Determination of PFAS in Pea Protein by Fabric Phase Sorptive Extraction Coupled with UHPLC–MS/MS

The growing use of plant-based protein ingredients, particularly pea protein, highlights the need for robust analytical methodologies capable of monitoring emerging contaminants such as per- and polyfluoroalkyl substances (PFAS). In this study, a green and efficient analytical method based on fabric phase sorptive extraction (FPSE) coupled with UHPLC–MS/MS was developed and validated for the determination of four PFAS; perfluorooctanoic acid (PFOA), perfluorooctane sulfonic acid (PFOS), perfluorononanoic acid (PFNA), and perfluorohexane sulfonic acid (PFHxS) in pea protein. The FPSE protocol was optimized to address the challenges associated with high-protein matrices, minimizing matrix effects while ensuring high extraction efficiency. The method demonstrated excellent linearity (R2 > 0.9910) over the range 0.05–10 μg/kg with limits of detection and quantification ranging from 0.003 to 0.020 μg/kg and 0.010 to 0.060 μg/kg, respectively. Recoveries ranged from 96 to 107%, while repeatability (expressed as relative standard deviation) was below 7.8%, confirming the method’s accuracy and precision. The validated method was applied to eleven commercial pea protein samples, where PFOA was detected in nine out of eleven samples at concentrations between 0.01 and 2.76 μg/kg, whereas PFNA was detected in one sample and PFOS and PFHxS were not detected. The proposed method provides a robust and environmentally friendly tool for the determination of PFAS in plant-based protein matrices, contributing to improved food safety monitoring and supporting future risk assessment studies.