Assessing Per- and Polyfluoroalkyl Substances in Fish Fillet Using Non-Targeted Analyses

Per-
and polyfluoroalkyl substances (PFAS) are a class of thousands
of man-made chemicals that are persistent and highly stable in the
environment. Fish consumption has been identified as a key route of
PFAS exposure for humans. However, routine fish monitoring targets
only a handful of PFAS, and non-targeted analyses have largely only
evaluated fish from heavily PFAS-impacted waters. Here, we evaluated
PFAS in fish fillets from recreational and drinking water sources
in central North Carolina to assess whether PFAS are present in these
fillets that would not be detected by conventional targeted methods.
We used liquid chromatography, ion mobility spectrometry, and mass
spectrometry (LC-IMS-MS) to collect full scan feature data, performed
suspect screening using an in-house library of 100 PFAS for high confidence
feature identification, searched for additional PFAS features using
non-targeted data analyses, and quantified perfluorooctanesulfonic
acid (PFOS) in the fillet samples. A total of 36 PFAS were detected
in the fish fillets, including 19 that would not be detected using
common targeted methods, with a minimum of 6 and a maximum of 22 in
individual fish. Median fillet PFOS levels were concerningly high
at 11.6 to 42.3 ppb, and no significant correlation between PFOS levels
and number of PFAS per fish was observed. Future PFAS monitoring in
this region should target more of these 36 PFAS, and other regions
not considered heavily PFAS contaminated should consider incorporating
non-targeted analyses into ongoing fish monitoring studies.