Document ypZeNDD7kmZpRZqzmDzQXY7j6

AR226-3350 Biotransformation of the 14C-labeled Fluorotelomer 8-2 Telomer B Alcohol* Wang N.1. Szostek B2, Folsom P.W. \ Capka V.2, Sulecki L.1, Berti W.R.1, Gannon J.T.1, and Buck R.C.3 1 DuPont Central Research and Development, Wilmington, DE, USA; 2 DuPont Haskell Laboratory, USA; 3 DuPont Chemical Solutions Enterprise, U SA 8-2 Telomer B Alcohol: C8F17CH2CH2OH (8-2 TBA; CAS# 678-39-7) Background Information A key raw material used in the manufacture o f sales products. May be a transformation product o f fluorotelomer based sales products. Kev Questions Is it biotransformable? Under what conditions ? What are the major transformation products ? What are the likely biotransformation pathways ? Physical Properties and Purity of the Test Substance "A Difficult to Test Substance" * Low solubility 150 p g L '1 Vapor pressure 3 Pa at 21 C Adsorption to surfaces A Chromatogram of HPLC Characterization of Radiochemical Purity of the Test Substance > Virtually 100% purity Time (min) EXPERIMENTAL METHODS Modified OECD 301D Closed Bottle Test. Experimental System: Closed bottles (30 mL of test substance solution in 120-mL glass serum bottles crimp-sealed with PTFE septa). Concentration of the test substance: 337 pg L/1dispersed in mineral medium. Additional organic carbon source: 13 mg L*1of ethanol (as co solvent). Inoculum: Fresh sludge from Municipal POTW (Non-acclimated, 5 mL sludge L_I test solution, ~ 104cells). Experimental Duration: 28 days at room temperature. EXPERIMENTAL METHODS (Continued) Analytical methods: Sample extraction: Acetonitrile for l4C-labeled parent and transformation products; alkaline lysis for fluoride ion. Parent (F(CF2)8CH2CH20H) was quantified by GC/MS and fluoride ion by ion selective electrode. LC/ARC (On-line liquid chromatography/accurate radioisotope counting) was used for separation and quantification o f 14C-labeled parent and transformation products, identification o f the transformation products was conducted by Q-TOF-MS method. Spike recovery o f l4C-labeled parent and cold standard fluorinated acids from the sample matrices was analyzed by liquid scintillation counting and LC/MS/MS, respectively. RESULTS Spike recovery of F (C F 2)7!4C F 2C H 2C H 2O H a n d o th er standard fluorinated acids from the sample matrices Substance spiked (dosed) % Recovery* F(CFj)7kCF2CH2CHjOH f (c f 2)7c f 2c h 2c o o F(CF2)7CF=CHCOOF(CF2)7COOFtCFj^COO 92 7 100 20 81 21 104 14 120 11 *: Average value for days 0,7,14 and 28. t This research was partially funded by the Telomer Research Program (TRP), participating companies include Asahi Glass, Clariant GmbH, Daikin Industries and E.I. duPont de Nemours & Company. 5 j D ay 28 bio d eg rad atio n sam ple - m ethod 2 4 1 i ^ ' ` ` ' W -- 4 -- -- $; liV____ Peaks 1 ,2 ,3 , & 4 are observed transformation products and peak 5 is the parent ..vi S..M.... wsrew ______________ ! * i Day 28 abiotic control-m ethod I P arent (Abiotic control - 5 mL autoclaved sludge L-` test solution + 0.S mM NaCN) ^ The miracles o f science' Biotransfrmation of the 14C-labeled Fluorotelomer 8-2 Telom er B Alcohol ? (Continued) Identification of Transformation Products LC/ARC Peak 1-415 m/z Parent: CF3(CF2)i urOO- LC/ARC Peak 2 - 459 m/z Parent: CFj(CF i)s, 'C F*CHCOO- LC/ARC Peak 3 - 443 m/z Parent: C7HjF]3-I',CFICHiCOO- (Proposcd molccnlar formula) LC/ARC Peak 4 - 479 m/z Parent: CF3(CFjV 'C F 2CHjCOO- Daughter ion spectra of ions obtained for day-28 sample by Q-TOF-MS 7 Accurate Mass Measurement for Observed Transformation Products Determined mass 478.9803 14C-labeled transformation products CF3(CFj)6C F2CHjCOO- Elemental composition 12C 9 14C H2 0 2 F17 Calculated mass 478.9816 Error in ppm -2,6 458.9764 CF3(CFj)6,4CF= CHCOO- 1 2 C 9 1 4 C H 0 2 F16 458.9753 +2.3 414.9771 CFj(CFj)4mCOO- 12C 7 14C 0 2 F15 414.9691 +19.3 443.0037 C7Hj F|3,4CF2CHjCOO" 12C914C H4 02F15 443.0004 +7.4 8 Mass Balance of Transformation Products at Day 28 Transformation Products % Total Peak 1 - F(CF2) , 14COO2 - F(CF2) , l4CF=CHCOO3 - CvH2F ,314C F2CH 2COO 4 - F(CF2)7I4C F 2CH 2COO 5 - F(CF2) , 14CF2CH2CH2OH (parent) F(CF2)714C F 2CH2CH2OH (parent) adsorbed by the test vessel surface Sum 2.0 5.9 2.3 26.6 16.1 ~40 93* : Estimated. *: Other unidentified minor transformation products together accounted for < 10% o f mass balance, with each o f them accounted for < 1% o f mass balance. " 10 Potential Biotransformation Routes (Not include the unidentified minor transformation products) proposed F(CF2)7" CF2CH2CH2OH C7H 2F 13I4CF2CH 2COO- F(CF2)714CF2CH2COO 1 1........... proposed F(CF2),14CF=CHCOO- + f - +2F- l l -------------------- * - * F(CF2)7I4COO- + f- H (Other fluorinated substances ?) il Time Course of 14C-labeled Transformation Product Formation CP3!CF2)S14CF2-CH2COO- CF3(CF2)814CFCHCOO- R CF3(CF2)614COO- :.:C7H2F1314CF24X2COO- | (14C4^e- -----V 1 n 28 Days after the initiation Graph B - Zoom view of graph A Graph C - Stack chart plot o f graph A CONCLUSIONS Four biotransformation products (F(CF2)7]4CF2CH2COO", F(CF2)7,4CF=CHCOO', C7H2F!314CF2CH2COO', and F(CF2)714COO_) were formed over the 28 days; the concentration o f the transformation products did not reach steady-state. It cannot be concluded from this study whether these are the ultimate products of biotransformation. The observed transformation product C7H2F13l4CF2CH2COO- accounted for 3.8% o f remaining1JC radioactivity in the test solution at day 28. The formation and increase o f this product over 28 days indicated that biotransformation pathways for F(CF2)714CF2CH2CH2OH most likely diverged at the point of the parent (itself) or F(CFj)7I4CF2CH2COO-, with one transformation path proceeding through F(CF2)7,4COO~ (PFOA) and an alternative path proceeding through CtHjF ^^C F jCHjCOO-. PFOA formation will not occur through the alternative path. Although PFOA is one o f the identifiable metabolites, it accounted for approx. 2% o f mass balance at day 28. Biotransformation ofF(CF2)714CFiCH2CH2OH may be facilitated by the presence o f ethanol (13 mg L*1) as a co-solvent. 12 The miracles o f science-