Nc Denr/Dwq Laboratory Certification s2

NC DENR/DWQ LABORATORY CERTIFICATION

LABORATORY NAME: CERT #: PRIMARY ANALYST: DATE: NAME OF PERSON COMPLETING CHECKLIST (PRINT): SIGNATURE OF PERSON COMPLETING CHECKLIST:

Parameter: Total Phosphorus Method: EPA 365.1, Rev. 2.0 (1993) (Aqueous) Automated Colorimetry

EQUIPMENT: Automated continuous flow analyzer Acid-washed glassware Model: Wavelength: 650-660 or 880 nm Filters Hotplate Type: Pore Size: Water bath, 95°C Balance -- Analytical, capable of accurately weighing to the nearest 0.0001 g. Optional: Autoclave

ANALYSIS REAGENTS: See last page for reagent recipes

Sulfuric acid (H2SO4), 5 N Phenolphthalein indicator solution Standard phosphorus solution

Ammonium molybdate solution Sodium bisulfate (NaHSO3) solution Stock phosphorus solution

Antimony potassium tartrate solution Sulfuric acid (H2SO4), 11 N Acid wash water Combined reagent Ammonium persulfate Ascorbic Acid, 0.1M

PLEASE COMPLETE CHECKLIST IN INDELIBLE INK Please mark Y, N or NA in the column labeled LAB to indicate the common lab practice and in the column labeled SOP to indicate whether it is addressed in the SOP. L S GENERAL A O EXPLANATION B P What is the most recent review/revision date of the SOP? [15A NCAC Date: 1 2H .0805 (a) (7)] 2 Is there North Carolina data available for review? L S PRESERVATION and STORAGE A O EXPLANATION B P

Are samples preserved at time of collection with H2SO4 to pH of <2? 3 [40 CFR 136.3 Table II] Are samples iced to above freezing but ≤ 6 º C during transport? 4 [40 CFR 136.3 Table II and footnote 18] Is pH checked to document pH <2 upon receipt? 5 [40 CFR 136.3 Table II]

6 What action is taken if pH is >2?

Are samples refrigerated above freezing and ≤ 6°C during storage? 7 [40 CFR 136.3 Table II and footnote 18] Are samples analyzed within 28 days of collection? 8 [40 CFR 136.3 Table II] L S PROCEDURE – Calibration A O EXPLANATION B P What is your laboratory’s lower reporting limit? [15A NCAC 2H .0805 9 (a) (7) (I)] Total Phosphorus – EPA 365.1, Rev. 2.0 (1993) Page 2 of 4

Is a calibration curve consisting of at least three standards and a blank analyzed daily or a curve consisting of at least five standards analyzed annually? [15A NCAC 2H .0805 (a) (7) (I)] [EPA Method 10 365.1, Rev. 2.0 (1993), Section 10.1]

List the calibration standard concentrations:

Are calibration standards and calibration blanks processed the same 11 as samples? [EPA Method 365.1, Rev. 2.0 (1993), Section 10.2] Are standards analyzed in order of decreasing concentration? [EPA 12 Method 365.1, Rev. 2.0 (1993), Section 10.5] Does each standard curve have a correlation coefficient ≥0.995? 13 [NC WW/GW LC Policy] L S PROCEDURE – Sample Analysis A O EXPLANATION B P What sample volume is analyzed? [EPA Method 365.1, Rev. 2.0 14 (1993), Section 11.1.1] Is 1 ml of 11N sulfuric acid added? [EPA Method 365.1, Rev. 2.0 15 (1993), Section 11.1.1] Is 0.4 g ammonium persulfate added and the sample mixed? [EPA 16 Method 365.1, Rev. 2.0 (1993), Section 11.1.2] Is the mixture gently boiled for approximately 30-40 minutes or until 17 a final volume of about 10 mL is reached? [EPA Method 365.1, Rev. 2.0 (1993), Section 11.1.3] Is the sample cooled and diluted to approximately 50 ml? [EPA 18 Method 365.1, Rev. 2.0 (1993), Section 11.1.4] If the sample is not clear, is it filtered? [EPA Method 365.1, Rev. 2.0 19 (1993), Section 11.1.4] Are samples whose computed value is less than 5% of its immediate 20 predecessor rerun? [EPA Method 365.1, Rev. 2.0 (1993), Section 12.2] L S QUALITY ASSURANCE A O EXPLANATION B P Has a Method Detection Limit (MDL) been established? [EPA 21 Method 365.1, Rev. 2.0 (1993), Section 9.2.4] Is a second source standard (QCS) analyzed daily prior to sample analysis to verify the calibration? [EPA Method 365.1, Rev. 2.0 22 (1993), Section 10.7] [EPA Method 365.1, Rev. 2.0 (1993), Section 3.10] [NC WW/GW LC Policy] What acceptance criterion is used to evaluate the second-source 23 standard (QCS)? [EPA Method 365.1, Rev. 2.0 (1993), Section 10.7] What corrective action is taken if the second source standard (QCS) 24 recovery is outside of established control limits? [EPA Method 365.1, Rev. 2.0 (1993), Section 10.7] Is a reagent blank analyzed with each batch of samples? [EPA 25 Method 365.1, Rev. 2.0 (1993), Section 9.3.1] Is the reagent blank concentration less than or equal to ½ of the 26 lowest calibration standard concentration? [NC WW/GW LC Policy] What corrective action is taken if the reagent blank is not less than or 27 equal to ½ of the lowest calibration standard concentration? [15A NCAC 2H .0805 (a) (7) (F)] Are the calibration blank and mid-range standard (IPC) analyzed each day, prior to sample analyses, after every tenth sample and at 28 the end of the sample run? [EPA Method 365.1, Rev. 2.0 (1993), Section 9.3.4] Is the calibration blank acceptance criterion less than or equal to ½ 29 of the reporting limit? [NC WW/GW LC Policy] What corrective action is taken if the calibration blank is not less than 30 or equal to ½ of the reporting limit? [15A NCAC 2H .0805 (a) (7) (F)] What is the acceptance criterion for recovery of the mid-range 31 standard (IPC)? [EPA Method 365.1, Rev. 2.0 (1993), Section 9.3.4] Revised 01/2017 Total Phosphorus – EPA 365.1, Rev. 2.0 (1993) Page 3 of 4

What corrective action is taken if the mid-range standard (IPC) 32 recovery varies by greater than 10%? [EPA Method 365.1, Rev. 2.0 (1993), Section 9.3.4] Is a Laboratory Fortified Blank (LFB) analyzed with each set of 33 samples?] [EPA Method 365.1, Rev. 2.0 (1993), Sections 3.4 and 9.3.2] What is the acceptance criterion for LFB recovery? [EPA Method 34 365.1, Rev. 2.0 (1993), Section 9.3.2] What corrective action does the laboratory take if the LFB results are 35 outside of established control limits? [15A NCAC 2H .0805 (a) (7) (F)] Is a Matrix Spike (MS) analyzed at 10% frequency? [EPA Method 36 365.1, Rev. 2.0 (1993), Section 9.4.1] How is the MS prepared? [NC WW/GW LC Matrix Spike Technical 37 Assistance.]

What is the acceptance criterion for MS recovery? [EPA Method 38 365.1, Rev. 2.0 (1993), Section 9.4.2

What corrective action does the laboratory take if the MS results are 39 outside of established control limits? [NC WW/GW LC Policy] [EPA Method 365.1, Rev. 2.0 (1993), Section 9.4.3

At what frequency are duplicates and/or Matrix Spike Duplicates 40 (MSD) analyzed? [15A NCAC 2H .0805 (a) (7) (C)]

What is the acceptance criterion for duplicates and/or MS/MSD? [40 41 CFR Part 136.7 (c) (1) (viii)]

What corrective action does the laboratory take if the duplicate 42 and/or MS/MSD results are outside of established control limits? [15A NCAC 2H .0805 (a) (7) (F)] Is the data qualified on the Discharge Monitoring Report (DMR) or 43 client report if Quality Control (QC) requirements are not met? [NC WW/GW LC policy]

Analytical Reagents & Standards Prep:

Sulfuric acid 5 N : Slowly add 70 mL of conc. H2SO4 to approximately 400 mL of reagent water. Cool to room temperature and dilute to 500 mL with reagent water.

Sulfuric acid, 11 N : Slowly add 310 mL of conc. H2SO4 to approximately 600 2 4 mL distilled water. Cool and dilute to 1000 mL.

Antimony potassium tartrate solution: Weigh 0.3 g K(SbO)C4H4O6 · ½ H2O and dissolve in 50 mL reagent water in 100 mL volumetric flask, dilute to volume. Store at 4°C in a dark, glass-stoppered bottle.

Ammonium molybdate solution: Dissolve 4 g of (NH4)6Mo7O24 · 4H2O in 100 mL reagent water. Store in a plastic bottle at 4°C.

Ascorbic acid, 0.1 M : Dissolve 1.8 g of ascorbic acid in 100 mL of reagent water. This solution is stable for about a week if prepared with water containing no more than trace amounts of heavy metals and stored at 4°C.

Combined reagent: Mix the above reagents in the following proportions for 100 mL of the mixed reagent: 50 mL of 5N H 2SO4 (Section 7.2), 5 mL of 2 4 antimony potassium tartrate solution (Section 7.3), 15 mL of ammonium molybdate solution (Section 7.4), and 30 mL of ascorbic acid solution (Section 7.5). Mix after addition of each reagent. All reagents must reach room temperature before they are mixed and must be mixed in the order given. If turbidity forms in the combined reagent, shake and let stand for a few minutes until the turbidity disappears before processing. This volume is sufficient for a four hour operation. Since the stability of this solution is limited, it must be freshly prepared for each run. Note: A stable solution can be prepared by not including the ascorbic acid in the combined reagent. If this is done, the mixed reagent (molybdate, tartrate, and acid) is pumped through the distilled water line and the ascorbic acid solution (30 mL of 7.5 diluted to 100 mL with reagent water) through the original mixed reagent line.

Acid wash water: Add 40 mL of sulfuric acid solution (Section 7.7) to 1 L of reagent water and dilute to 2 L. (Not to be used when only orthophosphate is being determined).

Phenolphthalein indicator solution (5 g/L): Dissolve 0.5 g of phenolphthalein (CASRN 77-09-8) in a solution of 50 mL of isopropyl alcohol (CASRN 67-63-0) and 50 mL of reagent water.

Revised 01/2017 Total Phosphorus – EPA 365.1, Rev. 2.0 (1993) Page 4 of 4

Stock phosphorus solution: Dissolve 0.4393 g of predried (105°C for one hour) KH2PO4 in distilled water and dilute to 1000 mL. 1.0 mL = 0.1 mg P.

Standard phosphorus solution: Dilute 10 mL of stock phosphorus solution to 100 mL with distilled water. 1.0 mL = 0.01 mg P. Prepare an appropriate series of standards by diluting suitable volumes of standard or stock solutions to 100 mL with distilled water.

Additional Comments:

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Inspector: ______Date: ______

Revised 01/2017