Semi-Volatile Fluorinated Organic Compounds in Asian and Pacific Northwestern US Air Masses

AN ABSTRACT OF THE THESIS OF

Arkadiusz M. Piekarz for the degree of Master of Science in Chemistry presented on

March 28, 2007.

Title: Semi-volatile Fluorinated Organic Compounds in Asian and Pacific Northwestern

U.S. Air Masses.

Abstract approved:

Staci Simonich

Current studies suggest that perfluorinated organic compounds, such as fluorotelomer alcohols (FtOHs) in the troposphere, may be precursors of perfluorocarboxylic acids and perfluorosulfonates in remote regions. Fluorinated organic compounds were investigated in archived extracts collected from remote locations in

Okinawa, Japan (HSO) and Mount Bachelor, Oregon (MBO) during the springs of 2004

(MBO and HSO) and 2006 (MBO only). These high volume air samples were subjected to pressurized liquid extraction, concentrated, and analyzed by GC/MS. FtOHs were measured in both HSO and MBO air masses, though MBO had significantly higher concentrations. We identified fluorotelomer olefins (in HSO air) and 8:2 fluorotelomer acrylate (in MBO 2006 air) for the first time in published literature. N-Ethyl 3 perfluorooctane sulfonamide (N-EtFOSA), N-Methyl perfluorooctane sulfonamido ethanol (N-MeFOSE), and N-Ethyl perfluorooctane sulfonamido ethanol (N-EtFOSE) were measured in HSO and MBO air masses, but detected less frequently than FtOHs.

6:2 fluorotelomer acrylate, perfluorooctane sulfonamido acrylates, perfluorobutane sulfonamide, and perfluorobutane sulfonamido ethanol were not detected in any air samples from this study. For MBO 2006, the sources of fluorotelomer alcohols were investigated using HYSPLIT back trajectories, residual fluorinated product signatures, and correlations with semi-volatile organic compounds (SOCs). FtOH concentrations during MBO 2006 were not significantly correlated (p-value > 0.05) with the amount of time an air trajectory spent in a specific source region such as California, Washington,

Oregon, and Canada. Since FtOH concentrations were significantly correlated (p-value <

0.05) with each other, the average ratio of 6:2 FtOH to 8:2 FtOH to 10:2 FtOH during

MBO 2006 was calculated to be 1.0 (0.1) to 5.0 (0.7) to 2.5 (0.4), where the parenthesis represent 95% confidence intervals. Also, FtOH concentrations at MBO 2006 were positively correlated (p-value < 0.5) with gas-phase PAHs and PCBs and negatively correlated (p-value <0.05) with agricultural pesticides such as endosulfan. This suggests that FtOHs are coming mainly from urban sources. Atmospheric residence times from

MBO 2006 data for 6:2 FtOH, 8:2 FtOH, and 10:2 FtOH, based on a method using trace gas variability, were calculated to be 50, 80, and 70 days, respectively. Finally, gas/particle partitioning of semi-volatile flurochemicals was examined. 4

©Copyright by Arkadiusz M. Piekarz

March 28, 2007

Semi-volatile Fluorinated Organic Compounds in Asian and Pacific Northwestern U.S.

Air Masses

Arkadiusz M. Piekarz

A THESIS

submitted to

Oregon State University

in partial fulfillment of

the requirements for the

degree of

Master of Science

Presented March 28, 2007

Commencement June 2007 6

Master of Science thesis of Arkadiusz M. Piekarz presented on March 28, 2007.

APPROVED:

Major Professor, representing Chemistry

Chair of the Department of Chemistry

Dean of the Graduate School

I understand that my thesis will become part of the permanent collection of Oregon State

University libraries. My signature below authorizes release of my thesis to any reader upon request.

Arkadiusz M. Piekarz, Author 7

ACKNOWLEDGEMENTS

The author expresses thanks to Dupont for an unrestricted gift, EPA STAR program, and the NSF for CAREER GRANT ATM-0239823. Also thanks to Toby Primbs, Carin

Huset, and the Simonich lab for their expertise, and Drs Staci Simonich, Jennifer A.

Field, and Douglas F. Barofsky.

TABLE OF CONTENTS

Page

CHAPTER 1 INTRODUCTION ...... 1

CHAPTER 2 SEMI-VOLATILE FLUORINATED ORGANIC COMPOUNDS IN

ASIAN AND PACIFIC NORTHWESTERN U.S. AIR MASSES ...... 15

CHAPTER 3 CONCLUSION...... 87

BIBLIOGRAPHY...... 89

APPENDICES ...... 94

APPENDIX A: PCA ANALYSIS ON RATIOS FOR MBO 2006 ...... 95 APPENDIX B: PCA ANALYSIS ON INDIVIDUAL FTOH CONCENTRATIONS FOR MBO 2006...... 97

LIST OF FIGURES

Figure Page

2.1: MAP OF SAMPLING LOCATIONS (HSO AND MBO) AND SRIF BOXES FOR MBO...... 70

2.2: PCI SIM CHROMATOGRAMS...... 71

2.3: DENSITY PLOTS FROM 10-DAY BACK TRAJECTORIES FOR MBO 2004 SAMPLES...... 73

2.4: DENSITY PLOTS FROM10-DAY BACK TRAJECTORIES FOR MBO 2004 SAMPLES...... 74

2.5: FTENES, FTOHS, N-MEFOSE, N-ETFOSE, AND N-ETFOSA AIR 3 CONCENTRATIONS (PG/M ) FOR HSO 2004...... 79

3 2.6: FTOH, N-MEFOSE, N-ETFOSE, AND N-ETFOSA AIR CONCENTRATIONS (PG/M ) FOR MBO 2004...... 80

2.7: FTOH, 8:2 FTAC, N-MEFOSE, N-ETFOSE, AND N-ETFOSA AIR 3 CONCENTRATIONS (PG/M ) FOR MBO 2006...... 81

2.8: LOG[FTOH] VS 1/T FOR MBO 2006 SAMPLES...... 82

2.9: PCA BIPLOT USING AVERAGE FTOH RATIOS (6:2 FTOH/8:2 FTOH/10:2 FTOH) FROM CONSUMER PRODUCTS, MBO 2006, AND LITERATURE...... 83

2.10: PERCENT OF TOTAL CONCENTRATION IN THE GAS PHASE FOR FLUORINATED ORGANIC COMPOUNDS MEASURED AT HSO AND MBO 2004, AND MBO 2006...... 84

2.11: PLOT OF FRACTION OF FTOH IN PARTICLE PHASE,Φ, VERSUS1/T FOR MBO 2006 SAMPLES...... 85

2.12: COMPARISON OF MBO 2006 FTOH AIR CONCENTRATIONS WITH LITERATURE...... 86 10

LIST OF TABLES

Table Page

1.1: FLUORINATED ALKYL ANALYTE, ACRONYM, CHEMICAL STRUCTURE, VENDOR, AND PURITY INFORMATION...... 10

1.2: PHYSICAL CHEMICAL PROPERTIES OF SELECTED FLUORINATED ORGANIC CHEMICALS.12

1.3: RATIOS OF 6:2 FTOH/8:2 FTOH/10:2 FTOH FOR RESIDUAL FLUOROTELOMER -BASED COMMERCIAL PRODUCTS...... 13

1.4: DEGRADATION PRODUCTS FROM THE REACTION 8:2 FTOH WITH OH RADICAL SMOG CHAMBER STUDIES...... 14

2.1 : FLUORINATED ALKYL ANALYTE, ACRONYM, CHEMICAL STRUCTURE, VENDOR, AND PURITY INFORMATION...... 49

2.2: SAMPLE START DATES, AVERAGE SITE TEMPERATURES, SAMPLE VOLUMES, WIND SPEEDS, SUMS OF PRECIPITATION (∑PPT), AND SOURCE REGION IMPACT FACTORS (SRIFS, %) USING 4-DAY BACK TRAJECTORIES FOR HSO SPRING 2004...... 51

2.3: SAMPLE START DATES, AVERAGE SITE TEMPERATURES, SAMPLING VOLUMES, RATIOS (6:2 FTOH/8:2 FTOH/10:2 FTOH), AND SOURCE REGION IMPACT FACTORS (SRIFS, %) USING 10-DAY BACK TRAJECTORIES FOR MBO SPRING 2004. . 52

2.4: SAMPLE START DATES, AVERAGE SITE TEMPERATURES, SAMPLING VOLUMES, FTOH RATIOS (6:2 FTOH/8:2 FTOH/10:2 FTOH), AND SOURCE REGION IMPACT FACTORS (SRIFS, %) USING 10-DAY BACK TRAJECTORIES FOR MBO SPRING 2006...... 53 11

LIST OF TABLES (CONTINUED)

Table Page

2.5: FLUORINATED CHEMICAL, RETENTION TIMES (ON A 30 METER EC-WAX COLUMN), MOLECULAR WEIGHTS, AND IONS MONITORED FOR GC/MS ANALYSIS IN PCI AND NCI MODES...... 55

2.6: INSTRUMENTAL LIMIT OF DETECTIONS (LODS) FOR EVERY INSTRUMENT AND GC- COLUMN COMBINATION USED FOR GC/MS ANALYSIS...... 56

2.7. AVERAGE PERCENT RECOVERIES OF TARGET ANALYTES OVER THE ENTIRE METHOD.. 57

2.8. AVERAGE PERCENT RECOVERIES OF TARGET ANALYTES DURING CONCENTRATION STEP ONLY. ACETONE/HEXANE RECOVERIES USED IN PUF CONCENTRATION STEP. DCM (DICHLOROMETHANE)/EA(ETHYL ACETATE) USED IN FILTER AND XAD CONCENTRATION STEP...... 58

2.9: METHOD RELATIVE STANDARD ERRORS (RSES, %) FOR EACH ANALYTE...... 59

2.10: RELATIVE STANDARD ERRORS (RSES) OF A 10 PG STANDARD ON JEOL GC-MATE II USING EC-WAX COLUMN...... 60

3 2.11: AIR CONCENTRATIONS (PG/M ) OF FLUORINATED ORGANICS MEASURED DURING THE HSO SPRING 2004 CAMPAIGN...... 61

3 2.12: AIR CONCENTRATIONS (PG/M ) OF FLUORINATED ORGANICS MEASURED DURING THE MBO SPRING 2004 CAMPAIGN...... 62

3 2.13: AIR CONCENTRATIONS (PG/M ) OF FLUORINATED ORGANICS MEASURED DURING THE MBO SPRING 2006 CAMPAIGN...... 63 12

LIST OF TABLES (CONTINUED)

Table Page

2.14: SUMMARY OF AIR CONCENTRATIONS (AVERAGE VALUES, RANGE, AND FOD) OF FLUORINATED ORGANIC COMPOUNDS MEASURED DURING THE HSO AND 3 MBO 2004, AND MBO 2006 SAMPLING CAMPAIGNS , PG/M (ΣGAS PHASE AND PARTICULATE PHASE)...... 65

2.15: SUMMARY OF AIR CONCENTRATIONS (AVERAGE VALUES) OF FLUORINATED 3 ORGANIC COMPOUNDS REPORTED IN LITERATURE, PG/M (ΣGAS PHASE AND PARTICULATE PHASE)...... 66

2.16: CORRELATION MATRIX FOR FLUORINATED ORGANIC COMPOUND CONCENTRATIONS (PARTICLE AND GAS PHASE) IN THE MBO 2006 SAMPLES (SIGNIFICANT CORRELATIONS ARE ASSIGNED P-VALUES <0.05)...... 67

2.17: AVERGAE RATIOS OF 6:2 FTOH/8:2 FTOH/10:2 FTOH FOR RESIDUAL FLUOROTELOMER-BASED COMMERCIAL PRODUCTS COMPARED TO MBO 2006 AND LITERATURE VALUES...... 68

2.18. R VALUES AND P-VALUES FOR CORRELATIONS BETWEEN FTOHS AND SOCS IN MBO 2006...... 69

CHAPTER 1 INTRODUCTION

Fluorochemicals are stable (C-F bond energy ~110 kcal/mol) and chemically inert. They can repel both water and oil (act as surfactants), have a low surface tension, and are used as intermediates in polymerization processes to form consumer products such as Teflon® or Scotchguard®1, 2. They are intermediates used in the synthesis of lubricants, paints, inks, stain-repellents, water-repellents, and varnishes2, 3. Table 1.1 shows the chemical names, acronyms, structures, vendors, and purities of each target analyte investigated in this research.

Physical Chemical Properties. The Table 1.2 shows PL, log KOA, log KAW values from published literature for FtOHs, N-EtFOSA, N-MeFOSE, and N-EtFOSE 4-7. Not listed in

Table 1.2, log Kaw values for 8:2 Ftene and 10:2 Ftene were calculated to be 3.45 and

4.07 respectively using polyparametric linear free energy relationships 7.

Vapor pressure (PL), in units of Pa, describes the saturated pressure of an analyte

in the gas phase at a given temperature. Relatively volatile compounds (not semi-

8 volatile) have a vapor pressure from 1 to 10 Pa . KAW is the unitless air-water partition coefficient. KAW is equal to pi/Cw where pi is the equilibrium vapor pressure of a

compound above a pure mixture and Cw is the aqueous solubility of a compound. KOA, a unitless quantity, is the partition coefficient between n-octanol and air.

The table does not represent a comprehensive literature survey, but it does contain

the most recently published studies on the physical-chemical properties of

fluorochemicals and shows the discrepancies between measured values for certain

physical chemical properties. For example, vapor pressure for 8:2 FtOH varies from 227 2

Pa (very volatile) at 250C (GC-retention time method) to 3 Pa (almost semi-volatile) at

0 21 C (gas saturation method). Log KAW values vary from 1.31 (not likely to undergo wet

deposition) to -0.53 (may undergo wet deposition) for 8:2 FtOH at 250C.

Indirect/Direct Sources of FtOHs, Ftenes, and C8-FOS (N-MeFOSE, N-EtFOSE, N-

1, 2, 9, 10 EtFOSA) species . C8-FOS species were residuals common in the electrochemical

fluorination production of perfluorooctanesulfonyl fluoride (POSF)9. Since 3M has phased out the production of its line of C8 fluorochemicals in 2002, indirect sources

2 likely dominate the levels of C8-FOS species in the environment . N-MeFOSE-based materials are used in surface treatment products in home products (e.g. carpets), while N-

EtFOSE-based materials are associated paper protection products (e.g. food packaging)1.

Thus residual N-MeFOSE and N-EtFOSE not incorporated into the polymeric material can possibly volatilize from consumer products into air3.

Fluorotelomer-based products have been produced since the 1970s2. Telomer A

(F (CF2CF2)nCH2CH2I is a basic raw material for the manufacture of FtOHs, fluorotelomer olefins, and fluorotelomer iodides. Telomer A is manufactured in one site in the United State, one site in Germany, and two sites in Japan2. The subsequent FtOHs or fluorotelomer iodides produced from Telomer A are used to make an acrylate

monomer (mostly 8:2 FtAc), a polymeric building block for more than 80 percent of

fluorotelomer-based products in the world1, 2. Fluorotelomer-based products continue to

be used in the same applications as POSF-based products and residual volatilization from

fluorotelomer-bases products is also possible1. 3

Using purge and trap experiments, Mabury et al measured residual

concentrations of FtOHs and N-MeFOSE in various fluorinated polymeric and surfactant

materials used in commercial and industrial applications1. The list of products included:

Teflon® Advance Rug and Carpet cleaner, Zonyl FSO 100, Zonyl FSE, Motomaster

Windshield Washer with Teflon®, and Scotchgard® Rug and Carpet protector. N-

MeFOSE was only detected in the Scotchgard® product. The Telomer-based fluorinated materials contained of 0.04 to 4% residual FtOHs on a dry mass basis. Thus ratios of 6:2

FtOH to 8:2 FtOH to 10:2 FtOH were calculated for theses fluorotelomer-based products.

Table 1.4 shows calculated 6:2 FtOH, 8:2 FtOH, and 10:2 FtOH ratios for fluorinated- based products using data from Mabury et al1. The ratio represents the mass of each

FtOH relative to the FtOH in lowest mass in a given fluorinated material. It is estimated that there are approximately 200 tons/year FtOH and fluorotelomer olefin residuals contained in fluorotelomer-based products made from 2000-20022. Finally, it is

important to note that Teflon® is just a label that Dupont puts on consumer products.

Teflon® does not designate one specific ratio of FtOHs for products that contain

Teflon®. For example, Table 1.3 shows different ratios observed for Teflon® Advance

Rug and Carpet cleaner and Motomaster Windshield Washer with Teflon®.

The primary purpose of the ammonium perfluorooctanoate, (APFO) and ammonium perfluorononanoate (APFN) salts is to aid processing in fluoropolymer production (e.g. polytetrafluoroethylene or polyvinyl fluoride) 2. APFN is produced in

Japan from the oxidation of a mixture of fluorotelomer olefins (the principal raw material 4

is 8:2 Ftene) 2. APFO is produced in the United States from the oxidation of fluorotelomer iodides (the principle raw material is perfluorooctyl iodide) 2.

2002 data shows there are 33 fluoropolymer manufacturing sites in the world:

eight in North America; seven in Japan; seven in China; seven in Europe; two in Russia;

one in India2. In 2000, 85 percent of fluoropolymer manufactured was from APFO2. To our knowledge, there are no fluoropolymer manufacturing sites in the Pacific Northwest of the United States.

Environmental and Toxicological Concerns. Perfluorooctane sulfonate (PFOS) and long- chain perfluorinated carboxylic acids (PFCAs) have been detected in mammals across the

North American Arctic, in urban, coastal, and remote areas of Europe and Asia, in North

American precipitation, and in the North Atlantic Sea11-19. However, PFOS and PFCAs are relatively nonvolatile, due to their ionic nature, and the mechanism by which they are transported to remote locations is not well understood2. In addition, there is some evidence that PFOS and long-chain perfluorinated carboxylic acids (PFCAs) bioconcentrate, with mammals in higher trophic levels having the highest concentrations12. A study of rainbow trout showed that the bioconcentration of PFCAs

increased with fluoroalkyl chain length, with bioconcentration factors (BCFs) ranging

from 4.0 to 23, 000 L/kg20.

Due to toxicological studies of PFOA and its presence in human sera, the United

States Environmental Protection Agency (EPA) conducted a risk assessment of PFOA in

2003 and concluded that it is a “suggestive carcinogen21.” In vivo studies of rat liver cells show that PFCAs, known peroxisome proliferators, may be carcinogens in rats by 5

inhibiting gap junctional intercellular communication22. Male fatheads exposed to increasing levels of PFOA had larger livers, while female fatheads exposed to increasing levels of PFOA had a reduction of cumulative egg production23. Thus understanding the sources of these compounds, their possible atmospheric intermediates, and the atmospheric transport and deposition of these intermediates to remote and sensitive ecosystems is vital.

6:2, 8:2, and 10:2 fluorotelomer alcohols (FtOHs), N-methyl perfluorooctane

sulfonamidoethanol (MeFOSE), N-ethyl perfluorooctane sulfonamidoethanol (EtFOSE),

and N-ethyl perfluorooctane sulfonamide (EtFOSA) have been reported in the

atmosphere near urban areas in the United States, Germany, Canada, as well as remote

areas in the North Atlantic Ocean and the Canadian Archipelago3, 24-28. 8:2 FtOH, 10:2

FtOH, MeFOSE, and EtFOSE also exhibit gas particle-partitioning in the atmosphere25-28.

Smog chamber studies suggest that these fluorinated organic compounds may undergo regional and long-range atmospheric transport due to their relatively slow rate of reaction

with hydroxyl radical in the atmosphere. These smog chamber experiments measured the

atmospheric lifetimes of FtOHs and N-methylperfluorobutanesulfonamide (N-MeFBSA)

to be at least 20 days and suggest that, regardless of chain length, FtOHs and

perfluorosulfonamides degrade at the same rate into a series of homolog

perfluorosulfonates and PFCAs29-34.

Smog chamber experiments and atmospheric lifetimes29. Relative rate techniques were

used to measure the reaction kinetics of OH radicals with 4:2 FtOH, 6:2 FtOH, and 8:2

FtOH 29. The smog chamber consisted of a 140-L Pyrex reactor attached to a fourier- 6

transform infared spectroscopy (FTIR) spectrometer and 22 fluorescent black lamps29.

The experiments were conducted at 296 K in 700 torr of N2 or air. Photolysis of 100-300

torr of CH3ONO generated OH radicals in the chamber. Control experiments for direct

photolysis, dark reactions, and heterogeneous chemistry inside the smog chamber were

negative 29. Loss of FtOHs and reference compounds were monitored by (FTIR). FtOHs were monitored over the 3550-3650 cm-1 (O-H stretch).

The rate of reaction with rate constant, kFtOH (second-order rate constant), was

measured relative to the rate of reaction of OH radical to a reference compound with a

29 known rate constant, kreference . The slope, kFtOH/kreference, from the linear plots of ln

([FtOH]t0/[FtOH]t versus ln ([Reference]t0/[Reference]t is used to calculate the

atmospheric lifetime. An average kFtOH for a specific FtOH was measured relative to two reference compounds, C2H2 and C2H4. The atmospheric lifetime was calculated using

known values of atmospheric lifetime and rate constant from the reaction of CHCCl3 with

OH radical and the average kFtOH value. Regardless of chain length, the atmospheric lifetime of FtOHs was measured to be 20 days29.

In this study of fluorotelomer alcohol atmospheric lifetimes, Ellis et al. argued indirect photolysis, mainly reaction OH radical, is the main scavenger of FtOHs in air29.

Pointing to previous studies and theoretical considerations, they argued that other atmospheric processes, such as dry/wet deposition or direct photolysis, play minor roles in the atmospheric loss and degradation of FtOHs. It is important to note that their measurement of the atmospheric lifetime is an underestimation of the true value since it neglects atmospheric processes such as wet/dry deposition and particle/gas partitioning. 7

Smog chamber experiments: atmospheric degradation products from the indirect

photolysis of FtOHs. An almost identical experimental setup, described in the previous

section, was used to measure the degradation products of FtOHs from reaction with OH

radical35. The products (and the percentage of 8:2 FtOH converted to the specific products from the indirect photolysis of 8:2 FtOH) are shown in Table 1.4.

According to the proposed degradation mechanism of FtOHs, the PFCAs products are formed from reactions with ROx/HOx radicals. Moreover, the presence of NOx

32 species, that compete with ROx/HOx radicals, limits the formation of PFCAs . Thus the formation of PFCAs from the reaction of FtOHs with ROx/HOx radicals in air should be favored in remote areas where NOx levels are low. The formation of PFCAs from the 8:2

FtOH with OH radical was approximately 3 percent of the initial concentration of 8:2

FtOH. Smog chamber experiments with MeFBSE and MeFBSA also show that

perfluorinated sulfonamides undergo indirect photolysis in a similar ROx/HOx mechanism30, 34. From the MeFBSE and MeFBSA smog chamber studies, the formation of PFOS and PFOA from the original concentration of MeFOSE and EtFOSA is expected

to be 1 to 10% respectively33.

The smog chamber products in Table 1.4 have been found to exist in air. PFCAs, fluorotelomer carboxylic acids (FtCAs), and fluorotelomer unsaturated carboxylic acids

(FtUCAs) have been detected in rain events in Canada. In one rain event, Tomy et al.

measured FtCAs and FtUCAs at low parts-per-trillion (ppt) levels19. PFCAs were not

detected. Perfluorooctanoic acid, perfluoroheptanoic acid, perfluorohexanoic acid,

perfluoropentanoic acid, and perfluorobutanoic acid were also measured at concentrations 8

less than 0.5 to 3.2 ng/L in Canadian precipitation samples collected in three remote

sites36. In another precipitation study at a rural site in British Colombia, FtCAs and

FtUCAs were detected at less than 0.1 ng/L, while perfluorooctanoic acid,

perfluoroheptanoic acid, perfluorohexanoic acid, perfluoropentanoic acid, and

perfluorobutanoic acid were also measured at concentrations less than 6.1 ng/L18.

Ocean and Marine aerosols. Given the use of organic fluorinated chemicals spanning 50 year and their possible accumulation in oceanic waters, global transport via marine aerosol or oceanic transport is another possible explanation for presence of perfluorinated surfactants in the Arctic2. Measurements of the chemical compositions of aerosols at altitudes of 5 to 19 kilometers show that aerosols in the upper troposphere usually contain more organic material than sulfate37. Moreover, studies suggest that the formation of

fluorinated surfactant aerosols at the ocean surface may occur following an inverted

micelle model38-40. According to this model, fluorinated surfactants, such as PFOA, may undergo long-range transport with their hydrophobic tail exposed to the atmosphere and their polar head groups situated inside the ionic aqueous core of the aerosol40. There is also evidence that hexachlorocyclohexanes, a semi-volatile organic compound, may undergo aquatic transport to the Arctic41-43.

Present Study. Fluorinated organic compounds were measured in archived extracts collected from two remote locations, Okinawa, Japan (HSO) and Mount

Bachelor (MBO), Oregon, during the Springs of 2004 (for HSO and MBO) and 2006 (for

MBO only)44, 45. We investigated source regions of fluorinated organic chemicals using

HYSPLIT 4-day (for HSO) and 10-day (for MBO) back trajectories46; correlations with 9

other semi-volatile organic compounds (SOCs); residual fluorinated product signatures1; the types of fluorinated organic compounds detected and their concentrations were

compared in western North American and Asian air masses. Finally, gas/particle

partitioning of fluorinated organic compounds was investigated and the atmospheric

residence times of individual FtOHs were calculated using a trace gas variability method

developed by Junge47. 10

Table 1.1: Fluorinated alkyl analyte, acronym, chemical structure, vendor, and purity information. Purity Analyte Name Acronym Chemical Structure Vendor %

CF2 CF2 CF2 CF2 CH2 Perfluorooctane F C CF CF CF CH 8:2 Ftene 3 2 2 2 Aldrich 99 ethylene

CH Perfluorodecane CF2 CF2 CF2 CF2 CF2 2 10:2 Ftene F3C CF2 CF2 CF2 CF2 CH SynQuest 99 ethylene

CH Perfluorododecane CF2 CF2 CF2 CF2 CF2 CF2 2 12:2 Ftene F3C CF2 CF2 CF2 CF2 CF2 CH2 SynQuest 99 ethylene

Perfluorohexane ethyl CH 6:2 FtAc CF2 CF2 CF2 CH2 C 2 Aldrich 97 acrylate CF3 CF2 CF2 CH2 O CH

Perfluorooctane ethyl CH 8:2 FtAc CF2 CF2 CF2 CF2 CH2 C 2 Aldrich 97 acrylate CF3 CF2 CF2 CF2 CH2 O CH

Perfluorobutane CF2 CF2 CH2OH 4:2 FtOH F3C CF2 CH2 Oakwood 99 ethanol

Perfluorohexane CF2 CF2 CF2 CH2OH 6:2 FtOH F3C CF2 CF2 CH2 Aldrich 97 ethanol

CF2 CF2 CF2 CF2 CH2OH Pefluorooctane F C CF CF CF CH 8:2 FtOH 3 2 2 2 2 Oakwood 99 ethanol

CF2 CF2 CF2 CF2 CF2 CH2OH Perfluordecane F C CF CF CF CF CH 10:2 FtOH 3 2 2 2 2 2 SynQuest 96 ethanol

O N-Ethyl CF2 CF2 CF2 CF2 F 3C CF2 CF2 CF2 S CH2CH3 perfluorooctane N-EtFOSA NH ABCR >84 sulfonamide O

O N-Methyl CF2 CF2 CF2 CF2 perfluorooctane N- F3C CF2 CF2 CF2 S CH2CH2OC(O)CH=CH2 N 3M >94 sulfonamido ethyl MeFOSEA O acrylate CH3

O N-Ethyl CF2 CF2 CF2 CF2 perfluorooctane F3C CF2 CF2 CF2 S CH2CH2OC(O)CH=CH2 N-EtFOSEA N Acros >90 sulfonamido ethyl O acrylate CH2CH3

Table 1.1 (Continued): Fluorinated alkyl analyte, acronym, chemical structure, vendor, and purity information.

Analyte Purity Name Acronym Chemical Structure Vendor % N-Methyl O CF2 CF2 CF2 CF2 perfluorooctane F3C CF2 CF2 CF2 S CH2CH2OC(O)C(CH3)=CH2 N- sulfonamido N 3M >88 MeFOSEMA O ethyl CH3 methacrylate O N-Ethyl CF2 CF2 CF2 CF2 perfluorooctane F 3C CF2 CF2 CF2 S CH2CH2OC(O)C(CH3)=CH2 N sulfonamido N-EtFOSEMA O Acros >90

ethyl CH2CH3 methacrylate O CF2 CF2 N-Methyl F 3C CF2 S CH3 perfluorobutane N-MeFBSA NH 3M >98 O sulfonamide

O N-Methyl CF2 CF2 perfluorobutane F 3C CF2 S CH2CH2OH N-MeFBSE N 3M >98 sulfonamido O ethanol CH3

O N-Methyl CF2 CF2 CF2 CF2 perfluorooctane F3C CF2 CF2 CF2 S CH2CH2OH N-MeFOSE N 3M >72 sulfonamido O ethanol CH3 O N-Ethyl CF2 CF2 CF2 CF2 F C CF CF CF S CH CH OH perfluorooctane 3 2 2 2 2 2 N-EtFOSE N 3M >84 sulfonamido O ethanol CH2CH3

CF2 CF2 CF2 CH2OH Perfluoroheptane a F3C CF2 CF2 CF2 Aldrich 98 methanol PDFO a Internal Standard 12

Table 1.2: Physical chemical properties of selected fluorinated organic chemicals.

Physical Chemical Properties log Compound P , Pa P , Pa log K , log K , log K , L L P , Pa P , Pa AW AW OA K , 250C 250C L L 250C 250C 250C OA 250C 489 4:2 FtOH 1670 992 --- 1.83 -1.52 4.80 3.26 @350C 50 108 6:2 FtOH 876 713 1.66 -0.56 5.26 3.56 @350C @350C 2 8:2 FtOH 227 254 3 @210C 1.31 -0.53 5.56 4.17 @210C 0.7 14 10:2 FtOH 53 144 ------4.83 @350C @350C N-EtFOSA 7.0 ------5.86 N-MeFOSE 0.7 ------6.78 N-EtFOSE 0.35 ------7.09 Reference 6 4 5 5 6 7 7 6 Poly- Poly- GC- Headspace- paramter paramter GC- Boiling- Gas- Gas retention GC with linear free linear free retention Method point Phase saturation time phase ratio energy energy time method NMR method method variation relationships relationships method (pp- LFER) (pp- LFER) *Extrapolate No Yes Yes No Yes ------Yes

--- Not Applicable *Extrapolation of experimental data from high temperatures to environmentally relevant temperatures (e.g. 250C). 13

Table 1.3: Ratios of 6:2 FtOH/8:2 FtOH/10:2 FtOH for residual fluorotelomer-based commercial products1.

Ratio Integers Material 6:2 FtOH 8:2 FtOH 10:2 FtOH Polyfox-L-diol 1.0 25 13 Teflon® Advance 1.0 3.5 1.9 Zonyl FSO 100 3.7 2.0 1.0 Zonyl FSE 6.2 5.5 1.0 Motomaster Windshield 5.3 3.7 1.0 Washer

Ratio represents concentration of FtOH relative to the FtOH of lowest concentration measured in a product. 14

Table 1.4: Degradation products from the reaction 8:2 FtOH with OH radical smog chamber studies35.

Percent of 8:2 FtOH Compound Class Specific Compound Name converted to compound perfluorononanoic acid 1.6% perfluorooctanoic acid 1.5% perfluoroheptanoic acid 0.32% Perfluorinated Acids perfluorohexanoic acid 0.24% perfluoropentanoic acid 0.10% perfluorobutanoic acid <0.1% perfluoropropionic acid <0.1% trifluoroacetic acid <0.1% Fluorotelomer Carboxylic Acids 8:2 FtCA (C8F17CH2COOH) 26% Telomer Aldehydes 8:2 FtAL (C8F17CH2CHO) 6% Perfluoroaldehydes C8 PFAL (C8F17CH2CHO) 21% Odd Telomer Alcohols 8:1 FtOH 3.9% Unreacted FtOH 8:2 FtOH 6% Single Carbon Products COF2, CF3OH, CO2 <45.6%

CHAPTER 2 SEMI-VOLATILE FLUORINATED ORGANIC COMPOUNDS IN

ASIAN AND PACIFIC NORTHWESTERN U.S. AIR MASSES 16

Semi-volatile Fluorinated Organic Compounds in Asian and

Pacific Northwestern U.S. Air Masses

Arkadiusz M. Piekarz1, Toby Primbs1, Jennifer A. Field2, Douglas F. Barofsky1, and

Staci Simonich1, 2*

1Department of Chemistry, Oregon State University, Corvallis, Oregon

2Department of Environmental and Molecular Toxicology, Oregon State University,

Corvallis, Oregon

*Corresponding Author

Abstract

Current studies suggest that perfluorinated organic compounds, such as fluorotelomer alcohols (FtOHs) in the troposphere, may be possible precursors of perfluorocarboxylic acids and perfluorosulfonates in remote Arctic regions. Fluorinated organic compounds were investigated in archived extracts collected from remote locations in Okinawa, Japan (HSO) and Mount Bachelor, Oregon (MBO) during the springs of 2004 (MBO and HSO) and 2006 (MBO only). These high volume air samples were subjected to pressurized liquid extraction, concentrated, and analyzed by GC/MS.

FtOHs were measured in both HSO and MBO air masses, though MBO had significantly higher concentrations. To the best to our knowledge, we identified fluorotelomer olefins

(in HSO air) and 8:2 fluorotelomer acrylate (in MBO 2006 air) for the first time in published literature. N-Ethyl perfluorooctane sulfonamide (N-EtFOSA), N-Methyl

perfluorooctane sulfonamido ethanol (N-MeFOSE), and N-Ethyl perfluorooctane

sulfonamido ethanol (N-EtFOSE) were measured in HSO and MBO air masses, but

detected less frequently than FtOHs. 6:2 fluorotelomer acrylate, perfluorooctane

sulfonamido acrylates, perfluorobutane sulfonamide, and perfluorobutane sulfonamido

ethanol were not detected in any air samples from HSO or MBO. For MBO 2006, the

sources and fate of fluorotelomer alcohols were investigated using HYSPLIT back

trajectories, residual fluorinated product signatures, and correlations with semi-volatile

organic compounds (SOCs). FtOH concentrations during MBO 2006 were not

significantly correlated (p-value > 0.05) with the amount of time an air trajectory spent in

a specific source region such as California, Washington, Oregon, and Canada. Since 18

FtOH concentrations were significantly correlated (p-value < 0.05) with each other, the average ratio of 6:2 FtOH to 8:2 FtOH to 10:2 FtOH during MBO 2006 was calculated to be 1.0 (0.1) to 5.0 (0.7) to 2.5 (0.4), where the parenthesis represent 95% confidence intervals. Also, FtOH concentrations at MBO 2006 were positively correlated (p-value <

0.5) with gas-phase PAHs and PCBs and negatively correlated (p-value <0.05) with agricultural pesticides such as endosulfan. This suggests that FtOHs are coming from urban, not agricultural regions. Atmospheric residence times from MBO 2006 data for

6:2 FtOH, 8:2 FtOH, and 10:2 FtOH, based on a method using trace gas variability, were calculated to be 50, 80, and 70 days, respectively. Finally, gas/particle partitioning was examined for FtOHs, N-EtFOSA, N-MeFOSE, and N-EtFOSE.

Introduction

Fluorochemicals are stable (C-F bond energy ~110 kcal/mol) and chemically inert. They repel both water and oil (act as surfactants), have a low surface tension, and are used as intermediates in polymerization processes to form consumer products such as

Teflon® or Scotchguard®1, 2. They are intermediates used in the synthesis of lubricants, paints, inks, stain-repellents, water-repellents, and varnishes2, 3. Table 2.1 shows the chemical names, acronyms, structures, vendors, and purities of each target analyte investigated in this research.

Perfluorooctane sulfonate (PFOS) and other long-chain perfluorinated carboxylic acids (PFCAs) have been detected in mammals across the North American Arctic, in urban, coastal, and remote areas of Europe and Asia, in North American precipitation, and in the North Atlantic Sea11-19. However, PFOS and PFCAs are relatively nonvolatile, 19 due to their ionic nature, and the mechanism by which they are transported to remote locations is not well understood2. In addition, there is some evidence that PFOS

bioconcentrates, with mammals in higher trophic levels having the highest

concentrations12. A study of rainbow trout showed that the bioconcentration of PFCAs

increased with fluoroalkyl chain length, with bioconcentration factors (BCFs) ranging

from 4.0 to 23, 000 L/kg20.

Due to toxicological studies of PFOA and its presence in human sera, the United

States Environmental Protection Agency (EPA) conducted a risk assessment of PFOA in

2003 and concluded that it is a “suggestive carcinogen21.” In vivo studies of rat liver cells show that PFCAs, known peroxisome proliferators, may be carcinogens by inhibiting gap junctional intercellular communication22. Male fathead minnows exposed to increasing levels of PFOA had larger livers, while female fathead minnows exposed to increasing levels of PFOA had a reduction of cumulative egg production23. Thus understanding the sources of these compounds, their atmospheric intermediates, and the atmospheric transport and deposition of these intermediates to remote and sensitive ecosystems is important.

6:2, 8:2, and 10:2 fluorotelomer alcohols (FtOHs), N-methyl perfluorooctane

sulfonamidoethanol (MeFOSE), N-ethyl perfluorooctane sulfonamidoethanol (EtFOSE),

and N-ethyl perfluorooctane sulfonamide (EtFOSA) have been reported in the

atmosphere near urban areas in the United States, Germany, Canada, as well as remote

areas in the North Atlantic Ocean and the Canadian Archipelago3, 24-28. 8:2 FtOH, 10:2

FtOH, MeFOSE, and EtFOSE also exhibit gas particle-partitioning in the atmosphere25-28. 20

Smog chamber studies suggest that these fluorinated organic compounds may undergo regional and long-range atmospheric transport due to their relatively slow rate of reaction

with hydroxyl radical in the atmosphere. These smog chamber experiments measured the

atmospheric lifetimes of FtOHs and N-methylperfluorobutanesulfonamide (N-MeFBSA)

to be at least 20 days and suggest that, regardless of chain length, FtOHs and

perfluorosulfonamides degrade into a series of homolog perfluorosulfonates and

PFCAs29-34.

Given the use of organic fluorinated chemicals and their discharge into ocean water over the past 50 years, global transport via marine aerosol or oceanic transport is another possible explanation for the presence of perfluorinated surfactants in the Arctic2.

Measurements of the chemical compositions of aerosols at altitudes of 5 to 19 kilometers show that aerosols in the upper troposphere typically contain more organic material than sulfate37. Moreover, studies suggest that the formation of fluorinated surfactant aerosols at the ocean surface may occur following an inverted micelle model38-40. According to this model, fluorinated surfactants, such as PFOA, may undergo long-range transport with their hydrophobic tail exposed to the atmosphere and their polar head groups situated inside the ionic aqueous core of the aerosol40. There is also evidence that SOCs such as hexachlorocyclohexanes may undergo aquatic transport to the Arctic41-43.

In the present study, fluorinated organic compounds were measured in archived high-volume air samples collected from two remote locations, Okinawa, Japan (HSO) and Mount Bachelor (MBO), Oregon, during the Springs of 2004 (HSO and MBO) and

2006 (MBO only)44, 45. We investigated source regions of fluorinated organic chemicals 21 using HYSPLIT 4-day (HSO) and 10-day (MBO) back trajectories46; residual fluorinated

product signatures1 and correlations with other semi-volatile organic compounds (SOCs); the types of fluorinated organic compounds detected, and their concentrations, were compared in western North American and Asian air masses. Finally, gas/particle partitioning of fluorinated organic compounds was investigated and the atmospheric residence time of individual FtOHs were calculated using a trace gas variability method developed by Junge47.

Experimental Details

Chemicals, Sampling Media, and Materials. Target analytes and internal standards were either purchased from Sigma-Aldrich Corp. (St. Louis, MO), Oakwood Products, Inc.

(West Columbia, SC), Wellington Laboratories (Ontario, Canada), ABCR GmbH & Co

KG (Germany), Acros Organics (Belgium), and SynQuest Laboratories, Inc. (Alachua,

FL) or donated by the 3M Corp (St. Paul, MN). Working solutions and standards were prepared by weighing out pure analytes on a calibrated mass balance and subsequently diluting them with ethyl acetate (Optima-grade). Target analytes and internal standards were stored at 4 0C prior to their use. Optima-grade solvents were purchased from Fisher

Scientific (Fairlawn, NJ).

The modified high volume air sampler and polyurethane foam (PUF) (3” long x

3” diameter foam) were purchased from Tisch Environmental Inc. (Cleves, OH). 20 by

25.4 cm Whatman quartz-fiber filters (QFFs) and Amberlite XAD-2 (polystyrene divinyl

benzene) resin were purchased from VWR International (Westchester, PA) and Supelco

(Belafonte, PA), respectively. Pressurized liquid extraction (PLE) and extract 22 concentration were performed using Accelerated Solvent Extraction (ASE-300) (Dionex,

California) and the Turbovap® II (Caliper Life Sciences, Massachusetts), respectively.

Sampling Sites and Sample Collection. Eighteen 24-hour air samples (600-800 m3) were collected from March 22 through May 2, 2004 at the HSO Station Observatory (HSO) located 60 meters above sea level on the northwest coast of Okinawa, Japan (26.80N,

128.20E) (see Figure 2.1 for a map of the sample locations)45. HSO is an established site for measuring the outflow of atmospheric pollutants, including SOCs and mercury, from

Eurasia45, 48. Six 24-hour air samples (600-800 m3) were collected from April 22 through

July 21, 2004 and Thirty-four 24-hour air samples (600-800 m3) were collected from

April 23 through May 13, 2006 at Mount Bachelor Observatory (MBO). MBO is located on a mountaintop, 180 km east of the Pacific Ocean, in the Cascade region of central

Oregon (43.980N 121.690W 2700 masl) (see Figure 2.1). MBO is a relatively new site for studying trans-Pacific atmospheric transport49, 50. Start sample dates, air sample volumes, and other meteorological data for HSO 2004, MBO 2004, and MBO 2006 are shown in Tables 2.2, 2.3, and 2.4, respectively.

The high volume air sampler consisted of two QFFs to collect particulate matter

and a PUF-XAD-PUF sandwich to collect gas phase compounds. The back PUF was

used to assess analyte breakthrough during air sampling. Previous research groups have

used similar high volume air sampling approaches to measure fluorinated organic

compounds in outdoor air3, 5, 24. Sample flow rate calibration was performed using an

orifice manometer kit (Tisch Environmental Inc., Cleves, Ohio). The flow rate was 23 further confirmed using an anemometer (Extech, Massachusetts) during approximately 50 percent of the sampling events.

QFFs were baked at 350 0C for 12 hours prior to use, while XAD and PUF were

cleaned using PLE with dichloromethane and ethyl acetate and then dried under vacuum

overnight. All samples were stored at -20 0C in aluminum foil and solvent-rinsed/baked air-tight glass jars prior to deployment in the field and after sample collection. Samples were transported by commercial airplane (from HSO) or by automobile (from MBO) in coolers filled with blue ice to the laboratory.

Sample Extraction and Concentration. After being brought to room temperature in

sealed jars, the QFF, PUF, and XAD were inserted into 34, 66, or 100 mL ASE cells,

respectively. The XAD and QFFs were extracted with ethyl acetate, followed by dichloromethane45. The PUF was extracted using a 75:25 hexane:acetone mixture45. The extraction conditions were: 100 0C; 5 min. static time; 100% Flush; 1 Static Cycle; 240 sec. purge time. The extracts were concentrated to 600 µL using the Turbovap® II (and solvent exchanged to ethyl acetate for the PUF), followed by gentle blow down to 300 µL using ultra-pure nitrogen45.

Method Recovery Experiments. The analytical method was validated for the

fluorochemicals listed in Table 2.1 by performing spike and recovery experiments on the

PUF, XAD resin, and quartz fiber filter, respectively. Absolute recoveries were

determined by spiking 30 µL of 10 ng/µL of each target analyte before the extraction step

(to assess losses over the entire method, n=3) and before the concentration step (to assess

loss during the use of the TurboVap, n=2 only). This approach made it possible to 24 determine the extent which extraction or concentration contributed to the analyte loss. In both sets of experiments, the internal standard, PDFO (7:1 FtOH), was spiked into the

GC vial just prior to injection.

Instrumentation and Analysis. Selected ion monitoring (SIM) using GC/MS, in both positive chemical ionization (PCI) and negative chemical ionization (NCI) modes, was used for the analysis of the fluorochemicals. The primary mode for quantification was

PCI using a JEOL GC-Mate II magnetic sector mass spectrometer. PCI yields a unique

[M+1] ion for each analyte. NCI analysis, using an Agilent 6890 GC/Agilent 5973N MS detector, provided further confirmation of target analytes. In both PCI and NCI modes, analytes were confirmed by the presence of two masses, and the ratio of the two masses from a sample had to be within 10% of the ratio of a standard of similar concentration.

Due to low concentrations of analytes in some air samples, PCI did not always generate the second ion needed for ratio comparison. Moreover, PCI generates one ion only for

N-EtFOSA, 528 m/z. In these cases, NCI provided two ions of sufficient abundance for ratio comparison. Tables 2.5 lists the retention times and ions monitored for each analyte, in each chemical ionization mode.

Methane was the chemical ionization gas for both PCI and NCI modes, and helium was the GC carrier gas (0.9 ml/min flow rate). PDFO served as the internal standard for all analyses and was spiked into all sample vials just prior to GC injection except for the MBO 2006 samples, in which case it was spiked prior to extraction. This was done because the HSO and MBO 2004 samples were extracted prior to the start of this research, while MBO 2006 samples were extracted after the start of this research. 25

Thus, 2004 HSO and MBO concentrations were not recovery-corrected whereas MBO

2006 concentrations were recovery-corrected. GC inlet parameters were: 1 µL sample injection; pulsed-splitless injection, 25 psi until 0.50 minutes; purge flow of 20 mL/min at 0.40 minutes and gas saver turned on at 2.00 minutes. Chromatographic separation for non-olefin compounds was performed on an EC-Wax column (Alltech, 30m x 0.25mm x

0.25µm). Figures 2.2A shows a 50-picogram fluorochemical standard analyzed on an

EC-Wax column in PCI mode. The GC temperature program for the EC-Wax GC column was 400C for 1 minute, 30C/min until 1800C, then 200C/min to 2600C, 3 minute hold. The fluorinated olefins were separated on a less polar DB-5MS Column (J&W

Scientific, 30m x 0.25mm x 0.25µm). Figure 2.2B shows a 20-picogram fluorinated olefin standard analyzed on a DB-5MS GC column. The GC temperature program for the DB-5 GC column was 400C for 1 minute, 30C/min until 700C, then 250C/min until

3000C.

Figures 2.2C and 2.2D show sample chromatograms of fluorinated olefins measured in HSO on May 1, 2004 and FtOHs measured in MBO on May 10, 2004, respectively.

Instrumental Detection Limit. A National Institute for Occupational Safety and Health

(NIOSH) procedure 51 was used to determine the instrumental limit of detection (LOD)

and instrumental limit of quantitation (LOQ) for each target analyte. Five or more low-

level calibration standards, from 0.25 pg to 20 pg of analyte in 1 µL of ethyl acetate, were

analyzed and the standard error of the linear regression was calculated from equation 1: 26

1/2 2 ⎡ ⎛ ⎞ ⎤ ⎢ ∑⎜ Y − Y ⎟ ⎥ ⎝ pred obs⎠ Sy = ⎢ ⎥ (1) ⎢ N − 2 ⎥ ⎢ ⎥ ⎣ ⎦ where Ypred is the predicted response, Yobs is the observed response, and N is the number of calibration points plotted. LOD is equal to 3Sy/m, where m is the slope of the linear regression, and LOQ is equal to 3.33*LOD. 1/X weighting, where X is the actual concentration of a calibration standard, was used to ensure uniform variance over the entire range of calibration. Table 2.6 shows instrumental LODs for each combination of

GC column, mass spectrometer, and ionization mode used during GC/MS analysis . The

LODs from the NIOSH method for N-MeFBSE and N-MeFBSA were higher than the concentrations that produced a signal-to-noise ratio (S/N) greater than 3:1 in the chromatograms of these compounds; therefore in these cases, the 3:1 S/N ratio from the chromatogram was used as the LOD value. The LODs for 8:2 Ftene and 10:2 Ftene in

NCI mode (used for confirmation of analyte identity) were not estimated because these compounds were not frequently detected in the samples; however, the NCI sensitivities for these two compounds was similar to that for 12:2 Ftene (LOD of approximately 0.5 pg/µL). All air concentrations assigned as less than limit of quantitation or not-detected in this work indicate the instrumental limits of quantitation and detection respectively.

Data Quality Assurance. Nearly one-third of the measurements made by GC/MS were performed on calibration curve standards, solvent blanks, and check standards.

Calibration curves that consisted of at least 5 calibration points in the range 0.5 pg/µL to

50 pg/µL were generated with 1/X weighting. For a given compound, calibration curves 27 with R2 values less than 0.99 were rejected and rerun. Samples were reanalyzed if the concentration deviated more than 30 percent in a GC/MS check standard.

The sampling campaigns at HSO and MBO included lab blanks, travel blanks, and field blanks. Each type of blank consisted of a filter, PUF, and XAD portion. Field blanks were conducted on days when high-volume air sampling was not performed. With only one exception, none of the analytes could be detected in the lab and travel blanks from either the HSO or MBO campaigns; in one of the MBO 2004 travel blanks 8:2

FtOH was detected at less than the LOQ(instrumental limit of detection) in the XAD and filter fractions.

The HSO and MBO 2004 sampling campaigns had three and two field blanks, respectively. For HSO, one of the field blanks contained 6:2 FtOH and 8:2 FtOH at less than the LOQ in the XAD fraction. In one of the MBO 2004 field blanks, the XAD fraction had measurable concentrations of 6:2 FtOH, 8:2 FtOH, and 10:2 FtOH (less than

2 pg/m3) and measurable concentrations of 8:2 FtOH, 10:2 FtOH, MeFOSE, and EtFOSE in the QFF fraction (less than 3 pg/m3). This anomaly likely occurred because this MBO field blank passively collected air in the sampler for a week, instead of a day, before being removed from the air sampler (due to bad weather). On the other hand, at HSO, all field blanks and samples were removed from the sampler after 24 hours.

Four field blanks were collected throughout the MBO 2006 campaign and were removed from the sampler after 24 hours. For these four field blanks, 8:2 FtOH was detected from below the LOQ to ~3 pg/m3; 10:2 FtOH was detected from below the LOQ to ~2 pg/m3; N-MeFOSE was detected at the LOQ in one field blank and N-EtFOSA was 28 detected at ~1 pg/m3 in one field blank. No other analytes listed in Table 2.1 were detected in any of the field blanks from HSO and MBO (2004 and 2006). Finally, field blank concentrations were not subtracted from the measured sample concentrations.

In approximately 30% of the samples randomly-selected from MBO and HSO, back PUFs, used to determine analyte breakthrough during air sampling, and back QFFs, used to determine the sorption of gas-phase analytes on the filter, were analyzed; no analytes were detected in these samples. Thus, air samples collected at HSO and MBO are not likely to overestimate the amount of analyte in the particulate phase or underestimate concentrations in the gas phase because of sorption to the filter or breakthrough.

Since the archived samples were not originally intended for fluorochemical analysis, use of PTFE-containing labware had not been avoided. Fortunately lab blanks that had been processed at the same time as the samples, had non-detects for all analytes.

Moreover, the Tisch high volume air sampler had no PTFE-containing components.

Air Mass Back Trajectories. The source regions of sampled air masses were determined using NOAA’s HYbrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) 4.0 model46. For HSO, 4-day back trajectories of an air mass were calculated using

HYSPLIT and transposed into spatial representations using ArcGIS. Seven trajectories were calculated for every 24-hour sample at 250 meters above sea level (masl). Source region impact factors (SRIFs) were also calculated for each 24-hour sample. SRIFs describe the percentage of time that an air parcel trajectory spends in a particular source region 4 days before arriving at the sampling location and a detailed explanation has been 29 reported elsewhere45. Source region impact factors (SRIFs) for the samples collected during the HSO Spring 2004 sampling campaign are summarized in Table 2.245. Sources regions for the Okinawa data included China, Japan, the Koreas, Russia, and Ocean

(which includes the island of Okinawa).

For MBO, Nine (hourly) 10-day back trajectories were calculated for each sample date at 1300, 1500, and 1700 magl (meters above ground level) using HYSPLIT. SRIFs were calculated by creating boxes around Asia, Siberia, Alaska, Canada, Oregon,

Washington, California, and the Pacific Ocean (Figure 2.1). A SRIF, for MBO air trajectories, is defined as the percentage of time a trajectory (all trajectories less than 3 km) resided inside a box. Tables 2.3 and 2.4 depict SRIFs from 10-day back trajectories for the MBO Spring 2004 and MBO Spring 2006 campaign, respectively. Figures 2.3 and 2.4 show 10-day back-trajectories for the MBO Spring 2004 and MBO Spring 2006 campaign, respectively, in the form of density plots. A density plot of a trajectory depicts the number of hourly points that fell into the 10 by 10 coordinate grid. Darker parts of a trajectory indicate that more hourly points were from that location along the 10-day back trajectory.

Atmospheric Lifetime. Measured concentrations of FtOHs were used to calculate the atmospheric residence times using the Junge method47. The method uses the concentration variability in tropospheric trace gases (such as water and carbon dioxide) to estimate atmospheric residence time and has been used previously for SOCs such as polychlorinated biphenyls (PCBs)52-55. Junge discovered that residence time is inversely related to the spatial standard deviation of trace gas concentrations around the globe. 30

Trace gases with high variability have short residence times according to the equation,

T*σ = 0.14, where T is the atmospheric residence time in years and σ is the relative standard deviation of measured concentrations. The Junge calculation assumes that the environmental sinks of the analyte of interest are uniformly distributed in the troposphere and the analyte does not exhibit partitioning into environmental compartments (such as water) or participate in heterogeneous reactions47. A second assumption is that measurements are carried out year-long and around the globe at remote locations to measure the global background level of the analyte47. A third assumption is that the variability of the analyte in the environment is greater than the variability of the analytical method47.

Results & Discussion

Fluorochemical Recoveries. Fluorochemical average recoveries over the entire analytical method (Table 2.7) ranged from 0% (8:2 Ftene) to 74% (MeFOSE). Average recoveries for the concentration step only are depicted in Table 2.8 and ranged from 6.1%

(4:2 FtOH) to 53% (MeFBSE). There was no statistical difference at the 95% confidence level in analyte recoveries between the entire analytical method and the concentration step only. This indicates that the majority of analyte loss occurs during the concentration.

Higher FtOH and fluorinated sulfonamide recoveries are reported in the literature for analytical methods specifically designed to optimize the recovery of these compounds25, 56. In this study, previously extracted and concentrated archived samples were later analyzed for FtOHs, fluorotelomer olefins, and fluorinated sulfonamides.

Consequently, no control could be exercised in this study over the resulting recoveries of 31 the fluorochemicals in these archived extracts. However, previous studies, designed to specifically sample, extract, and concentrate FtOHs and fluorinated sulfonamides, used methods similar to those in this work (high-volume air sampling with PUF-XAD-PUF, solvent extraction, and solvent evaporation)3, 24-28, 56. Moreover, these archived extracts give us the opportunity to investigate correlations between fluorinated organic compounds and SOCs.

Relative standard error on single air measurement. Entire-method recoveries were used to estimate the relative standard error (RSE) of an air concentration measurement during one sampling event. Ignoring the systematic error associated with the method recoveries

(less than 100% recovery) for an analyte, the triplicate recovery of an analyte gave three measurements to assess the random error comprising the extraction, concentration, and

GC/MS analysis steps. If the triplicate method recoveries were 70%, 80%, and 90%, the average recovery ( X ) was 80% and the standard error (SE) was 5.7%. The relative standard error (RSE), % is given by equation 3.

SE RSE = *100 (3) X

Table 2.9 lists the analyte RSEs for the GFF, PUF, and XAD. For compounds detected in this study, the RSE ranged from 0.39 (8:2 FtOH in XAD) to 23% (EtFOSE in PUF).

Moreover, this entire-method RSE for a specific analyte may be used to compare population means if concentrations are also recovery-corrected. GC instrumental RSEs were also measured on the JEOL GC-Mate II instrument by the triplicate injection of a 10 pg/µL standard (Table 2.10). For compounds detected in this study, the RSEs ranged from 2.4 (6:2 FtOH) to 6.9% (MeFOSE and EtFOSE) in a 10 pg/µL standard. 32

Fluorinated organic compound concentrations. Tables 2.11, 2.12, and 2.13 give air concentrations (pg/m3) of fluorinated organic compounds measured in the spring 2004

HSO and MBO sampling campaigns and the spring 2006 MBO sampling campaigns, respectively. The gas-phase and particle-phase concentrations are shown in separate columns. The frequency of detection (FOD, %) of a specific analyte is shown in the bottom row of each table. Table 2.14 summarizes the average concentration, ranges, and

FODs of fluorinated organic compounds measured during the HSO and MBO 2004, and

MBO 2006 sampling campaigns. Table 2.15 summarizes air concentrations for fluorinated organic compounds reported in the literature. Figures 2.5, 2.6, and 2.7 show the concentrations (Σgas and particle) of fluorochemical analytes measured during the

HSO 2004, MBO 2004, and MBO 2006 sampling campaigns, respectively.

HSO 2004. Fluorotelomer olefins (Ftenes) were only measured at HSO. 10:2 and 12:2 fluorotelomer olefins were measured in the gas phase at concentrations as high as 1.6 and

2.2 pg/m3 with FODs of 61% and 22%, respectively. However, only two HSO air samples contained Ftene concentrations above the LOQ (see Figure 2.5C). The SRIFs for these two sample dates (April 1, 2004 and April 4, 2004) indicated large source region contributions (greater than 40%) from China (see Table 2.1).

10:2 Ftene and 12:2 Ftene were measured at low concentrations in the HSO air samples. Their presence in air is explained because of their high vapor pressures and

HSO’s proximity to possible direct and indirect sources in Japan, and possibly China.

There are two possible sources of fluorotelomer olefins in Japan- ammonium perfluorononanoate (APFN) or Telomer A synthesis. Japan has two locations that 33 produce Telomer A, a raw material for fluorotelomer-based products2. Telomer A synthesis creates fluorotelomer olefins as byproducts2. APFN, used in the synthesis of fluoropolymers, is made in Japan by telomerization of fluorotelomer olefins2. 8:2 Ftene is the primary olefin used in this process, but only 10:2 Ftene and 12:2 Ftene were detected in the air samples. 8:2 Ftene, which almost coelutes with ethyl acetate on the

30-meter DB-5MS GC column, is too volatile to be recovered in our method (Table 2.7).

In order to further assess the magnitude and significance of fluorotelomer olefins in the environment, methods must be developed to increase the recoveries of the fluorotelomer olefins.

Gas phase total fluorotelomer alcohol concentrations (Σ(6:2 FtOH, 8:2 FtOH, and

10:2 FtOH)) ranged from non-detect (

FtOH, and 10:2 FtOH were detected at around same frequency, and 10:2 FtOH was measured in highest average concentration level (Figure 2.5A). Finally, there were no significant correlations between FtOHs and Ftenes at HSO.

MeFOSE concentrations ranged from

MeFOSE consistently had the highest concentration and the highest FOD. There were no significant correlations between the sum of precipitation (Table 2.2, ∑ppt) along a trajectory and FOS concentrations. 34

Samples with SRIFs from the ocean (greater than 75%) had the highest measured concentrations of N-MeFOSE and N-EtFOSE, which were measured in both the particle and gas phases. The highest reported concentration of fluorinated organic compounds in

HSO occurred on March 21 and 24 where FOS analytes (particle and gas phase) were 48 and 26 pg/m3, respectively (Figure 2.5B). No statistically significant association of olefins, N-MeFOSE, and N-EtFOSE with source regions could be identified. Finally, fluorotelomer acrylates, perfluorooctane sulfonamido acrylates, N-MeFBSA, and N-

MeFBSE were not detected at HSO.

MBO 2004. Fluorotelomer olefins were not detected in 2004 and 2006 at MBO.

However, 6:2, 8:2, and 10:2 fluorotelomer alcohols (particle and gas phase) were measured from LOQ) in every MBO 2004 sample. On

May 21, FtOHs (∑particle and gas phase) were detected at their highest concentrations

(8:2 FtOH at 19 pg/m3, 10:2 FtOH at 8.8 pg/m3, and 6:2 FtOH at 4.0 pg/m3) (Figure

2.6A). The concentrations of 8:2 FtOH (particle and gas phase) were significantly correlated with those of 10:2 FtOH (p-value = 0.04). Moreover, FtOH concentrations

(particle and gas phase) were significantly greater at MBO in 2004 than at HSO in 2004 by an average of 8.9 pg/m3 (p-value = 0.048) in samples where FtOHs were measured. 35

MeFOSE and EtFOSE were found in both particle and gas phases. The concentrations of MeFOSE ranged from

MBO 2004 and HSO 2004

At MBO in 2004, FtOHs were detected more frequently than FOS analytes (p- value = 0.002). However, in samples where both were measured, there was no significant difference between FtOH and FOS concentrations (particle and gas phase). Also, Asia does not appear be a significant source of semi-volatile fluorochemicals to MBO because on April 25, a previously identified trans-Pacific air mass49, does not have elevated concentrations of FtOHs or FOSs relative to the other MBO 2004 samples. Finally, fluorotelomer acrylates, perfluorooctane sulfonamido acrylates, N-MeFBSA, and N-

MeFBSE were not detected at MBO in 2004.

MBO 2006. The MBO 2006 air concentrations were recovery-corrected by spiking with

PDFO prior to the extraction step. Since this was a more comprehensive data set (n =

34), FtOH source regions, signature ratios, and correlations with SOCs were examined.

Atmospheric residence times of FtOHs were also determined.

Figure 2.7 shows that 6:2, 8:2, and 10:2 fluorotelomer alcohols (particle and gas phase) concentrations ranged from 7.4 to 110 pg/m3. The concentrations of 6:2 FtOH ranged from

LOQ in every MBO 2006.

The concentrations of N-EtFOSA ranged from

For the first time, 8:2 FtAc was measured; its concentrations ranged from

4.3 pg/m3 in the particle phase and

8:2 FtAc in MBO 2006 may be due to the doubling of global fluorotelomer alcohol production in the period from 2000-200257. 8:2 FtAc concentrations were significantly correlated with 8:2 FtOH concentrations at MBO 2006 (p-value = 0.01). The latter correlation could be connected to the fact that 8:2 FtOH is a precursor used to make 8:2

FtAc2.

In the MBO 2006 samples, FtOHs were detected more frequently than FOS analytes (p-value = 0.0068). FtOH (particle and gas phase) concentrations were also greater by an average value of 41 pg/m3 than FOS concentrations in those days in which both analytes were quantified (p-value < 0.001); FtOHs were the predominant semi- volatile fluorochemicals of concern at MBO 2006.

Comparison of MBO 2006 to previous studies. Table 2.15 shows the average air concentrations of fluorinated compounds reported in the literature and figure 2.12 shows 37 a comparison of the average FtOH air concentrations at MBO 2006 versus reported average FtOH concentrations from literature. Compared to the average concentrations observed at MBO in 2006, Stock et al. measured 6:2 FtOH and 8:2 FtOH at higher concentrations in North America3. However, 10:2 FtOH was measured

Long Point and Toronto, Canada24. At the same time, Martin et al. 6:2 FtOH, 8:2 FtOH, and10:2 FtOH were measured in rural Long Point at average concentrations comparable to the concentrations measured in this study at MBO24. In Ottawa, Shoeib et al. measured

N-MeFOSE and N-EtFOSE at concentrations 2 to 20 times higher than the concentrations measured in this study at MBO 200626, 27. In 2006, Shoeib et al. measured average FtOH concentrations in the North Atlantic/Canadian Archipelago at approximately half the concentrations measured in this study at MBO25. 8:2 FtOH was the dominant FtOH in both the Shoeib 2006 study and MBO 2006 study. N-MeFOSE and N-EtFOSE were measured at similar concentrations as in MBO, yet these two compound were more frequently detected in the Canadian Archipelago25. N-EtFOSA was not detected in the

Canadian Archipelago study, while N-EtFOSA was detected in 65% of the samples at

MBO25. In a rural site in Germany, Jahnke et al reported average 6:2 FtOH and 8:2 FtOH concentrations approximately 10 times and 3 times higher than in this study at MBO, 38 respectively28. 10:2 FtOH was the FtOH of lowest concentration (versus 6:2 FtOH in this study at MBO 2006) and N-EtFOSE was the FOS of highest concentration (versus N-

MeFOSE in this study at MBO 2006)in this rural site28.

In general, FtOH concentrations measured in this MBO 2006 study were similar to those concentrations measured in the Arctic study by Shoeib et. al. and Long Point study by Martin et al., but lower than reported concentration in urban sites in Canada,

United States, and Germany.

Correlations between fluorochemicals at MBO 2006. Correlations among chemicals can possibly suggest similar source regions, similar indirect sources (e.g. residuals from consumer products), and/or similar behavior in the environment.

Statistically significant correlations (p-value < 0.05) measured at MBO in 2006 among the various organic fluorinated compound concentrations (particle and gas phase) are depicted in Table 2.16. In terms of concentrations, FtOHs were significantly correlated with each other. The concentrations of 8:2 FtOH were not significantly correlated with

N-MeFOSE and N-EtFOSE, while the concentrations of both 6:2 FtOH and 10:2 FtOH were significantly correlated to those of N-MeFOSE and N-EtFOSA. N-EtFOSA concentration was significantly correlated with N-MeFOSE. Finally, ∑FOS concentrations were significantly correlated with ∑FtOH concentrations.

Due to significant correlations between FtOH concentrations, the ratio of 6:2

FtOH to 8:2 FtOH to 10:2 FtOH (on a concentration basis, relative to the FtOH of lowest concentration) in the MBO 2006 samples was calculated to investigate how the ratio varies with source region and consumer product. The ratios were corrected using the 39 entire-method recoveries shown in Table 2.6 for each FtOH. Since the majority of MBO

2006 samples had similar ratios of 6:2 FtOH to 8:2 FtOH to 10:2 FtOH, an average ratio was also calculated. The average ratio of 6:2 FtOH to 8:2 FtOH to 10:2 FtOH in 30

MBO 2006 samples where all three were present was 1.0 (0.1) to 5.0 (0.7) to 2.5 (0.4), where the parenthesis represent the 95% confidence intervals for each FtOH, respectively. Neglecting environmental processes that might enrich one FtOH over the others, the average ratio of FtOHs in MBO is similar to the Teflon® Advance product in

Table 2.17 (the ratio of 6:2 FtOH to 8:2 FtOH to 10:2 FtOH was 1.0 to 3.5 to 1.9 in

Teflon® Advance)1. Principal component analysis, PCA, was used to investigate possible ratio groupings between consumer products and the average ratios of FtOHs (listed in

Table 2.17) from MBO 2006 and literature (Figure 2.9: PCA biplot). In Figure 2.9, the first two components in the biplot account for 98.7% of the variation in the multivariate data set. Possible distinct groups, based on average FtOH ratios, are shown in figure 2.9: squares (representing consumer products); triangles (representing different sampling locations); circles (representing groupings of consumer products and sampling locations).

One circle, in Figure 2.9, contains the MBO 2006 and the Arctic study (two remote sites influenced by the ocean), and the Teflon® Advance consumer product. The other circle contains the Hamburg/Waldhoff German study and the Zonyl FSO product. The biplot shows that ratios of FtOH concentrations may possibly be used to distinguish FtOH air masses coming from the remote sites and urban cities (e.g. MBO and Toronto) or urban sites in North America and Europe (Toronto and Germany studies). Moreover, there may be possible relationships between residuals from fluorotelomer-based consumer products 40 and concentrations of FtOH in remote sites (e.g. Teflon® Advance and MBO 2006 studies).

Source Regions of FtOHs. Air concentrations (gas phase and particulate) of 6:2

FtOH, 8:2 FtOH, 10:2 FtOH, 8:2 FtAc, ∑FtOHs, and ∑FOSs were not statistically correlated with site temperature (1/T) and wind speed in the MBO 2006 study. Jahnke et al found significant correlations between site temperature and ∑FtOH, FOSE, and

∑FOSA concentrations, but not with any other meteorological data28. A plot (Figure 2.8) of the log of individual FtOH concentrations (log [FtOH], pg/m3) versus reciprocal temperature showed no significant linear relationship between the log [6:2 FtOH], log

[8:2 FtOH], and log [10:2 FtOH] and 1/T (p-value for the each FtOH slope > 0.56). There was also no significant correlation relationship between Log [8:2 FtAc] and 1/T (p-value

> 0.50, data not shown). The shallowness of the slopes, or little site temperature dependence on log [FtOH] values, for the FtOHs in Figure 2.8, suggests that long-range transport (e.g. from regional sources in North America or the eastern Pacific Ocean) controls the concentrations of FtOHs at MBO because site temperature dependence is not related to the evaporation of analytes near the vicinity of the sampling site58. Moreover, the lack of site temperature dependence might suggest air masses containing background concentration of analytes (e.g. ocean)58.

With the lack temperature dependence on FtOH concentrations at MBO 2006, we also investigated SRIFs (Figure 2.1). The concentration of 8:2 FtOH (the most abundant

FtOH in MBO) was not significantly correlated with SRIFs from Alaska, Asia, Siberia,

Oregon, Washington, Canada, and California. However, the concentration of 8:2 FtOH 41 was significantly correlated (R= 0.37) with SRIFs from the Pacific Ocean 1 box (PO1 in

Figure 2.1) using trajectories at less than 1km and trajectories at less than 3km in altitude to compute SRIFs. We are still investigating this FtOH-Pacific Ocean relationship.

Initial investigation of urban centers SRIFs (boxes not shown) showed significant correlations between FtOHs and high population density urban areas like Portland (OR),

Seattle (WA), the San Francisco Bay Area (CA), and Southern California. This urban

SRIF relationship with FtOHs is currently being investigated.

Gas-Particle partitioning. Gas-particle partitioning, related to temperature and vapor pressure, is an important factor in the fate and transport of organic compounds in the atmosphere. Figure 2.10 shows the average percentage of fluorinated compound measured in the gas phase at HSO and MBO 2004, and MBO 2006. The error bars show

95% confidence intervals (95% CI).

At HSO, the average sampling temperature was 19.5 0C; 6:2, 8:2, and 8:2FtOH were measured solely in the gas phase. Also 10:2 Ftene and 12:2 Ftene (data not shown in Figure 2.10) were found solely in the gas phase, except 10:2 Ftene was measured at

MeFOSE and N-EtFOSE were both 14% (+/-27%, 95% CI)) in the gas phase.

For the MBO 2004 samples, the average sampling temperature was -2.1 0C; 6:2

FtOH, 8:2 FtOH and 10:2 FtOH were measured at 67% (+/-65%), 75% (+/-9%), and 57%

(+/-7%) in the gas phase, respectively. By comparing their mean gas phase percentages,

8:2 FtOH was measured to be 20% more in the gas phase than 10:2 FtOH. N-EtFOSA 42

(data not shown in Figure 2.10) was found at

May 10 (temperature = -5.5 0C) and 32% in the gas phase on July 7 (temperature data was not available).

For the MBO 2006 samples, where the average sampling temperature was -0.8 0C,

6:2 FtOH, 8:2 FtOH and 10:2 FtOH were measured to be 98% (+/-2%), 54% (+/-9%), and 36% (+/-11%) in the gas phase, respectively, and 8:2 FtAc was measured to be 47%

(+/-20%). Both MBO 2004 and 2006 gas phase partitioning data show that, unlike HSO,

8:2 FtOH and 10:2 FtOH may undergo significant gas to particle partitioning in cooler regions. By comparing their mean gas phase percentages, 6:2 FtOH was measured to be

44% more in the gas phase than 8:2 FtOH and 8:2 FtOH was measured to be 18% more in the gas phase than 10:2 FtOH. Moreover, there was no significant difference in gas- particle partitioning between 8:2 FtOH and 8:2 FtAc. This suggests that the vapor pressure of 8:2 FtAc may be similar to 8:2 FtOH. N-EtFOSA (data not shown in Figure

2.10) was measured to be 27% (+/-11%) and N-MeFOSE was measured to be 57% (+/-

31%) in the gas phase. N-EtFOSE was found in only two samples: 100% in the particle phase on April 29 (temperature = 0.40C) and

(temperature = 8.40C).

A plot (Figure 2.11) of the fraction of FtOH in particle phase, Φ versus 1/T for

6:2 FtOH, 8:2 FtOH, and 10:2 FtOH showed no correlation. This implies that other factors, not site temperature, control gas-particle partitioning at MBO during the 43 springtime. Shoeib et al. also found no significant correlations between particle-phase to gas-phase ratio versus 1/T for FtOHs in the Canadian Arctic (6:2 to 10:2 FtOH)25, while

Janhke et al. found a significant correlation in a study of urban and rural air in

Germany28.

In previous studies of fluorinated compounds in air, Jahnke et al. measured FtOHs

(4:2 -10:2 FtOH) in the gas phase only where ambient temperatures ranged from 5 to

200C; FOSEs were measured mainly in the particle phase at 9.20C and greater than 85% in the gas phase at 16.80C28. Shoeib et al. measured 6:2 FtOH at 100%, 8:2 FtOH at

77%, 10:2 FtOH at 85%, N-MeFOSE at 68%, and N-EtFOSE at78% in the gas phase in samples collected from the Canadian Archipelago and North Atlantic Ocean where the average temperature was 50C25.

Correlations between FtOH concentrations and SOC concentrations. Wania, discussing the Arctic enrichment of organic chemicals, characterized chemicals with Log Kaw

59 values between -1 and -2 and log KOA between 3 and 9 as “multiple hoppers .” These chemicals exchange reversibly with marine and continental surfaces and undergo long-

59 range atmospheric transport to remote locations . The measured log KOA values of

FtOHs range from 3.3 to 4.8, and their log KAW values from -1.52 to -0.53 (from Table

1.2); therefore FtOHs fit Wania’s definition of “multiple hoppers.” Other examples of

SOCs that are “multiple hoppers” include hexachlorobenzene (HCB) and PCBs59.

The correlations between FtOH concentration and SOC concentration could be determined in the present study since MBO 2006 samples were also analyzed for SOCs.

Details of the analytical method for SOC analysis are found elsewhere44, 45. Table 2.18 44 lists all the significant correlations between FtOHs and SOCs. The concentration of 6:2

FtOH was positively correlated (p-value < 0.05) with trans-chlordane (TC), trans- nonachlor (TN), PCB-118, PCB 138, PCB 153, fluorene, phenanthrene, anthracene, fluoranthene, and pyrene. The concentration of 8:2 FtOH was positively correlated (p- value < 0.05) with concentrations of HCB, metribuzin, trans-chlordane, fluorene, and phenanthrene. While 8:2 FtOH concentrations were negatively correlated (p-value

<0.05) with concentrations of dacthal, endosulfan I, endosulfan II, and endosulfan sulfate.

The concentration of 10:2 FtOH was positively correlated (p-value < 0.05) with concentrations of metribuzin, trans-chlordane, PCB-118, PCB-138, PCB-153, fluorene, phenanthrene, anthracene, fluoranthene, and pyrene whereas10:2 FtOH concentration was negatively correlated with concentrations of endosulfan I (p-value <0.05). Finally, we found no significant correlations between α-HCH and FtOH concentrations.

In general, FtOH concentrations were positively correlated (p-value <0.05) with gas phase PAHs such as phenathracene and anathracene, but were not significantly correlated with particle phase SOCs such as benzo(k)fluoranthene and benzo(e)pyrene.

Further, FtOH concentrations were negatively correlated (p-value <0.05) with agricultural pesticides such as dacthal and endosulfan. This suggests that FtOHs in the

Pacific Northwest are coming from urban sources, not agricultural sources regions.

FtOHs were also significantly correlated with HCB and PCBs as predicted by the

“multiple hopper” definition developed by Wania59.

Atmospheric Residence Times of FtOHs. Using the Junge method of trace gas variability, the estimated atmospheric residence times of 6:2 FtOH, 8:2 FtOH, and 10:2 FtOH were 45

50, 80, and 70 days, respectively. These long residence times suggest that FtOHs have the potential to undergo long-range transport.

Applying the Junge equation to air samples collected in Bermuda (a remote site),

Panshin determined the residence times of individual PCB congeners to be between 40-

75 days54; using the same method, Manchester-Neesvig determined an average atmospheric residence time of 60 days for PCB congeners55, Biddleman previously reported residence times of 45-67 days for PCB-54 congeners53, and Atlas reported atmospheric residence times of 60-180 days for PCB-42 congeners52 . More recently,

Anderson reported PCB residence times due to OH radical to be from 2 days (for biphenyl) to 34 (for pentachlorobiphenyl) days based on photochemical reactor studies60,

61. These studies indicate that atmospheric residence times can vary by a factor of 2 to 3 depending on the method used.

Most of the assumptions underlying the Junge equation were met. Though not measured year-round, samples were collected daily throughout the spring and 6:2, 8:2, and 10:2 FtOHs were above the quantification limit in almost every sample. Second, the environmental sinks of FtOHs are uniform, since OH radical, their likely main mechanism of atmospheric removal, is distributed evenly around the globe. Third,

FtOHs, with their high vapor pressures, are similar to trace gases. Moreover, the FtOH concentrations measured at MBO are likely representative of a global background with sample trajectories coming from the Pacific Ocean, Alaskan, and Artic regions. Finally, the variance associated with the analytical measurements of FtOHs was smaller (RSD

<10%) than their concentration variance in the atmosphere. 46

Conclusion. FtOH concentrations at MBO 2006 are correlated with SOCs such as PCBs and HCB, known to be “multiple hoppers” with relatively high potential to accumulate in the Arctic59. Semi-volatile fluorinated organic compounds, especially FtOHs, are persistent compounds (with atmospheric residence times greater than 50 days) capable of undergoing long-range transport to remote locations. Alongside MBO and HSO in this study, FtOHs have been measured in urban, rural, and remote areas in North America,

Europe, Asia, and the Canadian Arctic.

In this study, positive correlations of FtOHs with PAHs and PCBs at MBO in

2006 indicate that sources of FtOHs may be urban. From initial studies, positive correlations of FtOHS with SRIFs of urban areas around the west coast of the United

States also suggest that the sources of FtOHs are urban.

We also found significant correlations between FtOH and SRIFs of the Pacific

Ocean near the west coast of the United States. Thus, air samples and water samples collected at the ocean surface are needed to investigate the prevalence of semi-volatile organic compounds in the ocean.

With the average residence times greater than 50 days, comparing the ratios of 6:2

FtOH to 8:2 FtOH to 10:2 FtOH might be a viable method for understanding source regions and fluorinated residual products from consumer products. However, more consumer product and indoor air data is needed to understand the significance of fluorotelomer-based residual offgassing.

Future research should focus on sampling a wide-variety of environmental matrices, including snow, vegetation and fresh water ecosystems, especially in cold 47 locations where gas/particle partitioning allows for wet/dry deposition of 8:2 and 10:2

FtOH. Moreover, sensitive and efficient analytical methods are needed for the analysis of Ftenes, which might represent a large quantity of fluorochemical emitted in Asia. 48

Acknowledgements

The author expresses thanks to Dupont for an unrestricted gift, EPA STAR program, and the NSF for CAREER GRANT ATM-0239823. 49

Tables and Figures

Table 2.1: Fluorinated alkyl analyte, acronym, chemical structure, vendor, and purity information.

Purity Analyte Name Acronym Chemical Structure Vendor %