Document 1gOzd813X5JOQXXGb36n3aDea

PHOTODEGRADATION f7~~ 2- TEST SUBSTANCE Identity: Perfluorooctanesulfonate; may also be referred to as PFOS or FC-95. (1-Octanesulfonic add, 1,1,2,2,3,3,4,4,5,5,6,6,7,7,8,8,8heptadecafluoro-, potassium salt, CAS # 2795-39-3) Remarks: Testing is in progress. 000211 PHOTODEGRADATION TEST SUBSTANCE Identity: Perfluorooctanesulfonate; may also be referred to as PFOS or FC-95. (1-Octanesulfonic acid, 1,1,2,2,3,3,4,4,5,5,6,6,7,7,8,8,8heptadecafluoro-, potassium salt, CAS # 2795-39-3) Remarks field: The test substance is a white powder. The test substance used was 14C labeled (285 dpm/pg). Purity of the test substance is not described. This testing is currently being repeated using current procedures and best available practices. METHOD ___________________________________________________ Method/guideline followed: Procedure as described in the Federal Register (Volume 43, No. 132-Monday, July 10,1978) by the U.S. Environmental Protection Agency. Type (test type): Simulated sunlight GLP (Y/N): No Year: 1978 Light Source: General Electric F-40BL fluorescent black light Light Spectrum (nm): Max output at ~360 nm and essentially no output below 300 nm. Spectral energy characterized from 290-600 nm. Intensity: Wavelength 290 - 300 3 1 0 -3 2 0 320 - 340 340 - 360 3 6 0 -3 8 0 3 8 0 -4 0 0 4 0 0 -5 0 0 5 0 0 -6 0 0 Watts Radiated 0.090 0.235 1.410 1.910 2.310 1.680 2.300 0.340 Spectrum of substance (max lambda, max epsilon and epsilon 295): Not determined. Remarks field: - Test medium (air, water, soil, other - specify): Distilled water - Duration: 30 days - Positive Controls: None - Negative Controls: None 000212 Photolyzate samples were collected after irradiation intervals of 0, 3, 7 ,1 5 , and 30 days. Samples were analyzed using a Liquid Scintillation Counter (LSC), TLC-Autoradiograph and Gas Chromatography. RESULTS________________________________________________________ Concentration of Substance: 50 mg/L Temperature C: 23+3C Degradation %: 0% after 30 days Remarks field: No photodegradation of the test substance was detected in this study. Essentially the same analysis results were obtained for the 30-day photolyzate sample (no photoproducts formed) as the 0-day sample. Radiocarbon assays at 0 and 30 days also indicate no significant amount of product was volatilized during the study. CONCLUSIONS No photodegradation products were detected in this study using simulated sunlight, indicating the test substance does not undergo photolysis. Submitter: 3M Company, Environmental Laboratory, P.O. Box 33331, St. Paul, Minnesota, 55133 DATA QUALITY__________________________________________________ Reliability: Klimisch ranking 2. Photolysis study is being repeated using currently available procedures and best practices using a sample with characterized purity. REFERENCES___________________________________________________ 3M Technical Report "FC-95/PHOTOLYSIS STUDY USING SIMULATED SUNLIGHT." J. W. Todd, Project 9776750202, January 9,1 97 9 O T H E R _________________________________________________________ Last changed: 5/2/00 000213 SUMMARY OF PHOTOLYSIS STUDY USING SIMULATED SUNLIGHT ON THE POTASSIUM SALT OF PERFLUOROOCTANESULFONIC ACID Exposure Conditions This study was performed on the potassium salt of perfluorooctanesulfonic acid as described in Federal Register (Volume 43, No. 132-Monday, July 10,1978) by the U.S. Environmental Protection Agency. The test solution contained 50 ppm of ,4C labeled potassium perfluorooctanesulfonate (285 dpm/ug) in 2 liters o f D.I. water. The specific activity of the solution was 14,250 dpm/ml (0.0064 uC/ml). r The photoreactor contained a General Electric F-40BL fluorescent black light with a maximum output at about 360 nm and essentially no output below 300 nm. The temperature o f the reactor was controlled at 23 3 C by circulating tap water. Photolyzate samples were collected after irradiation intervals o f 0, 3, 7,15, and 30 days. Collected samples were removed through the reactor drain port and were refrigerated until analyzed. Analysis o f Photoproducts bv TLC-Autoradiography A 100 ml aliquot of the 0 and 30 day photolyzate samples were concentrated with a rotary vacuum evaporator and a water bath to dryness, redissolved in 3 ml of methanol, and transferred with two 3 ml washings into Kudema-Danish concentrator tubes. Each solution were further concentrated to 1 ml. A 10 ul aliquot of each sample (equivalent to 1 ml of the original photolyzate solution) was transferred onto a Thin Layer Chromatography (TLC) plate using a 10 ul syringe. Each plate was developed two-dimensionally with ethyl acetate/acetic acid (95/5) followed by ethyl acetate/chloroform/formic acid/water (65/20/10/5). After air drying, the spots were scraped and quantified for radioactive carbon. Analysis o f Photoproducts bv Gas Chromatography Photolyzate samples from days 0 and 30 were analyzed by acidifying 2.0 ml of each in a 4-dram vial with 0.2 ml o f concentrated HC1 and extracting with two 2 ml portions of diethyl ether. The combined extracts of each sample were concentrated to 0.1 ml in a 10-ml Kudema-Danish concentrator tube using a nitrogen purge. The concentrated samples were methylated with 0.4 ml o f diazomethane methylating solution and mixed well. Using a 10 ul syringe, 6 ul o f sample (equivalent to 1.5 ug of the compound o f interest) was injected, via on-column injection at 150 C, into a Model 7620 Hewlett-Packard gas chromatograph with a 6 ft X 1/8 in. O.D. stainless steel packed column with 5% OV-17 silicone on Chromosorb G support. The GC column oven was temperature programmed from 60 to 150 C at 15 C/min. Analytes were detected with a microwave sustained helium plasma detector from Applied Chromatography Systems Limited, Luton, England. The detector was operated in the fluorine and sulfur modes simultaneously with outputs to a dual-pen recorder. Results No photodegradation products were detected in this study. Similar radiocarbon assays (with good analyte recoveries) and similar gas chromatograms were obtained from the 0 and 30 day samples. 000214 JuJy22' 1998 TECHNICAL REPORT SUMMARY ro: TECHNICAL COMMUNICATIONS CENTER - 201-2CN Dit 1-9-79 Im p o rtan t - I f re p o rt h p rin te d on both sides o f paper, ten d tw o copies to T C C .i Division ?roject Report it* ro Commercial Chemicals Division - Agrichemicals Project Service to TOSCA FC-95/PHOTOLYSIS STUDY USING SIMULATED SUNLIGHT R. A. Prokop Dept.Number 3068 ProtectNumbar 9776750202 ReportNumbar 001 J. W. Todd Notebook Reference Agrichemical Request 888 A3953 incJudingovrm--t' 13 S E C U R IT Y ^ Opan (Com pany C o nfidential) Cloud (Spacial A u th o rizatio n ) 3M C H E M IC A L ^ R E G IS T R Y ^ N ew Chemicals R aportad O Ya* g No KEYW ORDS: (Salact tarm i fro m 3M Thesaurus. Suggest othar applicabla tarm s.) C U R R E N T O B JE C TIV E : Investigate the photolylic stability of FC-95 as a function of irradiation time and identify any major photo products. to/Radiography composition vironment s-Chromatography yer/Chromatography R E P O R T A B S TR A C T: (2 0 0 -2 5 0 words) This abstract info rm ation is distributad by tha Technical Com m unications Cantar to start 3M *art to Company R & D .. otolysis diotracer intillation Irradiation of a 50 ppm aqueous solution of FC-95 for 30 days resulted in no detected photoproducts on analysis by thin-layer-chromotography/radioautography, and by gas chromotagraphy of derivatized samples using a microwave plasma detector. The irradiation source produced 300 nm and longer wavelength light to simulate natural sunlight. Inform atio>nn ILJiaisioon LInitials: 000215 FC-95/PHOTOLYSIS STUDY USING SIMULATED SUNLIGHT INTRODUCTION It is generally acknowledged that manufactured chemicals may find their way into the environment in various degrees and by various means. Once in the environment they may be destroyed or chemically altered by the action of sunlight (Crosby and Li, 1969). This study investigated the possible photodegradation of FC-95 in distilled water on exposure to simulated sunlight (Kohler, 1965). This study was conducted essentially as recommended by the Environmental Protection Agency (Federal Register). EXPERIMENTAL 1. Sample Materials FC-95 is the potassum salt of perfluorooctanesulfonic acid. C8F 17S03K The major component is the straight-chain CQ but some branched chain isomers and other homologs also are present. FC-95 Water Solution. A 50 ppm solution of FC-95-1^C (285 dpm/jig) was prepared by dissolving 100.0 mg of FC-95 in 2 liters of distilled water. The resulting solution had a specific activity of 14,250 dpra/ml (0.0064 /iC/ml). 2. Analysis Inatruments/Materials Liquid Scintillation Counter (LSC) Nuclear-Chicago Mark I Rotary Evaporator Btlchi Rotovapor R Kuderna-Danish Concentrator 10 ml concentrator tube - Kontes No. K-570050 Reflux column - Kontes No. K-569251 Heated water bath 000216 * ; 4 'r .' -Vi';' ' -2- Thin-Layer Chromatography (TLC) plates MERCK Silica Gel 60 F-254, 0.25 mm thickness and 20 x 20 cm size 1st developing solvent - ethyl acetate/acetic acid 95/5 2nd developing solvent - ethyl acetate/chloroform/formic acid/water, 65/20/10/5 X-Ray Film KODAK NS-5T, 8 x 10 inch size Gas Chromatography System (GC) Gas chromatograph - Hewlett-Packard Model 7620 Column - 6 ft 1/8 in od stainless steel packed with 5% 0V-17 silicone on CHR0M0S0RB G support. Column temperature- 60 to 150 programmed at 15*C/min. Injector - on-column at 150C . Detector - microwave sustained helium plasma from Applied Chromatography Systems Limited, Luton, England DIAZALD D.IAZALD is Aldrich Chemical Company's trade name for N-methyl-N-nit roso-p-toluenesulfonamide. It is used to prepare diazomethane, an analytical reactant chemical. Diazomethane solution - Alcohol Free. Diazomethane (DAM) was used to convert acidified FC-95 into its corresponding methyl sulfonate ester just prior to gas chromato graphic analysis. CqF17S03H + CH2N2 -------- > CgF17S03CH3 + N2 T (FC-95 acid) (DAM) (FC-95 methyl ester) The DAM reagent used must be free of alcohols or the desired reaction product will n o t ;form or will degrade after it has formed. The alcohol-free DAM was prepared essentially as recommended by Aldrich: A solvent mixture consisting of 35 ml of 2-(2-ethozyethoxy)-ethanol and 20 ml of diethyl ether was added to a solution of 6 grams of potassium hydrozide dissolved in 10 ml of water. This mixture was 000217 placed in a 100 ml long-necked distilling flask fitted with a dropping funnel, an efficient condenser and a water bath at 70C. As the distillation of the ether started a solution of 21.5 g of DIAZALD in about 200 ml of ether was added through the dropping funnel over about 20 minutes. The etheral DAM solution was collected in a 250-ml Erlenmeyer flask cooled in an ice bath. The flask contents were transferred into a bottle, sealed with a TEFLON-lined cap and stored in a freezer. 3. Irradiation The preparative photoreactor used (Crosby and Tang, 1969) is illustrated in Figure 1. The lamp employed was a General Electric F-40BL fluorescent black light with maximum output at about 360 nm and essentially no output below 300 nm (Table I, Gnral Electric Co.). The temperature was controlled at 23 + 3C by circulating tap water through flexible plastic tubing wrapped around the reaction chamber. Nitrogen was passed through the photolysis solution at 20 ml/min to provide mixing. The exit port was connected to a vapor trap. The trap consisted of a 6 x 3/4 in. glass tube containing first XAD-2 resin and then charcoal. The photolyzate was sampled after irradiation intervals of 0, 3, 7, 15 and 30 days. The samples were removed through the reactor drain port and were refrigerated until analyzed. 4. Radiocarbon Recovery The photolyzate samples were assayed for radiocarbon by LSC to determine radiocarbon recovery as a function of irradiation time. Similar results were obtained for all samples. Results for the 30 and 0-day samples are presented in Tables II and III, respectively. 5. Investigation for Photoproducts by TLC-Autoradiography Aliquots of the 30 and 0-day photolyzates were reduced in volume 100-fold before TLC analysis. First a 100-ml aliquot of each sample was concentrated to about 5 ml using a rotary vacuum evaporator with a 40-50 C water bath, 50 ml of acetonitrile was added and the rotovac'ing continued to just dryness (Acetonitrile was added to expeditiously re move remaining water as an azeotrope and thereby minimize possible loss of radiocarbon). 000218 The samDle solids were dissolved in 3 ml of methanol and quantitatively transferred into a Kuderna-Danish concentrator tube with two additional 3-ml washings. Reflux tubes were attached and the concentrator tubes were immersed in a 65-74C water bath. The tube contents were con centrated to exactly 1 ml. A 10.0 il aliquot of each sample concentrate (equivalent to 1.0 ml of the original photolyzate solution) was transferred onto a TLC plate using a 1 0 /al microsyringe. Each plate was developed two-dimensionally, first with ethyl acetate/acetic acid (95/5) and then with ethyl acetate/chloroform/formic acid and water (65/20/10/5). The air-dried TLC plates were then radioautographed. Figures 2 and 3 are pictures of the 30 and 0-day radioautographs, respectively. Various component spots and areas on each TLC plate were quantitated for radiocarbon by carefully sdraping the silica gel from the plate and LSC counting. The results are presented in Tables II arid III. 6. Investigation for Photoproducts by Gas Chromatography Sulfonate salts as FC-95 are not analyzable by gas chromatography. Recent work has shown that FC-95 is analyzable if acidified, isolated from the water matrix and methylated with DAM. The 30 and 0-day photolyzate samples were analyzed by this method (3M Central Research Laboratory). The procedure used is summarized below: Two ml of the photolyzates were pipetted into 4-dram vials. Each sample was acidified with 0.2 ml of concentrated hydrochloric acid and the resulting acids were quantitatively extracted with two-2 ml portions of diethyl ether. The combined ether extracts were concentrated to 0.1 ml in a 10-ml Kuderna-Danish concentrator tube using a nitrogen, purge. The concentrated extracts were diluted to 0.4 ml with DAM solution and mixed well. Using a 10 /al microsyringe,6 jjI sample portions (equiva lent to 1.5 pg of FC-95) were injected into the gas chromatograph for analysis. The microwave plasma detector was operated simultaneously in the fluorine and sulfur modes with outputs to a dual-pen recorder. The chromatograms for the 0 and 30-day photolyzate samples are pre sented in Figure 4. 000219 -5 - This analysis method is unique in that 1) there are only a few micro wave plasma .detectors in this country and 2) methyl esters of sulfonic and fluorosulfonic acids generally have been considered to be too unstable for gas chromatographic analysis. The analysis results here demonstrate that FC-95 indeed can be analyzed by gas chromatography. Several less obvious paramaters also are important: The DAM solution should be freshly prepared, preferably the same day it is used. Excess DAM is necessary in the analyzed sample solution and its presence is evidenced by a characteristic yellow color. Several injections of sample may be necessary to passivate the column before accurate and repeatable results are obtained. Presence of diazomethane in the analyzed sample produces interfering peaks when the more conventional flame ionization and electron capture detectors are used but does not interfere with the microwave plasma detector used here. RESULTS No photodegradation of FC-95 was detected in this study. Essentially the shme analysis results were obtained for the 30-day photolyzate sample (no photoproducts formed) as the 0-day sample. Similar radiocarbon assays were obtained. (Tables II and III). Therefore no significant amount of radiocarbon was volatilized during the photolysis and so the contents of the vapor trap were not analyzed. Similar TL-C-radioautographs were obtained indicating no change in composition in the 30-day sample compared to the O-day sample (Figure 2 and 3). Quantitative measurement of radiocarbon in various TLC spots and background areas show similar radiocarbon distribution and good recoveries (Tables II and III). Similar gas chromatograms were obtained further confirming the same composition of the 30 and 0-day samples (Figure A). J. W. Todd 000220 -6 - REFERENCES Crosby, D.G. and Li, M. 1969. Herbicide Photodecomposition, Chapter 12:321-363 in Degradation of Herbicides, Kearney, P.C. and Kaufman, D.D. (ed), Marcel Dekker Inc. New York, 394 p. General Electric Company, Information from their Lamp Division, F40BL black light bulb. ! Koller, L.R. 1965. Ultraviolet Radiation, 2nd Ed. Wiley, New York. 312 p. Federal Register, Volume 43. No. 132-Monday,. July 10, 1978. Crosby,'D.G. and Tang, C.S., J. Agric. Food Chem., 17. 1041 (1969). 3M Central Research Laboratory, Analytical Request A-70732. 000221 Figure 1 - Photoreactor Got inlot fyrot glott onvolopo F-401L flooroocont bulb 000222 Table I - Spectral Energy Distribution for a GE F40BL Black Light Bulb Wavelength 290 tm 300 310 - 320 320 - 340 340 - 360 360 - 380 380 m 400 400 m 500 500 600 Watts Radiated 0.090 0.235 1.410 1 . 9 1 0 ^ Maxlmua intensity 2.3 1 0 V at about 360 nm 1.680 2.300 0.340 000223 Figure Photograph of TLC Radioautograph, 30-Day FC-95 Photolyzate 1S T COPyAVAILABLE DS-2 A DS-1 Reference Samples. 5 jig of FC-95)--1A'4C 14,250 DPM, pot photolyzed3; FC-95 Origin Background (All area less spots 1 and 2) DS-1 = Developing Solvent 01, ethyl acetate/acetic acid,95/5. DS-2 = Developing Solvent 02, ethyl acetate/chloroform/formic. acid/water,65/20/10/5. 000224 Figure 3 - Photograph of TLC Radioautograph, 0-Day.FC-95 Photolyzate BIST COPY AVAILABLE DS-2 -- :------ > A DS-2 Reference Samples. 50 xig of FC-95-l^C fl4,200 DPM, "N \not phototyzed/ FC-95 Origin Background (All area less spots 1 and 2) DS-1 = Developing Solvent #1, ethyl acetate/acetic acid95/5. DS-2 r Developing Solvent #2, ethyl acetate/chloroform/formic acid/water,65/20/10/5. 000225 Table II - Radiocarbon recovered in 30-Day Photolyzate Solution and TLC Plate Scrapings (FIGURE 2) Sample Solution DPM/ml Relative % Area TLC Plate Scrapings Description DPMiper ml) % Recovery 14,430 H 1 FC-95 2 Origin. 13,873 49 96 0.3 3 "Background" 1,276 9 ' Total 15,198 103 x* * The amount of 14C radioactivity on the plate is equivalent to 1 ml of the original photolyzate solution. Table III - Radiocarbon recovered in 0-Day Photoyzate Solution and TLC Plate Scrapings (FIGURE 3) Sample Solution TLC Plate Scrapings DPM/ml Relative % Area Description DPMtper ml) % Recovery 14,425 [i0g ... 1 FC-95 2 Origin. 3 "Background" Total 13,465 26 1,600 15,091 93 0.2 11 104 * The amount of 14C radioactivity on the plate is equivalent to 1 ml of the original photolyzate solution. 000226 Figure A - Microwave Plasma Gas Chromatogram of Derivati zed Photolyzate Samples. 0-Day Sample 30-Dav Sample . Fluorine (|XA> -f * Detector Response Peak Retention Time in Minutes 20 000227