The structure of the fire fighting foam surfactant Forafac®1157 and its biological and photolytic transformation products

• Published in: Chemosphere (Oxford) Vol. 89; no. 7; pp. 869 - 875
• Main Authors: Moe, Morten K., Huber, Sandra, Svenson, Johan, Hagenaars, An, Pabon, Martial, Trümper, Monika, Berger, Urs, Knapen, Dries, Herzke, Dorte
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01.10.2012; Elsevier
• Subjects: 19F NMR; AFFF; Alkanesulfonic Acids - analysis; Alkanesulfonic Acids - metabolism; Animal, plant and microbial ecology; Animals; Applied ecology; Applied sciences; Biological and medical sciences; Earth sciences; Earth, ocean, space; Ecotoxicology, biological effects of pollution; Engineering and environment geology. Geothermics; Exact sciences and technology; F-19 NMR; Flatfishes - metabolism; Fluorocarbons - analysis; Fluorocarbons - metabolism; Fluorotelomer sulfonamide alkylbetaine; Fundamental and applied biological sciences. Psychology; General aspects; Global environmental pollution; In vivo transformation; Magnetic Resonance Spectroscopy; Mass Spectrometry; Mytilus edulis - metabolism; Photolysis; Photolytic transformation; Pollution; Pollution, environment geology; Soil Pollutants - analysis; Soil Pollutants - metabolism; Surface-Active Agents - analysis; Surface-Active Agents - metabolism; Ultraviolet Rays; Fluorotelomer sulfonamide alkylbetaine; PT; FTOH; Photolytic transformation; COSY; M; 19F NMR; HRMS; ESI; QTOF; HPLC; gHMBC; MS; CAD; PCB; POP; PFCA; In vivo transformation; NMR; PAH; AFFF; FTSA; 6:2 FTAB; NL; PFOS; Scophthalmus maximus; Firefighting; Mytilus edulis; Metabolite; Toxicity; Surfactant; Telomere; Bivalvia; Pisces; Biotransformation; Organic compounds; Photochemical degradation; Sulfonamide; Ecotoxicology; Pollutant behavior; Vertebrata; F NMR; Foam; Environment impact; Organic fluorine compounds; Invertebrata; Mollusca; Degradation product
• ISSN: 0045-6535; 1879-1298; 1879-1298
• DOI: 10.1016/j.chemosphere.2012.05.012

► The structure of 6:2 FTAB (Forafac®1157), a PFOS replacement, is reported here. ► 6:2 FTAB was metabolized by turbot and mussel, and transformed by photolysis. ► In all experiments, the most abundant product was a deacetylated species. ► Additional demethylation was also observed, as well as a fluorotelomer sulfonamide. ► 6:2 FTAB and its metabolites should be included in future monitoring activities. For several decades, perfluorooctane sulfonate (PFOS) has widely been used as a fluorinated surfactant in aqueous film forming foams used as hydrocarbon fuel fire extinguishers. Due to concerns regarding its environmental persistence and toxicological effects, PFOS has recently been replaced by novel fluorinated surfactants such as Forafac®1157, developed by the DuPont company. The major component of Forafac®1157 is a 6:2 fluorotelomer sulfonamide alkylbetaine (6:2 FTAB), and a link between the trade name and the exact chemical structure is presented here to the scientific community for the first time. In the present work, the structure of the 6:2 FTAB was elucidated by 1H, 13C and 19F nuclear magnetic resonance spectroscopy and high-resolution mass spectrometry. Moreover, its major metabolites from blue mussel (Mytilus edulis) and turbot (Scophthalmus maximus) and its photolytic transformation products were identified. Contrary to what has earlier been observed for PFOS, the 6:2 FTAB was extensively metabolized by blue mussel and turbot exposed to Forafac®1157. The major metabolite was a deacetylated betaine species, from which mono- and di-demethylated metabolites also were formed. Another abundant metabolite was the 6:2 fluorotelomer sulfonamide. In another experiment, Forafac®1157 was subjected to UV-light induced photolysis. The experimental conditions aimed to simulate Arctic conditions and the deacetylated species was again the primary transformation product of 6:2 FTAB. A 6:2 fluorotelomer sulfonamide was also formed along with a non-identified transformation product. The environmental presence of most of the metabolites and transformation products was qualitatively demonstrated by analysis of soil samples taken in close proximity to an airport fire training facility.