Perfluorooctanesulfonamide

The molecular structures of the 14 PFAS evaluated are in Figure S1 and physiochemical properties, such as molecular weight (MW) and logD shown in Table S1. The following fourteen PFAS were either obtained from Accustandard, Inc. (New Haven, CT, USA) or Sigma-Aldrich (St. Louis, MO, USA): Perfluorobutanoic acid (PFBA), perfluoropentanoic acid (PFPA), perfluorohexanoic acid (PFHxA), perfluoroheptanoic acid (PFHpA), perfluorooctanoic acid (PFOA), perfluorononanoic acid (PFNA), perfluorodecanoic acid (PFDA), perfluoroundecanoic acid (PFUDA), perfluorododecanoic acid (PFDoDA), perfluorohexanesulfonic acid (PFHxS), perfluorooctanesulfonamide (PFOSA), 6:2 fluorotelomer sulfonate (6:2 FtS), perfluorobutanesulfonic acid (PFBS), and perfluorooctanesulfonic acid (PFOS). Human, rat (Wistar-Han), and mouse (CD-1; C57BL/6) equal sex pooled (minimum of 3 male and 3 female) plasma was obtained from BioIVT (Hicksville, NY, USA). The equilibrium dialysis device (HTD96) and cellulose membranes with a molecular weight cutoff of 12–14 kDa were obtained from HTDialysis, LLC (Gales Ferry, CT, USA). Human, rat, and mouse albumin, along with all other reagents were obtained from Sigma-Aldrich unless specified otherwise.

PFCAs (>98% purity) were purchased from Sigma-Aldrich Inc. and included perfluorobutanoic acid (PFBA), perfluoropentanoic acid (PFPeA), perfluorohexanoic acid (PFHxA), perfluoroheptanoic acid (PFHpA), perfluorooctanoic acid (PFOA), and perfluorononanoic acid (PFNA). A precursor of PFOA, perfluorooctane sulfonamide (PFOSA, 98%) was also obtained from Sigma-Aldrich Inc. Dicyclohexylcarbodiimide (DCC) and 3, 4-dichloroaniline (DCA) were purchased from J&K Scientific Ltd (Beijing, China). SPE silica-gel columns (Cleanert Pesticarb-SPE cartridge) were provided by Bonna-Agela Technologies Inc (Tianjin, China). Ultrapure water (18.2 MΩ/cm, Hitech, China) was used for aqueous sample preparation. Possible contamination was avoided by verifying all solids and solvents with procedural blanks in advance.