Identification of Novel Polyfluorinated Ether Sulfonates as PFOS Alternatives in Municipal Sewage Sludge in China.

ABSTRACT

A 62 chlorinated polyfluorinated ether sulfonate (62 Cl-PFAES) with the trade name F-53B, is an alternative to perfluorooctanesulfonate (PFOS) in electroplating industry that is uniquely used in China. It was developed as a mist suppressant initially in the 1970s, but the environmental behaviors and potential adverse effects of the 62 Cl-PFAES have only recently been investigated. In this work, the occurrence and distribution of perfluoroalkyl sulfonate (PFSA), fluorotelomer sulfonate (FTSA), and PFAES analogues were investigated in municipal sewage sludge samples collected around China. Perfluorobutane, perfluorohexane, perfluorooctane, and perfluorodecanesulfonates, 62 and 82 FTSAs, and the emerging 62 Cl-PFAES were detected. Moreover, 82 and 102 Cl-PFAESs were identified for the first time as new polyfluorinated contaminants using high resolution mass spectrometry. These fluorinated analytes were further quantified with the aid of commercial and laboratory-purified standards. PFOS was the predominant contaminant with a geometric mean (GM) value of 3.19 ng/g dry weight (d.w.), which was subsequently followed by 62 Cl-PFAES and 82 Cl-PFAES (GM 2.15 and 0.50 ng/g d.w., respectively). Both 62 and 82 Cl-PFAES were positively detected as the major components in the F-53B commercial product, and discrete 62 Cl-PFAES/82 Cl-PFAES ratios in the product and sludge samples might suggest 82 Cl-PFAES had enhanced sorption behavior in the sludge due to the increase in hydrophobicity.