Effective determination of trace residues of glibenclamide in urine samples using dispersive micro solid-phase extraction and its final detection by chromatographic analysis†
An analytical procedure for rapid and effective dispersive micro-solid-phase extraction (DMSPE) of glibenclamide (GB) from urine samples was set up by using sulfur doped tin oxide nanoparticles (S@SnO2-NPs) loaded on activated carbon (AC), as the sorbent, and clean-up materials, followed by detection. The main experimental parameters affecting the extraction efficiency for GB were assessed and optimized. The maximum recovery of GB predicted by optimization plots was 98.86%, obtained with 15 mL of water, 250 μL of methanol (as an eluent), pH 8.0, 25 mg of S@SnO2-NPs-AC, and an extraction time of 2.5 min. Our results indicated that under these optimized extraction conditions, determination coefficients (R2) of the calibration curves in the range of 0.60–5500 μg L−1 were >0.991, detection limits (signal-to-noise ratio = 3) were in the range of 0.09–0.16 μg L−1, the average recoveries of spiked GB in urine samples were 95.73–105.50%, and assessed relative standard deviations (RSDs, %) were between 1.15 and 6.84%. The results also demonstrated that the presented method could be suitable for the determination of trace residues of GB in urine samples.