Document wqgOwd3VpVRD78YY03D2zeRdQ

FC-95/PhotolysisStudy Using SimulatedSunlight.(Note: the 3M Env. Lab summary isti0ed:summary of PhotolysisStudy Using SimulatedSunlighton the Potassium Saltof Perfluorooctanesulfonaiccid) PHOTODEGRADATION TEST SUBSTANCE Identity:Perfluorooctanesulfonatmea;y alsobe referredtoas PFOS or FC-95. (1-Octanesulfonicacid,1,1,2,2,3,3,4,4,5,5,6,6,7,7,8,8,8heptadecafluoro-p,otassium saltC,AS # 2795-39-3) Remarks field:The testsubstance isa whitepowder. The test substance used was 14C labeled(285dpm/pg). Purifyof thetestsubstance isnotdescribed.Thistestingis currentlbyeing repeatedusing currentproceduresand bestavailablepractices. METHOD Method/guideline followed: Procedure as describedinthe Federal Register(Volume 43, No. 132-Monday, July10, 1978) by the U.S. EnvironmentalProtectionAgency. Type (testtype): Simulated sunlight GLP (Y/N): No Year: 1978 LightSource: GeneralElectriFc-40BL fluorescenbtlacklight LightSpectrum (nm): Max outputat-360 nm and essentiallnyo output below 300 nm. Spectralenergy charactedzedfrom 290-600 nm. Intensity: Wavelength 290-300 310-320 320-340 340-360 360-380 380-400 400-500 500-600 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):Distillewdater -Duration: 30 days -PositiveControls: None -Negative Controls: None Photolyzatesamples were collecteadfterirradiatiionntervalosf0, 3,7, 15, and 30 days. Samples were analyzedusinga LiquidScintillatCiounnter (LSC),TLC-Autoradlographand Gas Chromatography. RESULTS Concentrationof Substance: 50 mg/L Temperature OC:23+30C Degradation %: 0% after30 days Remarks field:No photodegradationofthetestsubstancewas detected inthisstudy.Essentialltyhesame analysisresultswere obtainedforthe 30-day photolyzatesample (no photopmductsformed)as.the0-day sample. Ii Radiocarbonassays at0 and 30 days alsoindicatneo significaanmtount of productwas volatilizdeudringthestudy. CONCLUSIONS No photodegradationproductswere detectedinthisstudyusingsimulated sunlighti,ndicatintghetestsubstancedoes notundergophotolysis..- Submifter: 3M Company, EnvironmentalLaboratoryP,.O.Box 33331, St.Paul,Minnesota,55133 DATA QUALITY ReliabilityK:limidchranking2. Photolysistudyisbeingrepeatedusing .currentalvyailablperoceduresand bestpracticesusinga sample with characterizedpurfty. REFERENCES 3M TechnicalReport"FC-95/PHOTOLYSIS STUDY USING SIMULATED SUNLIGHT.N J.W. Todd, Project9776750202, January9,1979 OTHER Lastchanged: 5/2/00 SUMMARY OF PHOTOLYSIS STUDY USING SIMULATED SUNLIGHT ON THE POTASSIUM SALT OF PERFLUOROOCTANESULFONIC ACID ExRosure Conditions This study was performed on the potassiumsaltof perfluorooctanesulfonaiccid as describedin FederalRegister(Volume 43, No. 132-Monday, July 10,1978)by the U.S. EnvironmentalProtection Agency. The testsolutioncontained50 ppm of "C labeledpotassium perfluorooctanesulfona(t2e85 dpm/ug) in2 literosf D.I.water.The specifiacctivitoyfthesolutiownas 14,250dpm/ml (0.0064uC/ml). The photoreactorcontaineda General ElectricF-40BL fluorescenbtlack lightwith a outputat about 360 nm and essentiallnyo outputbelow 300 mm. The temperatureof the reactorwas controlledat 23 3 *C by circulatintgap water. Photolyzatesamples were collectedafterirradiation intervalsof 0, 3,7, 15, and 30 days. Collectedsampleswere removed throughthe reactordrainportand were refdgerateduntilanalyz4 i Analysisof Rhotoproductsby TLC-Autoradiog@2hy A 100 ml aliquotof the0 and 30 day photolyzatesampleswere concentratedwith a rotaryvacuum evaporatorand a water bath todryness,redissolveidn 3 ml of methanol, and transferrewdith two 3 ml washings intoKudema-Danish concentratortubes.Each solutionwere flirthecroncentratedto 1 ml. A 10 ul aliquotof each sample (equivalentto I ml of the originaplhotolyzatesolutionw)as transferreodnto a Thin Layer Chromatography (TLC) plateusing a 10 ul syringe..E*arh platewas developed two-dimensionallwyith ethyl acetatelacetaicid (95/5) followed by ethyl acetatelchloroform/formaiccid/water(65/20/10/5).After air drying,the spots were scraped and quantifiedforradioactivcearbon. Andysis ofPhotoproductsby Gas Chromatognhy Photolyzatesamples from days 0 and 30 were analyzedby acidifying2.0 ml of each in a 4-dram vialwith 0.2 ml- of concentrateHdCI and extractinwgith two 2 ml portionsof diethylether. The -combined extractsof each sample were concentratedto 0.1 ml in a 10-mi Kudema-Danish concentrator tube using a nitrogenpurge. The concentrated'samplewsere methylatedwith 0.4 ml of diazomeflme methylatingsolutionand mixed well. Using a 10 ul syringe,6 ul of sample (equivalento 1.5 ug of the compound of interestw)as injectedv,ia on-column injectioant150 *C,intoa Model 7620 Hewlett-Packardgas chromatograph with a 6 ftX 1/8 in.O.D. stainlesssteelpacked column with 5% OV-17 siliconeon Chromosorb G support.The GC column oven was temperatureprogrammed from 60 to 150 *C at 15 *C/min. Analytes were detected with a microwave sustainedhelium plasma detectorfrom Applied Chromatography Systems Limited, Luton,England. The detectorwas operatedin thefluorinaend sulfurmodes simultaneouslywith outputs toa dual-penrecorder. Results No photodegmdation productswere detectedinthisstudy.Similarradiocarbonassays (withgood analyterecoveries)and similargas chromatograms were obtainedfrom the0 and 30 day samples. JWy 22, 1999 i-A TECHNICAL REPORT. SUMMARY TO:TECHNICAL COMMUNICATIONS CENTER - 2Ol-3CN Oau 1-9-79 'Importa-ntIfreparitsprintoadnbo* sfdaofp*w, und t" copfatsoTCC.J :3ivwon Dept r4urnbW P,ojtec Commercial Chemicals Division Agrichemicals Project 3068 rrelon Numbw -loportTift Service to TOSCA 97T6750202 Rqwlt Numbw FC-95/PHOTOLYSIS STUDY USING SIMULATED SUNLIGHT 001 ra -AU-"-MW--orr- R. A. Prokop J. W. Todd .4otMmak Rofwame Agrichemical Request 888 SECURITY00 0 open (C@og@ COWWontw) Cloled (ftecielAudiodudon) CHELSOM REGISTRY amei"" founowo 43953 ma ofran incwdne ci;;M@@ 13 Now OWnksk RopwW C) va (B No KEVWORDS: (Sel4etterms from 3M Thomrm. SugWt odw awlicame twmlj CURRENT 00ACTIVF: Investigate the photolylic stability of irradiation time and identify ahy of FC-95 as majorw@photo a function products. to/Radiography composition vironment s-Chromatography yer/Chromatography otolysis diotracer intillation REPORT AUTRACT*. (200-250words)Thisdnu-stiinformationIsdistributebdy ft Tochnkm Commnicsoon alert3Wws to C*nWny R&D. - Centerm 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 cheomotagraphy of dli-rivatized samples using a microwave plasma detector. The irradiation source produced 300 nm and longer wavelength light to simulate natural sunlight. Informatio@nJaiwp Initial*: FC-95/PHOTOLYSIS STUDY'USING SIMULATED SUNLIGHT INTRODUCTION .It is generally acknowle.dged 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 (Kohlert 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. C8 F 17 so 3 K The major component is the straight-chain C8 but some branched.cbain isomer%s and other homologs also are present. FC-95 Water Solution. A 50 ppm solution of FC-95- 14 C (285 dpm/)ig)was prepared by dissolving 100.0 mg.of,.FC-95in 2 liters of distilled water. The resulting solution had a specific activity of 14,250 dpm/ml (0.0064,pC/ml). 2. Analys13 Instruments/Materials Liquid Scintillation Counter (LSC) Nuclear-Chicago Mark I Rotary Evaporator Btchi Rotovapor R Kuderna-Danish Concentrator 10 ml concentrator tube - Kontes No. K-570050 RI!eifelautxed cwoaltuemrn bath - Kontes No. K-569251 Thin-Layer Chromatography (TLC) plates MERCK Silica Gel 60 F-2540 0.25 mm thickness and 20 x 20 cm size lst 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 - Column - Column temperature- Injector - Detector - Hewlett-Packard Model T620 6 ft,1/8 in od stainless steel packed with 5% OV-LT silicone on CHROMOSORB G suppor*t. 60 to 150 programmed at 150C/min. on-column at*150*C . I microwave sustained helium plasma from Applied Chromatography Systems Limited, Luton, England DIAZALD ETIAZALD is Aldrich Chemical Company's trade name for N-methyl-N-nitroso-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 sulf.onate ester just prior to gas chromatographic analysis.. c8 F 17 so 3 H + (FC-95 acid) CH2N 2 (DAM) 0 C 8 F 1T SO 3CH 3 + N 2t (FC-95 methyl ester) The DAM reagent used must be free of alcohols or the desired reaction product will nottform 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 -3- placed in a 100 ml long-necked distilling flask fitted with a dropping funnel, an efficient condenser and a water bath at 70*C. 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,bottlel 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, Gen6ral Electric Co.). The temperature wa'scontrolled at 23 + 3*C 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 c6nsisted 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, 3v 79 15 and 30 days. The samples wei6 removed through the reactor drain port and were refrigerated until analyzed. 4. Radiocarbon Recovery The photolyzate samples were assayed for racfiocarbonby.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-.dayphotolyzates 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 acetonitril*ewas added and the rotovacting. continued to just dryness *(Acetonitrilewas added to expeditiously remove remaining water as an azeotrope and thereby minimize possible loss of radiocarbon). The samdle solids were dissolved in 3 ml of methanol and quantitatively -4- 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 65-74*C water bath. The tube contents were concentrated to exactly I ml. A 10.0 ul aliquot of each sample concentrate (equivalent to 1.0 ml of the original photolyzate solution) was transferred onto a TLC plate using a 10 ul 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 them..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 scraping the silica gel.from the plate and LSC counting. The results are presented in Tables II and 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-aram vials. Each sample was acidified with 0.2 ml of concentratq.4hydrochloric 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 ul microsyringet6 jul sample portions (equivalent to 1.5 ug 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 presented in Figure 4. -5- This analysis method is unique in that 1) there are only a few microwave 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 preparedv 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 necesoary 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). Therefo're no 31gnificant amount of radiocarbon was volatilized during the photolytis 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 0-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 4). J. W. Todd -6- REFERENCES Crosby, D.G. and Li, M. 1969. He.rbicide 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. Ultra*violet*Radiat:ion,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. Figure 1 Photoreactor Inlet PINS glass envelope F-406L flowsomt bulb Table I Spectral Energy Distribution for a GE F409L Black Light Bulb Wavelength 290 - 300 310 - 320 320 340 340 --360 360.. 386 380 - 400 400 - 500 5-00 600 'Watts Radiated 0.090 0.235 1..410 1.910 2.31u0< Maxim*uu intensity' at bout 360 na .1.680 2.300 0.340 Figure 2 Photograph of TLC Radioautograph, 30-Day FC-95 Photolyzate DS-2 DS-1 Refere nce Samples. pg of FC-95-14C 49250 DPM @ 1not photol@zed) FC-95 Origin Background (All area less spots 1 and 2) DS-1 DS-2 = Developing Solvent 01, ethyl acetate/acetic acid,95/5. = Developing Solvent #2, ethyl acetate /chloroform/ formic acid/water965/20/10/5. Figure 3 Photograph of TLC Radioautograph, O-Day.FC-95 Photolyzate DS-2 DS-2 Reference Samples. ug of FC-q5-l4C 14,200 DPM, @ not.phototyzed- (D Origin 0 Background (All area less spots 1 and 2) DS-1 = Developing Solvent #1, ethyl acetate/acetic acidt95/5. DS-2 = Developing Solvent #2, ethyl acetate/chloroform/formic acid/water,65/20/10/5. 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 DPM(per ml)* Recovery 149430 kog 1 FC-95 Origin. 3 "Backgroundn. Total 13,873 .49 .1,276 15,198 96 0.3 .9 103 The amount of 1.4 C radioactivity on the plate is equivalent to i'mi of the original photolyzate solution. Table III Radiocarbon recovered in O-Day Photoyzate Solution and TLC Plate Scrapings !FIGURE 3) SamBle Solution bPM/ml Relative 149425 1103 Area 1 2 3 TLC Plate Scrapings . Descripti6n DPM(per ml-)* FC-95 Origin. nbackground" Total 1394-65 26 -1,600 15,091 Recovery 93 0.2 11 104 The amount of 14 C radloactivity*on the piate is equivalent to 1 ml of the oeiginal photolyzate solution. t ct 0 Detector Response ct Ti Detector Response., *%b rC.4 ; 4@ r1 "3