measuring the amount of rays absorbed by using a dual beam photometer that employs the principle of pressure difference between two detector chambers resulting in an analog signal.
Purge - Acidification of a water sample, which converts inorganic carbon to carbon dioxide gas.
References
TOC-L Total Organic Carbon Analyzer Manual. Shimadzu 2010.
Method 415.1. Organic Carbon, Total (Combustion or Oxidation). Editorial Revision 1974. Environmental Protection Agency.
Created By Steph Kexel SOP No: 09-033-09 Date Initiated: 12/96 Revision Date: 1/15/16 Page 81 of 97 Standard Method 5310 A & B. Total Organic Carbon by High-Temperature Combustion. Page 5-18—5-22, 20th Edition, 1998, Standard Methods for the Examination of Water and Wastewater.
Associated SOP’s
Refer to “SOP” titled “Hazardous Waste SOP” for proper waste disposal.
Refer to the notebook titled “SOP’s” located in the nutrients laboratory.
Safety
Refer to the University of Connecticut’s Environmental Health and Safety Chemical Health and Safety web page at:
http://www.ehs.uconn.edu/ppp/index.php
A hard copy of the Chemical Hygiene Plan can be found on the notebook rack located on the lab bench. Also refer to the Hazardous Waste SOP.
When packing tubes, use proper protective gear and work in hood as reagents are hazardous.
The waste of the instrument is captured in a hazardous waste bin and labeled “pH < 1”.
Materials
Shimadzu Total Organic Carbon Analyzer - Model TOC-L ASI-L Shimadzu Autosampler
Procedure
Standard Preparation
Deionized water (DI) refers to high quality reagent water, TYPE I or TYPE II as defined in ASTM Standards. Use DI water to prepare all standards. They are made fresh daily.
Dissolved Organic Carbon Standards
Transfer aliquots of AccuStandard 1000µg/mL stock as noted below to individual 100mL volumetric flasks. This standard is certified and from AccuStandard and is kept in the standards drawer. Dilute to final volume of 100mL with DI water and mix thoroughly. Record in standard logbooks. Prepare fresh daily.
Final Standard Conc. (ppm) Volume of Stock (mg/L) 1.0 0.1 5.0 0.5 10.0 1.0
Created By Steph Kexel SOP No: 09-033-09 Date Initiated: 12/96 Revision Date: 1/15/16 Page 82 of 97 Reagents and gas
• Hydrochloric Acid—Used for pre-acidification (1mol/L)
Fill 250mL volumetric flask roughly half-way with DI water. Add 20.5mL of concentrated HCl and dilute to final volume.
• 2M Hydrochloric Acid—used to recondition the catalyst
Add 168mL of HCl to a 1 Liter bottle filled ½ way with deionized water. Mix and dilute to a final volume with deionized water.
• Compressed Air - Recommended Ultra Zero grade
Sample Preparation
Samples may be stored frozen for 28 days in a freezer at or below -10°C. No preparation is needed.
Instrument Analysis
Instrument Start-Up
Turn on the gas, power switch on the back panel of the instrument, and left side of auto sampler. After instrument is on for a few minutes, start computer and open software by clicking
Open the front panel of the instrument and make sure the humidifier is filled with DI water between the two marks on the cup.
Check the acid volume and the DI water bottle on the left side of the instrument.
Dump and rinse the 1 gallon amber glass jug to the left of the auto sampler and replace with new DI water.
Click
In the upper right hand corner of the window, press
In the sample table highlight
A window will pop up. Under the method section, click on <…> and click
A new window pops up. For number of samples enter <5> and start vial enter <1>. Change the sample name from “cal” to
Created By Steph Kexel SOP No: 09-033-09 Date Initiated: 12/96 Revision Date: 1/15/16 Page 83 of 97 The vial settings screen pops up and the vial numbers are auto generated. Press
Save the file by clicking on the top left of the window
The window pops up asking to save the file. Ensure the date is correctly entered and press
Another window will pop up asking if, after analysis is complete, the instrument should keep running, shut down or go into sleep mode. If beginning a new run, select
The instrument holds its calibration for many months before the catalyst must be re- conditioned. If blanks are not stabilizing and the second source quality control sample (QC) doesn’t pass within limits, then a new calibration must be performed and/or a new combustion tube must be inserted into the instrument.
Instrument calibration
Create a new schedule as above. Right click on
Use the 1000uL Acculon stock standard to make the 1.0 and 5.0 and 10.0 ppm working standards and record in the standards log book.
Click on the top right corner
Once the calibration is finished, it will automatically save the file with a new name that is date/time driven. For example, 2-6-11.2014_03_12_16_06_37.cal> was run on 3/12/2014 at 04:06:37pm.
To review a calibration and print the data, click on the tab at the bottom of the sub window in the top left hand corner of the page that looks like a graph. Pick the correct calibration and review the R^2 value and graphs. The R^2 must be at least 0.995.
Running the First Quality Control
After calibrating the instrument, a second source QC from ERA (cat number 516) is made and run to verify the calibration. It must be within 85-115% recovery to continue with running samples. Follow instructions from ERA on making the QC.
In the same sample table below the calibration line, insert two more samples and add an Initial Calibration Verification (ICV) and an Initial Calibration Blank (ICB) as explained above changing the sample name to ICV and ICB. Click
Load the auto sampler with the correct samples. Click on
Created By Steph Kexel SOP No: 09-033-09 Date Initiated: 12/96 Revision Date: 1/15/16 Page 84 of 97 Creating a Sample Sequence
The same ERA Initial Calibration Verification is used as a Continuing Calibration Verification (QC) every 10 samples or at the start of every new day. It must be made up fresh every day. Begin a new day by running the QC. Insert new samples into the sample table as mentioned above.
When running a large group of samples, insert or copy lines from above, deleting the sample ID. Once the samples have been inserted, type the new
The software is similar to excel in that lines can be copied or deleted by right clicking on the line. In this screen it is possible to enter sample ID directly in the column.
Pour of the samples and enter their location in the auto sampler tray correctly on the
To start the run, press
Aborting a Sequence
In the top right hand corner of the main window, select
When re-starting after aborting a sample, ensure that a few rinse vials are run to purge any residual sample.
Shutting down the TOC
In the main page, select
Cleaning the Combustion Tube and Reconditioning the Catalyst
Refer to the manual for cleaning and packing the column.
When a new tube is inserted into the instrument, blank DI water samples should be run until the baseline stabilizes.
Calculations
• Percent recovery for the spike is determined using the following formula: (A − B) %R = x100 C
Where: A = measured value in mg/L for the sample + spike B = measured value in mg/L for the original sample C = concentration of the spike in mg/L
Created By Steph Kexel SOP No: 09-033-09 Date Initiated: 12/96 Revision Date: 1/15/16 Page 85 of 97 • Relative percent difference for the duplicate is calculated by the following formula: (A − B) RPD = x100 + [(A B)/ 2]
Where: A = the value in mg/L for the first run of the sample B = the value in mg/L for the second run of the sample
Quality Control
• A certified second source quality control sample (purchased from Fisher) is analyzed for every delivery group (or every 10 samples) and the value must be within 85-115% recovery to be considered acceptable.
• A spike is analyzed for every delivery group (or every 10 samples). The percent recovery must fall within the 85-115% recovery to be considered acceptable.
• A duplicate is analyzed for every delivery group (or every 10 samples). The duplicate relative percent difference (RPD) must be below 20%.
• A blank is analyzed every delivery group or every 10 samples and the value must fall below the PQL to be considered acceptable.
Created By Steph Kexel SOP No: 09-033-09 Date Initiated: 12/96 Revision Date: 1/15/16 Page 86 of 97 Biochemical Oxygen Demand 405.1 Modified
Scope and Application
EPA Method 405.1 is used in this method. In this method, dissolved oxygen in sea water is measured at 5 day intervals for 30 days. The effect of salinity and temperature on the solubility of oxygen in water is corrected for in this procedure.
Summary of Method
The BOD test is essentially a bioassay procedure involving the measurement of oxygen consumed by living organisms while utilizing the organic matter present in the sample under conditions as similar as possible to those that occur in nature. The sample is placed in an air-tight container and incubated at constant temperature for a pre-selected period of time. In the standard test, a 300mL BOD bottle is used and the sample is incubated at 20°C. for 30 days. Light must be excluded to prevent algae growth, which would produce oxygen in the bottle. Dissolved oxygen is measured initially and every 5 days after incubation. Because of the limited solubility of oxygen in water (about 9 mg/L at 20°C.), the sample is adjusted to approximately 20°C. and aerated with diffused air to increase the dissolved gas content to near saturation at the beginning of the test.
A thin permeable membrane stretched over the sensor of the BOD meter, isolates the sensor elements from the environment, but allows oxygen to enter. When a polarizing voltage is applied across the sensor, oxygen that has passed through the membrane reacts at the cathode, causing a current to flow. If the oxygen pressure increases, more oxygen diffuses through the membrane and more current flows through the sensor. A lower pressure results in loss of current.
Definitions
BOD (Biochemical Oxygen Demand) -- The amount of oxygen required by bacteria while stabilizing decomposable organic matter under aerobic conditions.
Salinity - The electrical conductivity of water relative to a specified solution of KCl and water.
Chlorinity - Salinity * 1000 / 1.8
Nitrifying bacteria - Certain autotrophic bacteria which oxidize, for energy, non- carbonaceous matter such as ammonia which is converted to nitrous and nitric acid. They are usually present in relatively small numbers in untreated domestic waste water, and their reproductive rate at 20°C is such that their populations do not become sufficiently large to exert an appreciable demand for oxygen.
Inhibiting - the process of adding a chemical such as 2-chloro-6-tri-chloromethyl pyridine to the BOD bottle to eliminate the interference caused by nitrifying bacteria.
Created By Steph Kexel SOP No: 09-033-09 Date Initiated: 12/96 Revision Date: 1/15/16 Page 87 of 97 Interferences
If large amounts of nitrifying bacteria are present in the sample, errors may be introduced to the BOD results, particularly in the 30 day BOD. Inhibition of nitrification is recommended in these instances. (Not done for LISS seawater samples)
Samples containing residual chlorine may inhibit the reaction. To remove chlorine, aerate for two hours or treat the sample with sodium sulfite. (Not done for LISS seawater samples)
Samples supersaturated with dissolved oxygen (more than 9mg/L) may be encountered in cold water or in water where photosynthesis occurs. To prevent loss of oxygen during incubation of such samples, bring sample to near 20°C and aerate for 15 minutes with compressed air.
Safety
Refer to the University of Connecticut’s Environmental Health and Safety Chemical Health and Safety web page at:
http://www.ehs.uconn.edu/ppp/index.php
A hard copy of the Chemical Hygiene Plan can be found on the notebook rack located on the lab bench. Also refer to the Hazardous Waste SOP.
Materials
Dissolved Oxygen Meter—Fisher Accumet XL 40 BOD Bottles - 300mL capacity with ground glass stoppers and plastic caps. Incubator - Thermostatically controlled at 20°C (+ or - 1°C). All light must be excluded.
Sample Preparation
Samples should be analyzed within 6 hours of collection since samples may degrade significantly during storage between collection and analysis, resulting in low BOD values. If analysis cannot proceed immediately, cool to 4°C in the dark for 48 hours, but no more than 72 hours.
Prior to analysis, samples should be warmed to at least 15°C and aerated with compressed air for a minimum of 15 minutes.
Procedure
Since solubility of oxygen decreases with salinity, this factor must be accounted for by setting the O2 saturation level to the average LISS salinity of 19ppt.
Label two BOD bottles with sample number and A and C. Bottle C will be used to refill A during the reading intervals. Take readings at 5, 10, 15, 20, 25 and 30 days. If the reading falls below 3.0mg/L at any interval, the sample must be re-aerated. Pour the samples from both bottles into a bottle and aerate with compressed air for a minimum of
Created By Steph Kexel SOP No: 09-033-09 Date Initiated: 12/96 Revision Date: 1/15/16 Page 88 of 97 15 minutes. Refill the bottles and reread bottle A. Put the initial reading before aeration and the second reading after aeration on the worksheet.
Press and hold the button on the right side of the XL40 meter to turn it on and login with initials and password and press “LOGIN”. Make sure the meter is in DO mode and the correct salinity is in the bottom right box (19ppt for LISS). To change the salinity, press “SETUP” then “CHANGE PPT VALUE” and press “OK”. Press “standardize” on the top right and press “clear” to clear the standardization. Ensure that reading is stable by looking at the graph and press “confirm”. To show the graph press the “graph” button or “hide” to minimize.
Insert probe in sample and turn the red switch on to allow for mixing, and read the BOD. The initial readings should be about 8.0 and should decrease with each progressive reading. Do not leave meter mixing (red switch on) while out of sample!!
Pour off sample on D0, D20 and D30 on designated day in 40mL scintillation vial and add 1 drop of concentrated sulfuric acid. Keep in walk-in cooler.
Cap BOD bottles and keep in BOD incubator in order of LIMS number. Read BOD values every 5 days up until day 30.
To shutdown, press the bottom left corner of the screen and the “start” menu will pop up. Press “shutdown” then it will prompt if you are sure and press “yes”
Calculation:
Day 0 reading minus Day 30 reading = BOD mg/L.
If sample is aerated, this must be accounted for.
Example:
(Day 0 = 8.0 mg/L) (Day 5 = 3.0 mg/L) aerated to 8.0 mg/L (Day 10 = 6.0 mg/L) (Day 15 = 5.0 mg/L) (Day 20 = 4.5 mg/L) (Day 25 = 4.0 mg/L) (Day 30 = 3.8 mg/L)
Calculation: Day 0 - Day 5 (8.0 - 3.0 = 5.0) Day 5 aerated - Day 10 (8.0 - 6.0 = 2.0) Day 10 - Day 15 (6.0 - 5.0 = 1.0) Day 15 - Day 20 (5.0 - 4.5 = 0.5) Day 20 - Day 25 (4.5 - 4.0 = 0.5) Day 25 - Day 30 (4.0 - 3.8 = 0.2) Total = 9.2 mg/L
Created By Steph Kexel SOP No: 09-033-09 Date Initiated: 12/96 Revision Date: 1/15/16 Page 89 of 97 Data Review
This document is designed to offer guidance in laboratory data evaluation and validation. In some aspects, it is equivalent to a standard operating procedure (SOP) in other, more subjective areas, only general guidance is offered due to the complexities and uniqueness of data relative to specific samples.
Those areas where specific SOP’s are possible are primarily areas in which definitive performance requirements are established. These requirements are concerned with specifications that are not sample dependent; they specify performance requirements on matters that should be fully under laboratory control. These specific areas include laboratory preparation and verification blanks, calibration standards, and calibration verifications. The exception to this is the area of individual sample analysis; if the nature of the sample itself limits the attainment of specification, appropriate allowances must be made.
With these concepts in mind, this guideline is designed to permit structured data review. Objective, unambiguous requirements are easily and efficiently delegated to personnel other than experienced professionals. To this end, the guideline is arranged in order, with the most objective, straightforward validation elements given first.
In order to use this document effectively, the reviewer should have a general overview of the survey at hand. The exact number of samples, their assigned field sheets and laboratory numbers, their matrix, the identity of any field quality control (QC) samples (blanks, duplicates, spikes, splits, performance audit samples), sampling dates and the number of labs involved for their analysis are essential information. Background information and historical data are extremely helpful.
The chain of custody record provides sample descriptions, field stations and corresponding laboratory numbers, and the date of sampling. Although the sampling date is not addressed by contract requirements, the reviewer should be aware of any lag time between sampling and shipping. The case narrative is another source of general information. Notable problems with matrices, insufficient sample for analysis or reanalysis, and unusual events should be found here. The requirements to be checked in validation, in order, are as follows:
I. Sample Holding Times II. Calibration a. Initial Calibration and Calibration Verification b. Continuing Calibration Verification c. Calibration Blank III. Blanks a. Laboratory Preparation Blank b. Field Blank IV. Specific Sample Results a. Duplicate Sample Analysis (Laboratory and Field) b. Spike Sample Analysis
Data are reviewed by the analyst and the data report is generated via spreadsheet. The report undergoes a 100% peer review to ensure that the raw data is in agreement with the reported data. Finally, the report is reviewed by the Senior Analyst or other appropriate personnel for a 30% data review, including checking the agreement of the raw data versus reported results as well as a verification of any calculations. The report then undergoes at 10% review by the QA officer. A project narrative is developed for each report and the hard copy as well as the digital copy are delivered to the client.
Created By Steph Kexel SOP No: 09-033-09 Date Initiated: 12/96 Revision Date: 1/15/16 Page 90 of 97 Sample Holding Times
Objective
The objective is to determine the validity of results based on the holding time of the sample from the time of collection to time of analysis or sample preparation, as appropriate. From the standpoint of the laboratory performance, the time of laboratory receipt until analysis or sample preparation is needed to determine compliance with sample holding time requirements.
Requirements
The following holding time requirements were established in the Quality Assurance Project Plan for the Long Island Sound Study.
Contract Required Holding Times:
NAME HOLDING TIME
Ammonia 14 days
Nitrate + Nitrite 28 days
Organic Carbon, Dissolved 28 days
Carbon, Particulate 28 days
Total Dissolved Nitrogen 28 days
Particulate Nitrogen 28 days
Ortho-phosphate 28 days
Total Dissolved Phosphorus 28 days
Particulate Phosphorus 28 days
Dissolved Silica 28 days
Biogenic Silica 28 days
Chlorophyll-a 28 days
Total Suspended Solids 7 days
Biochemical Oxygen Demand 48 hours
Created By Steph Kexel SOP No: 09-033-09 Date Initiated: 12/96 Revision Date: 1/15/16 Page 91 of 97 Evaluation Procedure
Actual holding times are established by comparing the sample date on the chain of custody record with the date of analysis found in the laboratory data. Contractual holding times are established by comparing the time of sample receipt with the dates of analysis. Exceeding the holding time for a sample generally affects a loss of the analyte(s). This occurs through any number of mechanisms, such as, depositions on the sample container walls or precipitation. Therefore, when holding time violations occur, the results which are most severely called into question are those which fall close to or below the detection limit. Determination of the effect of holding time violations on the usability of analytical results is extremely subjective. The degree and nature of the effect is dependent on multiple factors, such as the nature of the analyte and matrix, the degree of the violation (days), and the concentration of the analyte in the sample. Ultimately, the decision whether to accept the data is best left to the data reviewer or users professional judgment.
Created By Steph Kexel SOP No: 09-033-09 Date Initiated: 12/96 Revision Date: 1/15/16 Page 92 of 97 Calibration and QA Acceptance Policy
Initial Calibration and Calibration Verification
Objective
The objective in establishing compliance requirements for satisfactory instrument calibration is to ensure that the instrument is capable of producing acceptable quantitative data. Initial calibration demonstrates that the instrument is capable of acceptable performance at the beginning of the sample analysis runs.
Requirements
For each of the categories listed below the following criteria apply:
• Instruments must be calibrated daily and each time the instrument is setup or as per SOP requirements.
• Calibration verification shall be made by the analysis of EPA quality control solutions.
• Where an EPA QC sample is not available the accuracy of the calibration shall be conducted on an independent standard at a concentration other than that used for calibration, but within calibration range.
Lachat Auto Analyzer Analysis
• Calibration blank and five standards must be used in establishing the analytical curve.
• Calibration verification must fall within the control limits of 85 to 115% of the true value.
Total Organic Carbon Analysis
• Calibration blank and at least one standard must be used in establishing the analytical curve.
• Calibration verification must fall within the control limits of 85 to 115% of the true value.
Evaluation Procedure
• Verify that the instrument was calibrated at the proper frequency using the correct number of standards and calibration blank.
• Verify that calibration verification source used met contract requirements.
• Review data package for acceptance criteria. Spot check calibration verification for each sample delivery group by recalculation of the percent recovery from the raw data; verify that the recalculation value agrees with the laboratory reported value.
Created By Steph Kexel SOP No: 09-033-09 Date Initiated: 12/96 Revision Date: 1/15/16 Page 93 of 97 Continuing Calibration Verification (CCV)
Objective
CCV demonstrates that the instrument is capable of acceptable instrument performance (calibration accuracy) over a specific time period.
Requirements
For each of the categories listed below the following criteria apply:
• CCV and continuing calibration blank (CCB) are performed every 10 samples.
• CCV is made by the analysis of EPA quality control solutions. Where an EPA QC sample is not available the accuracy of the calibration is conducted on an independent standard at a concentration other than that used for calibration, but within calibration range.
• The calibration blank must be less than the contract required detection limit.
Auto Analyzer Analysis
Continuing calibration verification must fall within the control limits of 85 to 115% of the true value.
Total Organic Carbon Analysis
Continuing calibration verification must fall within the control limits of 85 to 115% of the true value.
Evaluation Procedure
Review the supporting raw data to verify that continuing calibration verification and continuing calibration blank analysis were preformed at the proper frequency.
• Verify that calibration verification source used met contract requirements.
• Review data package for acceptance criteria. Spot check calibration verification for each sample delivery group by recalculation of the percent recovery from the raw data; verify that the recalculation value agrees with the laboratory reported value.
Blanks
Objective
The assessment of results on blank analysis is for the purpose of determining the existence and magnitude of contamination problems. The criterion for evaluation of blanks applies to all blanks (reagent, method, and field). The responsibility for action in the case of unsuitable blank results depends on the circumstances and the origin of the blank. If problems with any blank exist, all data associated with the survey and/or sample delivery group must be carefully evaluated.
Created By Steph Kexel SOP No: 09-033-09 Date Initiated: 12/96 Revision Date: 1/15/16 Page 94 of 97 Requirements
The laboratory preparation blank (reagent blank) is the only in-house blank the laboratory is responsible for reporting and:
• At least one preparation blank must be prepared and analyzed for every sample delivery group (10 samples) received or for each batch of samples digested.
• If the concentration of the blank is less than the contract requirement detection limit (CRDL), no corrective action is required. If the concentration of the blank is above the CRDL for any group of samples associated with a particular blank, the concentration of the sample with least concentrated analyte must be 10X the blank concentration. The sample value is not to be corrected for the blank value.
• Results must be reported to the instrument detection limit.
• No contractual criteria apply to the levels of contaminant in field blanks.
Evaluation Procedures
Review the results to determine if any blank contamination is identified at levels greater than the CRDL, and then compare blank levels to that of the sample to determine compliance.
Duplicate Sample Analysis
Objective
The relative percent difference (RPD) data is used to evaluate the long term precision of the method for each parameter. The data reviewer can use the results of the duplicate analysis as an indicator of the precision of the sample results.
Requirements
• At least one duplicate sample must be analyzed from each group of samples of a similar matrix or 10 samples, which ever is more frequent.
• Samples identified as field blanks cannot be used for duplicate analysis.
• A control limit of + 20% RPD shall be used on sample > 5 times the MDL.
• For samples less than the MDL the RPD is not calculated.
• No contractual criteria apply to the results of field duplicates.
Evaluation Procedure
Review data and determine the raw data for the field and laboratory duplicates. Verify the calculation of the RPD and verify results have been correctly reported.
Created By Steph Kexel SOP No: 09-033-09 Date Initiated: 12/96 Revision Date: 1/15/16 Page 95 of 97 Discussion
Action taken as a result of duplicate sample analysis must be weighed carefully since it may be difficult to determine if poor precision is a result of sample non-homogeneity, method defects or laboratory technique. In general the results of duplicate sample analysis should be used to support conclusions drawn about the quality of the data rather than a basis of these conclusions.
Spiked Sample Analysis
Objective
The spiked sample analysis is designed to provide information about the effect of the sample matrix on the digestion and measurement methodology. A known quantity of the method analyte is added to an aliquot of sample and analyzed exactly like a sample.
Requirements
• At least one spike sample analysis must be analyzed from each group of samples of a similar matrix or 10 samples, which ever is more frequent.
• Samples identified as field blanks cannot be used for spike sample analysis.
• If the spike recovery is not within the limits of 85 to 115%, the data of all the samples associated with the spiked sample must be flagged to indicate recovery problems. An exception is granted when sample concentration exceeds the spike concentration by a factor of 4 or more.
• When sample concentration is less than MDL, sample recovery (SR) = 0 may be used for the purpose of calculating recovery if required.
Evaluation Procedure
Review data and determine the raw data for the spike sample analysis. Verify the calculation of the recoveries and verify results have been correctly reported.
Discussion
In order to properly assess spike sample analysis results, it is necessary for the reviewer to consider a variety of factors which could impact their outcome, such as:
- Matrix suppression effects. - Matrix enhancement effects. - Duplicate precision results. - Digestion efficiency. - Contamination. - Relative levels of analyte in spike and sample; for example, if the endogenous sample level is greater than 4 times the spike level the percent recovery results should not be considered accurate or used to judge the accuracy of the sample results.
Created By Steph Kexel SOP No: 09-033-09 Date Initiated: 12/96 Revision Date: 1/15/16 Page 96 of 97 The following guidelines are recommended for use in evaluating data usability when the spike recoveries do not fall within the required limits:
• If the spike recovery is out of range and the reported sample results are less than the method detection limit (MDL) then this data is acceptable for use.
• If the recovery is out of range and the reported sample levels are greater than the MDL, it should be reported in the project narrative.
• Results of the continuing calibration verification (CCV) should be considered when evaluating spike recoveries. Sample batch acceptance is usually based on results of the CCV rather than the matrix spike alone.
Created By Steph Kexel SOP No: 09-033-09 Date Initiated: 12/96 Revision Date: 1/15/16 Page 97 of 97 Field Quality Control (QC) and Other Quality Control Techniques
Objective, Definitions and Assessment:
Field QC consists of field blanks and field duplicates. Other types of QC samples include split samples, blind blanks, and blind spikes.
A field blank is DI water that has been "run through" all of the sampling equipment. The intent of a field blank is to monitor for contamination introduced by sampling personnel, although any laboratory introduced contamination will also be present.
A blind blank is bottled and preserved by the field group and sent as is to the laboratory. The purpose of a blind blank is to monitor for contamination introduced by the laboratory.
A blind spike is prepared by the field group, inorganic standards spiked into DI water. The purpose of the blind spike is to provide a QC sample to monitor the laboratory’s ability to reach CRDL's and/or the lab's ability to quantitatively recover an analyte.
A split sample is one that is divided between two laboratories. When analyzing a split sample it is important that the same methodology is used by both laboratories so that there is a basis for the comparison of the results.
Blanks and splits are useful as supporting evidence in the overall assessment of the survey. Blanks are samples of known composition and matrix. As such, they are useful in assessing a laboratory's performance independent of sample or method problems which may arise in a real sample.
Except in the case of a gross error, blanks and splits should not be the basis of accepting or rejecting data, but rather as additional evidence in support of conclusions arrived at by a review of the total data package. Blanks, spikes, and split sample results will often point out areas the reviewer needs to look at more carefully.
Created By Steph Kexel