Evaluation of Solid Phase Adsorption Toxin Tracking (SPATTs) for passive monitoring of Per- and Polyfluoroalkyl Substances (PFAS) using Ion Mobility Spectrometry-Mass Spectrometry (IMS-MS)

Detection and monitoring of per- and polyfluoroalkyl substances (PFAS) in aquatic environments has become a central priority of regulatory agencies as increasing public concern is focused on minimizing PFAS intake. While many methods utilize active sampling strategies (“grab samples”) for precise PFAS quantitation, here we evaluate the efficacy of low-cost passive sampling devices (Solid Phase Adsorption Toxin Tracking, or SPATTs) for spatial and temporal PFAS assessment of aquatic systems. Passive samplers were deployed in North Carolina along the Cape Fear River during the summer months of 2016 and 2017 originally intended for detection of microcystins and monitoring of potentially harmful agal blooms, though this period also coincided with occurrences of PFAS discharge from a local fluorochemical manufacturer into the river. A subset of the samplers deployed in 2016 were analyzed via liquid chromatography coupled with ion mobility spectrometry-mass spectrometry (LC-IMS-MS) for potential PFAS adsorption in 2021, and after encouraging results were obtained from this preliminary data, additional samplers were deployed subsequently in 2022. Results from this study demonstrated that the resin commonly utilized in SPATTs (Diaion HP20) provided effective binding of PFAS and while legacy compounds were observed in moderate abundance across almost all sampling sites (PFHxS, PFOS, PFHxA, etc.), emerging replacement PFAS (e.g., Nafion Byproducts) were predominantly localized downstream from the manufacturer. Furthermore, samplers deployed downstream from the manufacturer in 2022 noted sharp decreases in observed signal for replacement PFAS in com-parison to samplers deployed in 2016 and 2017, indicating mitigation and remediation efforts in the area were able to reduce localized fluorochemical contamination.