Optimization for the analysis of 42 per- and polyfluorinated substances in human plasma: A high-throughput method for...

There is an increasing awareness about the presence of per- and polyfluoroalkyl substances (PFAS) in many environmental and biological compartments, including human biofluids and tissues. However, the increase of PFAS replacements, including alternatives with shorter chain or less bioaccumulative potential, has broaden the exposure and the need for wider identification procedures. Moreover, the low volumes available for human blood or plasma, and the high number of samples needed to assess adequately epidemiologic studies, require particularly fast, reproducible and, if possible, miniaturized protocols. Therefore, accurate and robust analytical methods are still needed to quantify the PFAS's burden in humans and to understand potential health risks. In this study, we have developed and validated the analysis of 42 PFAS in human plasma by means of a Captiva 96-well micro extraction plate and a LC-q-Orbitrap. For the optimization of the analytical workflow, three extraction/clean-up methods were tested, and the selected one was validated using spiked artificial and bovine plasma at four concentration levels. The final method showed high absolute recoveries for the 42 PFAS, ranging from 52% to 130%, instrumental detection limits between 0.001-0.6 ng mL^-1, overall good precision (CV < 20% for most of the PFAS) and a low uncertainty (< 30% of relative expanded deviation, k = 2). The method was further validated both with the NIST plasma Standard Reference Material 1950, showing that the accuracy of the provided results was between 63%-101%, and by the proficiency test arranged by the Arctic Monitoring Assessment Program (AMAP, 2022) obtaining satisfactory results within 95% confidence interval of the assigned value.