Utilizing Pine Needles to Temporally and Spatially Profile Per- and Polyfluoroalkyl Substances (PFAS)

As concerns over exposure to per-
and polyfluoroalkyl substances
(PFAS) are continually increasing, novel methods to monitor their
presence and modifications are greatly needed, as some have known
toxic and bioaccumulative characteristics while most have unknown
effects. This task however is not simple, as the Environmental Protection
Agency (EPA) CompTox PFAS list contains more than 9000 substances
as of September 2020 with additional substances added continually.
Nontargeted analyses are therefore crucial to investigating the presence
of this immense list of possible PFAS. Here, we utilized archived
and field-sampled pine needles as widely available passive samplers
and a novel nontargeted, multidimensional analytical method coupling
liquid chromatography, ion mobility spectrometry, and mass spectrometry
(LC-IMS-MS) to evaluate the temporal and spatial presence of numerous
PFAS. Over 70 PFAS were detected in the pine needles from this study,
including both traditionally monitored legacy perfluoroalkyl acids
(PFAAs) and their emerging replacements such as chlorinated derivatives,
ultrashort chain PFAAs, perfluoroalkyl ether acids including hexafluoropropylene
oxide dimer acid (HFPO–DA, “GenX”) and Nafion
byproduct 2, and a cyclic perfluorooctanesulfonic acid (PFOS) analog.
Results from this study provide critical insight related to PFAS transport,
contamination, and reduction efforts over the past six decades.