Evan Walters

The accurate analysis of per- and polyfluoroalkyl substances (PFAS) in various environmental matrices relies on efficient sample preparation techniques, particularly solid phase extraction (SPE). This study evaluates the performance of SPE sorbents relevant to Environmental Protection Agency (EPA) Methods 537.1, 533, and 1633, focusing on divinylbenzene (DVB), weak anion exchange (WAX), graphitized carbon black (GCB), as well as stacked and blended sorbent configurations. Key factors affecting PFAS recovery and analytical performance were investigated across potable water, non-potable water, and solid samples. Results indicate that DVB particle size influences extract composition and peak asymmetry in EPA Method 537.1, while WAX SPE media particle size impacts the detection of neutral PFAS in EPA Method 1633. Furthermore, comparisons between WAX/GCB stacked and blended media for EPA Method 1633 highlight performance in various matrices. Finally, we explore Solid Phase Extraction (SPE) cleanup techniques for processing solid matrices, addressing common challenges for low EIS recoveries for d7-NMeFOSE, d3-NMeFOSA, d9-NEtFOSE, and d5-NEtFOS. This work demonstrates the importance of selecting appropriate SPE conditions to enhance sample processing and analytical performance to improve PFAS quantification in environmental samples.