Per- and Polyfluorinated Alkyl Substances in Different Water Matrices: Nontargeted Analysis, Suspect Screening, and Targeted Analysis

Abstract

This study investigated the presence of unknown and known PFAS in wastewater treatment plants, drinking water treatment plants, bottled water, tap water, and surface water using both high-resolution and tandem mass spectrometry. The sources of PFAS in these matrices were elucidated via a multivariate statistical analysis. A total of 70 PFAS features were identified using nontargeted analysis at varying confidence levels. For the first time in South Africa, and probably on the African continent, novel PFAS (MeFOSA, EtFOSA, 6:2 FTUCA, 8:2 FTUCA, 6:2 FTCA, 8:2 FTCA, 10:2 FTCA, PFHxI, PFOI, 8:2 FTAC, 6:2 FTMAC, and 8:2 FTMAC) and emerging PFAS (PFMOPrA, PFPrOPrA, PFO2HxA, PFO3OA, and PFO4DA) were detected and reported in various water sources. The sum of ∑21 PFAS concentrations in bottled water, tap water, surface water, DWTP, and WWTP samples ranged from <LOD-126, <LOD-363, <LOD-716, <LOD-1056, and <LOD-2304 ng/L, respectively. The average concentrations of PFOA, PFOS, PFNA, and PFHxS in drinking tap water exceeded their respective US EPA maximum contaminant levels. PFO2HxA, PFO4DA, and PFO3OA were reported for the first time in drinking water, with PFAS displaying potential similarities in sources. This study underscores the importance of PFAS regulation in drinking water in South Africa to safeguard public health.