The 43 anionic PFAS, including PFCAs, PFSAs, fluorotelomer carboxylic acids (FTCAs) and sulfonic acids (FTSs), and perfluoroalkyl ether carboxylic acids (PFECAs) and sulfonic acids (PFESAs), and 21 nonfluorinated anionic surfactants were subjected to LC analysis. All these compounds are listed in Table with the abbreviations used in this article. Reagents were purchased from Tokyo Chemical Industry (Tokyo, Japan), Fujifilm Wako Pure Chemical Corporation (Osaka, Japan), Matrix Scientific (Columbia, USA), SynQuest (Alachua, USA), Sigma Aldrich Japan (Tokyo, Japan), and Toronto Research Chemicals (Toronto, Canada), as detailed in Table . For 19 PFAS, reagents were purchased in the form of acid, K salt, or NH4 salt. These acids and salts were dissolved in MeOH at a concentration of 5 mg/L. In addition, seven commercially available mixtures of PFAS were purchased from Wellington Laboratories (Guelph, Canada) with the product names PFAC-MXG, PFAC-MXA, FTC-MIX-B, FTS-3 MIX, PAP-5MIX, New PFC-4MIX, and PFC-PFS MIX (see Table for the components of the mixtures). The concentrations of individual PFASs in the mixtures ranged from 0.2 to 5 mg/L. Carboxylic acids were obtained as pure acids, while alkyl sulfonates and sulfates were sodium salts. These nonfluorinated surfactants were also dissolved in MeOH to obtain a concentration of 5 mg/L.