Discovery of Fluorotelomer Sulfones in the Blubber of Greenland Killer Whales (Orcinus Orca)

Most known per- and polyfluoroalkyl substances (PFAS) bioaccumulate by binding to proteins or partitioning to phospholipids, leading to their prevalence in liver and blood. As a result, efforts to improve PFAS exposure estimates by identifying novel bioaccumulative substances, have focused on these tissues. However, the recent discovery of high concentrations of unidentified extractable organofluorine (EOF) in the blubber of a killer whale (Orcinus orca) from Greenland suggests that some fluorinated substances bioaccumulate preferentially in storage lipids. The present work builds on this initial finding by characterizing EOF in an additional 3 killer whales (2 from Greenland, 1 from Sweden), and then subjecting extracts from all 4 whales to analysis via gas chromatography-atmospheric pressure chemical ionization-ion mobility mass spectrometry. Using collision cross sections, we prioritized features suspected to be highly fluorinated, and then selected 5 for manual annotation. Custom synthesised standards confirmed 10:2 and 12:2 fluorotelomer methylsulfone, 10:2 and 12:2 fluorotelomer chloromethylsulfone, and 6:2 bisfluorotelomer sulfone in all blubber samples from Greenland at concentrations ranging from <0.4-72.5 ng/g, explaining 34-75% of blubber EOF. None of these substances were observable in liver, suggesting preferential accumulation in storage lipids. To the best of our knowledge, this is the first report of fluorotelomer sulfones in wildlife and the first observation of lipophilic, highly fluorinated PFAS.