A microsampling approach for the determination of 13 per- and polyfluoroalkyl substances in capillary dried plasma

Per- and polyfluoroalkyl substances (PFAS) are widely used in consumer products and are associated with adverse health effects. Although PFAS are commonly measured in venous plasma, dried plasma spots (DPS) obtained from capillary blood have emerged as an alternative for biomonitoring studies, particularly in developing countries. This study validated an LC-MS/MS method for the determination of 13 PFAS in DPS. Four drops of capillary blood collected by fingerprick were applied to Health ID PSD devices. DPS were extracted with an aqueous buffer, followed by protein precipitation with acetonitrile and solid-phase extraction.

Analytes remained stable in DPS for up to 21 days. Chloride-corrected DPS concentrations, after using a multiplication factor, predicted plasma levels with strong correlation (r = 0.959), without proportional or systematic bias and with acceptable precision. PFOS was the only compound detected at concentrations ≥0.5 ng/mL (LLOQ) in all samples, with predicted plasma concentrations of 0.84–18.3 ng/mL. The method demonstrated good performance for biomonitoring studies.