Efficient Online TurboFlow Method for Simultaneous\nDetermination of 60 Emerging Per- and Polyfluoroalkyl Substances in\nMilk

Emerging perfluoroalkyl and polyfluoroalkyl\nsubstances (PFASs)\nhave received much attention in recent years. Milk has usually low\nconcentrations of PFASs, but it remains an important PFAS exposure\nroute due to its high consumption. In this study, a method for simultaneous\ndetermination of 60 PFASs in milk was developed by online TurboFlow\nliquid chromatography–tandem mass spectrometry. A pH-dependent\ncold-induced liquid–liquid extraction was developed for precleanup\nand enrichment. Method quantification limits ranged from 0.003 to\n0.500 ng/mL. For PFASs without corresponding isotope-labeled internal\nstandards, Tanimoto coefficient and logP were introduced for the selection\nof internal standards. The matrix spiked recoveries ranged from 47\nto 190%. The method was applied for PFAS analysis in 35 milk samples.\nPFBS, perfluorohexanesulfonic acid, perfluorooctanesulfonic acid,\nPFNS, PFPeA, perfluorooctanoic acid, PFNA, and 6:2 FTS were detected.\nThe developed online TurboFlow method was simple, reliable, efficient,\nand applicable for trace analysis of PFASs in milk.