Effect of Sorbent Amount in Weak Anion Exchange Solid-phase Extraction Cartridges on PFAS Analysis in Seawater: Application to Short-chain PFAS

Abstract

Per- and polyfluoroalkyl substances (PFAS) are persistent and resistant to degradation, and understanding their distribution in aquatic environments is of great importance. In particular, seawater samples contain high concentrations of salts, which can cause matrix effects during solid-phase extraction (SPE) and liquid chromatography–tandem mass spectrometry (LC-MS/MS) , making the retention of short-chain PFAS challenging. In this study, the effect of the sorbent amount in weak anion exchange (WAX) solid-phase extraction cartridges on PFAS recoveries in seawater was investigated, and the applicability of the method to the simultaneous analysis of a wide range of PFAS, including short-chain compounds, was evaluated. In a sorbent amount comparison test using 100 mL of seawater spiked with ¹³C-labeled PFAS, the 1000 mg condition showed the most favorable absolute recoveries among the three conditions evaluated, with recoveries ranging from 54.0% to 110%. In the spike recovery test using Ise Bay seawater spiked with native PFAS, surrogate-corrected recoveries ranged from 72.0% to 115%, with relative standard deviations (RSDs) of 3.7–10.6%, method detection limits (MDLs) of 0.13–0.36 ng L^-1, and method quantification limits (MQLs) of 0.33–0.94 ng L^-1. Overall, these results indicate that the proposed method is applicable to the analysis of a wide range of PFAS, including short-chain compounds, in seawater samples and may be useful for marine environmental monitoring.