Perfluorinated Carbon Chain Length Drives Uptake of Diverse Per- and Polyfluoroalkyl Substances in Field-Deployed Passive Samplers

Per- and polyfluoroalkyl substances (PFAS) are a group
of compounds
of high concern due to their ubiquity, persistence, and adverse health
impacts. With a diversity of chemical structures and properties, detection
tools are needed to capture as many PFAS as possible. In this study,
a microporous polyethylene tube (MPT) passive sampler was calibrated
for 25 target compounds, 8 suspect PFAS, and extractable organofluorine
(EOF) during 1–2 week deployments in groundwater, freshwater
river, and estuary contaminated by aqueous film-forming foam (AFFF).
Targeted analysis, suspect screening, and EOF were performed on passive
and grab samples to derive sampling rates, Rs. Median measured and fluorine-normalized estimated EOF Rs in groundwater (7.1 vs 8.4 mL day–1 respectively) and river water (55 vs 66 mL day–1 respectively) were within 20% of each other. For suspect PFAS, Rs were similar to targeted PFAS of alike functional
group chemistry and perfluorinated carbon chain length. For example,
for 6:2 and 8:2 FTSAS-sulfoxide, estimated Rs values were 1.8 and 6.0 mL day–1, respectively,
similar to Rs measured for 6:2 and 8:2
FTS of 2.2 and 6.3 mL day–1. These results suggest
that targeted and suspect PFAS and EOF are predictably taken up by
MPT samplers, expanding passive sampling capabilities.