Human
exposure to per- and polyfluoroalkyl substances (PFAS) through
the US diet has not been well-characterized. Highly consumed foods
are routinely monitored through FDA’s Total Diet Study program.
Portions of these samples were used to develop and validate a method
for PFAS in a wide variety of foods. The extraction of 16 PFAS was
performed using the quick, easy, cheap, effective, rugged, and safe
(QuEChERS) method and analyzed by liquid chromatography/mass spectrometry.
Method optimizations are described including investigations into the
QuEChERS sorbents, matrix effects, and solid-phase extraction (SPE)
cartridges. The use of a custom push-through SPE cartridge showed
promising results as a rapid cleanup option for food samples. Challenges
in ion confirmation are discussed, and the use of enhanced product
ion (EPI) full-scan MS/MS spectra is presented as a potential option
for verifying false positives. The validated method was then used
for the analysis of 179 total diet study samples, and positive detects
for perfluorooctanesulfonic acid (PFOS) were found in two fish and
one meat sample.