Determination of 56 perfluoroalkyl acids and precursors in top predators and their prey from Northern Europe by LC-MS/MS

Per- and polyfluoroalkyl substances (PFAS) are a class of emerging substances that have proved to be persistent and highly bioaccumulative. They are widely used in industrial and consumer applications and are known for their long-distance migration and toxicity. In this study, 65 recent specimens of a terrestrial apex predator (Common buzzard), freshwater and marine apex predators (Eurasian otter, harbour porpoise, grey seal, harbour seal) and their potential prey (bream, roach, herring, eelpout) from northern Europe (United Kingdom, Germany, the Netherlands and Sweden) were analyzed for the presence of legacy and emerging PFAS, employing a highly sensitive liquid chromatography electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS) method. Fifty-six compounds from fourteen classes were measured; 13 perfluoroalkyl carboxylic acids (PFCAs), 7 perfluoroalkyl sulphonic acids (PFSAs), 3 perfluorooctane sulfonamides (FOSAs), 4 perfluoroalkylphosphonic acids (PFAPAs), 3 perfluoroalkylphosphinic acids (PFPi’s), 5 telomer alcohols (FTOHs), 2 mono-substituted polyfluorinated phosphate esters (PAPs), 2 di-substituted polyfluorinated phosphate esters (diPAPs), 6 saturated fluorotelomer acids (FTAS), 3 unsaturated fluorotelomer acids (FTUAs), 2 N-Alkyl perfluorooctane sulfonamidoethanols (FOSEs), 3 fluorotelomer sulphonic acids (FTSAs), 2 perfluoroether carboxylic acids (PFECAs) and 1 chlorinated perfluoroether sulphonic acid (Cl-PFESA). All samples were lyophilized before analysis in order to enhance extraction efficiency, improve the precision and achieve lower detection limits. The analytes were extracted from the dry matrices through generic methods of extraction, using an accelerated solvent extraction (ASE), followed by clean-up through solid phase extraction (SPE). Method detection limits and method quantification limits ranged from 0.02 to 1.25 ng/g wet weight (ww) and from 0.05 to 3.79 ng/g (ww), respectively. Method accuracy ranged from 40 to 137 %. Method precision ranged from 3 to 20 %RSD. The sum of PFAS concentration in apex predators (liver) ranged from 0.2 to 20.2 μg/g (ww), whereas in the fish species (muscle tissue) it ranged from 16 to 325 ng/g (ww). Our analyses showed that all specimens were primarily contaminated with PFOS, while the three PFPi’s included in this study exhibited FoA 100%. Additionally, C9 to C13 PFCAs were detected at high concentrations in apex predator livers despite phase-outs and increasing regulation of these compounds together with C8-based PFAS. Overall, PFAS concentrations were one to four orders of magnitude higher in predator liver tissues than in fish muscle, suggesting bioaccumulation and biomagnification of PFAS up the food chain. The high variety of PFAS and the different PFAS composition in the AP&P samples is alarming and merits the attention of regulators.