Retrospective Identification of Novel and Legacy Per- and Polyfluoroalkyl Substances in German Archived Fish Livers Using a Combined High-Resolution Mass Spectrometry Approach

Per- and polyfluoroalkyl substances (PFAS) are persistent
environmental
pollutants with many unknown variants, posing potential ecosystem
and human health risks. To comprehensively assess PFAS contamination
and overcome the challenge of unknown PFAS identification, we combined
Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR
MS) and liquid chromatographyquadrupole time-of-flight mass
spectrometry (LC-QTOF MS) to identify novel and Legacy PFAS in archived bream liver samples collected in Germany between
1996 and 2020. By leveraging the ultrahigh resolution and mass accuracy
of FT-ICR MS, we generated a mass list for cross-comparison with common
precursor ion features from LC-QTOF MS. We identified 78 PFAS, including
68 classified into 12 homologue groups and 10 that did not fit into
any homologue series, encompassing perfluoroalkyl acids, fluorotelomer-based
substances, pentafluorosulfide perfluoroalkyl sulfonic acids, polyfluoroalkyl
sulfinates, polyfluoroalkyl sulfonyl sulfonamides, and other novel
compounds including ionic liquids. Spatial and temporal analysis revealed
that perfluoroalkyl phosphinic acids (C6/C6, C6/C8) and polyfluoroalkyl
sulfonic acids (n = 10) have a widespread presence, whereas tris(pentafluoroethyl)trifluorophosphate
(FAP) and polyfluoroalkyl sulfonyl sulfonamides (n = 6) are more localized
or have only recently emerged in specific regions. These findings
underscore the need for continued monitoring to comprehensively understand
exposure to PFAS and their long-term environmental impact.