Evaluation of electrospun fibers as solid phase extraction sorbents for sample preparation in HPLC-MS/MS confirmatory doping control analysis of dexamethasone and betamethasone

Abstract

The aim of the present work was to evaluate the possibility of a fast, simple, and greener sample preparation method using electrospun fibers as SPE sorbents and its application for doping control analysis. Electrospun polymer fibers of polystyrene with smooth morphology (1.3 μm average diameter) were used as sorbent materials for the fabrication of miniaturized solid phase extraction devices. A microcolumn SPE device (10 mg of electrospun fibers packed in a 200 μL pipette tip) and a SPE disk device (10 mg of electrospun fibers packed in a 500 μL polypropylene barrel) were used. Their performance was evaluated using dexamethasone and betamethasone as model analytes for the analysis of drug residues in biological samples. A qualitative confirmatory method for the detection of these glucocorticosteroids by HPLC-MS/MS in human urine was developed using electrospun microfibers for sample clean-up and pre-concentration. The limit of detection for both analytes was 10 ng mL⁻¹ in urine matrix, and the resulting analytical method is at the same time fit for purpose (complying with strict requirements of doping control international organizations), simple (using tip-based microcolumns) and has a greener footprint (using very small amounts of organic solvents).