On-line solid phase extraction-ultra high performance liquid chromatography-quadrupole/Orbitrap high resolution mass spectrometry determination of per- and polyfluoroalkyl substances in human serum.

A rapid, high-performance, and accurate on-line TurboFlow ultra high performance liquid chromatography-quadrupole/Orbitrap high resolution mass spectrometry method was developed for the analysis of 46 per- and polyfluoroalkyl substances (PFAS), including 17 perfluoroalkylcarboxylic acids, 15 perfluoroalkylsulfonates, 3 fluorinated telomer sulfonates, 2 perfluoroalkyl unsaturated carboxylates, 2 perfluorooctanesulfonamidoacetic acid, 3 perfluorooctanesulfonamides, hexafluoropropylene oxide-dimer acid, ammonium 4,8-dioxa-3H-perfluorononanoate, 6:2 chlorinated polyfluorinated ether sulfonate (Cl-PFESA), and 8:2 Cl-PFESA, in human serum. The TurboFlow column, mobile phase, sample injection volume, loading flow rate, and elution time were optimized. The linearities of matrix calibration curves, method limits of quantification, accuracy and precision were investigated for method validation. Serum samples (50 μL) were precipitated with acetonitrile and directly injected into the system. The method showed good linearity (R > 0.99), satisfactory recoveries (matrix-spiked recoveries range: 68.9%-115.7%), good precision (relative standard deviation ranges: 1.2%-12.1%) and a low method limit of quantification (0.1-1 ng mL). The developed method is rapid, accurate and convenient for large-scale biomonitoring of PFAS in humans. Fifty real serum samples from China were analyzed and the results showed that br-perfluorooctanesulfonate (PFOS) accounted for approximately 30% of the ∑PFOS in serum, which suggested there was high exposure to 6:2 Cl-PFESA.