Direct injection analysis of per and polyfluoroalkyl substances in surface and drinking water by sample filtration and liquid chromatography-tandem mass spectrometry

We developed and validated a method for direct determination of per-and polyfluoroalkylated substances (PFASs) in environmental water samples without prior sample concentration. Samples are centrifuged and supernatants passed through an Acrodisc Filter (GXF/GHP 0.2 um, 25 mm diameter). After addition of ammonium acetate, samples are analyzed by UPLC-MS/MS using an AB Sciex 6500 plus Q-Trap mass spectrometer operated in negative multiple reaction-monitoring (MRM) mode. The instrument system in-corporates a delay column between the pumps and autosampler to mitigate interference from background PFAS. The method monitors eight short-/long-chain PFAS which are identified by monitoring specific pre -cursor product ion pairs and by their retention times and quantified using isotope mass-labeled internal standard based calibration plots. Average spiked recoveries ( n = 8) of target analytes ranged from 84 to 110% with 4-9% relative standard deviation (RSD). The mean spiked recoveries ( n = 8) of four surrogates were 94-106% with 3-8% RSD. For continuous calibration verification (CCV), average spiked recoveries ( n = 8) for target analytes ranged from 88 to 114% with 4-11% RSD and for surrogates ranged from 104- 112% with 3-11% RSD. The recoveries ( n = 6) of matrix spike (MX), matrix spike duplicate (MXD), and field reagent blank (FRB) met our acceptance criteria. The limit of detection for the target analytes was between 0.007 and 0.04 ng/mL. The method was used to measure PFAS in tap water and surface water. (c) 2021 Elsevier B.V. All rights reserved.

Automated summary

A method for direct determination of PFASs in environmental water samples without prior sample concentration was developed and validated. The method involves UPLC-MS/MS analysis with isotope mass-labeled internal standard-based calibration plots, achieving good recoveries.