On-site multi-matrix profiling of per- and polyfluoroalkyl substances using mobile liquid chromatography - mass spectrometry.

This study demonstrates rapid, on-site detection of per- and polyfluoroalkyl substances (PFAS) at a legacy-impacted site along Barilla Rivulet in Cambridge, Tasmania, using a mobile liquid chromatography-mass spectrometry (LC-MS) laboratory (lab-in-a-van). Ten key PFAS were monitored in freshwater, soil, and soil pore-water samples, providing an integrated view of their distribution and mobility. Sample collection, on-site preparation, and LC-MS analysis of standards and 13 environmental samples were finished within six hours. The compact LC-MS system, pallet-framed in a van, combines a Versiti liquid chromatograph with a Shimadzu autosampler and single quadrupole mass spectrometer. The system was transported from Victoria to Tasmania, where on-site analysis was conducted using an LC-MS method with a total run time of <8 min and limits of detection (LODs) ranging from 0.06 to 0.84 µg/L. Inter-day precision showed %RSD ≤18.3%, and on-site analysis of a certified proficiency test soil sample yielded deviations of 4-35% relative to reference values. Freshwater samples from Barilla Rivulet and soil pore-water samples collected via a ceramic pore-water sampler were processed using a rapid solid-phase extraction (SPE) protocol, completed in 30 min per batch of 3-5 samples, while soil samples were extracted using a solid-liquid extraction (SLE) protocol. The combined concentration of the targeted PFAS ranged from 1.5-2.4 µg/L in freshwater samples, 5.9-22.9 µg/kg in soil, and 0.3-1.9 µg/L in soil pore-water. Clear distinctions were observed in the distribution of short- and long-chain homologues, as well as between carboxylic- and sulfonic-acid PFAS across soil and soil pore water. This study demonstrates that a rapid multi-matrix PFAS survey can be conducted on-site using mobile LC-MS, providing a practical solution for time-critical environmental assessments and supporting data-driven remediation decisions.