A fast method for analysing six perfluoroalkyl substances in human serum by solid-phase extraction on-line coupled to liquid chromatography tandem mass spectrometry

We have developed and validated an on-line TurboFlow solid-phase extraction procedure coupled to high-performance liquid chromatography with tandem mass spectrometry for the analysis of six perfluoroalkyl substances (PFAS), two sulfonates (perfluorooctane sulfonate and perfluorohexane sulfonate), three carboxylates (perfluorooctanoic acid, perfluorononanoic acid and perfluorodecanoic acid), and one sulfonamide (N-methylperfluorooctane sulfonamide), in human serum samples. This method requires only 100 μL of sample and involves a short pre-treatment with acetonitrile followed by addition of a labelled internal standard for quantification and ultracentrifugation. All PFAS were detected with a run time of 8.5 min. Linearity ranges stay between 0.1 and 20 μg L−1 (R2 > 0.9960). Recoveries were determined by spiking blank serum samples with a mixture of six PFAS and found to be in the range 96–110 % for all compounds. Isotopic dilution was used to quantify the selected analytes. The low limits of quantification obtained, between 0.16 and 0.34 μg L−1, small volume of sample required and short run time used (from two to three times shorter than any other described method), make this validated method highly recommended for human biomonitoring studies.