This study investigated the biodegradation potential of3-
14C,1
H,1
H,2
H,2
H-perfluorodecanol [CF
3(CF
2)
614CF
2CH
2CH
2OH,
14C-labeled 8-2 telomer B alcohol or
14C-labeled 8-2TBA] by diluted activated sludge from a domestic wastewatertreatment plant under aerobic conditions. After sampleextraction with acetonitrile, biotransformation products wereseparated and quantified by LC/ARC (on-line liquidchromatography/accurate radioisotope counting) with alimit of quantification about 0.5% of the
14C counts appliedto the test systems. Identification of biotransformationproducts was performed by quadrupole time-of-flight massspectrometry. Three transformation products have beenidentified: CF
3(CF
2)
614CF
2CH
2COOH (8-2 saturated acid); CF
3(CF
2)
614CF=CHCOOH (8-2 unsaturated acid); and CF
3(CF
2)
614COOH (perfluorooctanoic acid, PFOA), representing 27,6.0, and 2.1% of the initial
14C mass (
14C counts applied) after28 days, respectively. A transformation product, not yetreported in the literature, has also been observed andtentatively identified as CF
3(CF
2)
614CH
2CH
2COOH (2
H,2
H,3
H,3
H-perfluorodecanoic acid); it accounted for 2.3% of themass balance after 28 days. The 2
H,2
H,3
H,3
H-perfluorodecanoic acid is likely a substrate for
-oxidation, whichrepresents one of the possible pathways for 8-2 telomerB alcohol degradation. The 8-2 saturated acid and 8-2unsaturated acid cannot be directly used as substratesfor
-oxidation due to the proton deficiency in their
-carbon(C
3 carbon) and their further catabolism may be catalyzedby some other still unknown mechanisms. The 2
H,2
H,3
H,3
H-perfluorodecanoic acid may originate either from the majortransformation product CF
3(CF
2)
614CF
2CH
2COOH or fromother unidentified transformation products via multiple steps.Approximately 57% of the starting material remainedunchanged after 28 days, likely due to its strong adsorptionto the PTFE (poly(tetrafluoroethylene)) septa of the testvessels. No CF
3(CF
2)
614CF
2COOH (perfluorononanoic acid)was observed, indicating that
-oxidation of CF
3(CF
2)
614CF
2CH
2COOH did not occur under the study conditions.Several
14C-labeled transformation products that have notyet been identified (each less than 1% of the massbalance) were also observed and together accounted for7% of the total
14C mass balance after 28 days. It is notclear whether these unidentified transformation productswere resulting from further metabolism of 8-2 saturated acidor 8-2 unsaturated acid. The results suggest thatperfluorinated acid metabolites such as perfluorooctanoicacid account for only a very small portion of thetransformation products observed. Also, the observedvolatility and bioavailability of
14C-labeled 8-2 TBA for microbialdegradation was markedly decreased as a result of thepresence of a strongly adsorbing matrix such as PTFE inthe experimental systems. It is apparent that the biologicalfate of 8-2 telomer B alcohol is determined by multipledegradation pathways, with neither
-oxidation nor anyother enzyme-catalyzed reactions as a single dominant(principal) mechanism under the study conditions.