Comprehensive characterization of per- and polyfluoroalkyl substances in wastewater by liquid chromatography-mass spectrometry and screening algorithms

Abstract

Per- and polyfluoroalkyl substances (PFASs) constitute a large category of synthetic environmental pollutants, many of which remain unknown and warrant comprehensive investigation. This study comprehensively characterized PFASs in fluorinated-industrial wastewater by nontarget, quasi-target and target analyses using liquid chromatography-high-resolution mass spectrometry and data-processing algorithms. The algorithms based on characteristic in-source neutral losses and isotopologue distributions were applied to screening and identifying PFASs, while semiquantitative and quantitative analyses were utilized to determine their concentrations and distributions in the wastewater. In total, 175 formulae of PFASs, including traditional, little-known and unknown species were identified and further ascertained in terms of concentrations and distributions. The total concentrations of PFASs in the wastewater were 5.3–33.4 μg mL⁻¹, indicating serious pollution of PFASs. This study not only provides an efficient approach for screening and identification of unknown PFASs, but also presents a practicable and simple way to comprehensively depict environmental pollution signatures of PFASs.