Wildlife and Landscape Science Directorate, Science and Technology Branch, Environment Canada, National Wildlife Research Centre, Carleton University , Ottawa, ON K1A 0H3, Canada.
Environ Sci Technol. 2014 Jun 3;48(11):6184-91. doi: 10.1021/es500169x. Epub 2014 May 13.
Currently there is a scientific debate on whether fluorinated polymers (or copolymers) are a source, as a result of their degradation and subsequent formation, of perfluorinated carboxylic acids (PFCAs) and perfluorinated alkanesulfonates (PFSAs). The present study investigated whether commercially available fluorinated surfactants, such as Scotchgard fabric protector (3M Company), can be metabolically degraded, using a model microsomal in vitro assay (Wistar-Han rats liver microsomes), and with concomitant formation of PFCAs, PFASs, and/or their precursors. The results showed that the main in vitro metabolite from the pre-2002 product was perfluorooctane sulfonamide (FOSA), and coincident with the detection of the major fabric protector components, which contains the N-ethyl-perfluorooctanesulfonyl chemical moiety (C8F17SO2N(C2H5)-); the main in vitro metabolite of the post-2002 product was perfluorobutane sulfonamide (FBSA), which was coincident with the detection of the major fabric protector components, and contains the N-methyl-perfluorobutanesulfonyl chemical moiety (C4F9SO2N(CH3)-). FOSA or FBSA metabolite concentrations increased over the 0-60 min microsomal incubation period. However, concentrations of their small molecule precursors such as alkylated FOSAs or FBSAs were not detectable (<LODs) in these fabric protector original standard solutions. Thus, the FOSA or FBSA metabolites were derived from the copolymer product itself rather than nonreacted reagents in the Scotchgard products. This result is consistent with reports of high concentrations of PFASs detected in the plasma of persons in households where Scotchgard products are heavily used.
目前，科学界对于含氟聚合物（或共聚物）是否会因其降解和随后的形成而成为全氟羧酸（PFCAs）和全氟烷磺酸（PFASs）的来源存在争议。本研究使用模型微粒体体外测定法（Wistar-Han 大鼠肝微粒体），研究了市售含氟表面活性剂（如 3M 公司的 Scotchgard 织物保护剂）是否可以进行代谢降解，并同时形成 PFCAs、PFASs 及其前体。结果表明，来自 2002 年前产品的主要体外代谢物为全氟辛烷磺酰胺（FOSA），与主要织物保护剂成分的检测结果一致，其中含有 N-乙基-全氟辛烷磺酰基化学部分（C8F17SO2N(C2H5)-）；2002 年后产品的主要体外代谢物为全氟丁烷磺酰胺（FBSA），与主要织物保护剂成分的检测结果一致，其中含有 N-甲基-全氟丁烷磺酰基化学部分（C4F9SO2N(CH3)-）。在 0-60 分钟的微粒体孵育期间，FOSA 或 FBSA 代谢物浓度增加。然而，在这些织物保护剂原始标准溶液中，其小分子前体如烷基化 FOSA 或 FBSA 的浓度无法检测到（<LODs）。因此，FOSA 或 FBSA 代谢物来自于共聚物产品本身，而不是 Scotchgard 产品中的未反应试剂。这一结果与在大量使用 Scotchgard 产品的家庭中，人体血浆中检测到高浓度 PFASs 的报道一致。
