Silica-coated magnetic iron oxide functionalized with hydrophobic polymeric ionic liquid: a promising nanoscale sorbent for simultaneous extraction of antidiabetic drugs from human plasma prior to their quantitation by HPLC

Herein, silica-coated iron oxide nanoparticles modified with imidazolium-based polymeric ionic liquid (Fe3O4@SiO2@PIL) were fabricated as a sustainable sorbent for magnetic solid-phase extraction (MSPE) and simultaneous determination of trace antidiabetic drugs in human plasma by high-performance liquid chromatography-ultraviolet detection (HPLC-UV). The Fe3O4 core was functionalized by silica (SiO2) and vinyl layers where the ionic liquid 1-vinyl-3-octylimidazolium bromide (VOIM-Br) was attached through a free radical copolymerization process. In order to achieve hydrophobic magnetic nanoparticles and increase the merits of the sorbent, Br- anions were synthetically replaced with PF6-. The properties and morphology of the sorbent were characterized by various techniques and all the results illustrated the prosperous synthesis of Fe3O4@SiO2@PIL. A comprehensive study was carried out to investigate and optimize various parameters affecting the extraction efficiency. The limit of detection (LOD, S/N = 3) for empagliflozin, metformin and canagliflozin was 1.3, 6.0 and 0.8 ng mL(-1), respectively. Linearity (0.997 r(2) 0.993) and linear concentration ranges of 5.0-1200.0, 20.0-1800.0 and 5.0-1000.0 ng mL(-1) were obtained for empagliflozin, metformin and canagliflozin, respectively. Intra-assay (3.8-7.5%, n = 9) and inter-assay (3.2-8.5%, n = 12) precisions as well as accuracies (9.1%) displayed good efficiency of the method. Finally, the method was applied for the quantitation of antidiabetic drugs in human plasma after oral administration and main pharmacokinetic data including T-max (h), C-max (ng mL(-1)), AUC(0-24) (ng h mL(-1)), AUC(0-) (ng h mL(-1)), and T-1/2 (h) were evaluated.