LC-HRMS analysis of ultrashort- and short-chain PFAS on porous graphitic carbon column and study of accumulation in plants.

Abstract

In this study, a robust LC-HRMS (QTOF) method was developed for the simultaneous determination of ultrashort- and short-chain perfluoroalkyl substances (PFAS) in complex plant matrices using a porous graphitic carbon column. The method enabled sensitive and selective detection of seven PFAS (C2-C10) in 18 min, including trifluoroacetic acid (TFA), which is known to exhibit poor retention on conventional C18 phases. The retention behavior of the analytes was systematically investigated under isocratic and gradient conditions, revealing a non-linear dependence on methanol content. Based on these findings, an optimized gradient elution program was proposed, ensuring excellent separation and peak shape even when injecting methanol-rich plant extracts-one of the advantages of porous graphitic carbon columns. Calibration curves for all analytes demonstrated good linearity (R² > 0.99) over relevant concentration ranges with accuracy within ± 15%. The method showed good recovery (71-103%) and precision (RSD < 7%) in rapeseed and burr medic methanolic extracts. Application to real plant samples exposed to PFAS-contaminated media (10 µg/mL) revealed substantial accumulation of ultrashort-chain PFAS, especially TFA and perfluoropropionic acid (PFPrA). These results support the potential of plant-based remediation strategies and highlight the importance of monitoring short- and ultrashort-chain PFAS in environmental and agricultural systems.