Development and Validation of an Analytical Method for Simultaneous Determination of Perfluoroalkyl Acids in Drinking Water by Liquid Chromatography/Tandem Mass Spectrometry

The environmental presence and drinking water contamination of per- and polyfluoroalkyl substances (PFAS) have been reported since the early 2000s. This study seeks to develop a liquid chromatography/tandem mass spectrometry analytical method for the simultaneous determination of 21 perfluoroalkyl acids (PFAAs) in drinking water to support future regulations in Japan. Inter-laboratory tests were conducted in 16 laboratories using different instrument to verify the applicability of the developed method for a wide range of drinking water samples in Japan. Recovery tests of PFAA-fortified tap water samples obtained in each laboratory were conducted at set points of 1 and 10 ng/L. Calibration curve linearity, trueness (recovery), repeatability (RSDr), and reproducibility (RSDR) at these analyte concentrations were calculated using data obtained from the recovery tests. The trueness, RSDr, and RSDR of most PFAA analytes were satisfactory when the recoveries were corrected by 13C-PFAA extraction standards with similar recovery to the corresponding PFAS analytes. The developed analytical method is valid for the quantification of the target PFAAs in drinking water. However, satisfactory PFAA quantification requires recovery adjustment using surrogates with similar recovery characteristics to the PFAA analytes.