Electrophoresis · 2007 · 47 citations · 25 references
PharmacyPharmaceutical AnalysisAnalytical ChemistryAnalytical ToxicologyMass Spectrometric AnalysisAnalytical ChromatographyChromatographyInstrumental AnalysisLiquid ChromatographyMetabolite ExtractionElectrophoretic DetectionExtraction Of Organic CompoundsHollow Fiber MembranesInternal Standard AnalysisLiquid Chromatography-mass SpectrometryLiquid Chromatography-mass Spectrometry AnalysisMicroextractionToxicological Analysis Of Urine
Liquid-phase microextraction based on polypropylene hollow fibers and CE were applied for the chiral determination of hydroxychloroquine (HCQ) and its metabolites (desethylchloroquine, DCQ; desethylhydroxychloroquine, DHCQ; bisdesethylchloroquine, BDCQ) in human urine. The analytes were extracted from 3 mL of urine spiked with the internal standard (metoprolol) and alkalinized with 250 muL of 2 M NaOH. The analytes were extracted into 1-octanol impregnated in the pores of the hollow fiber, and into an acid acceptor solution inside the hollow fiber. The electrophoretic separations were carried out in 100 mmol/L Tris buffer (pH adjusted to 9.0 with phosphoric acid) containing 1% w/v S-beta-CD and 30 mg/mL HP-beta-CD with a constant voltage of +18 kV. The method was linear over the concentration range of 10-1000 ng/mL for each HCQ stereoisomer and 21-333 ng/mL for each metabolite stereoisomer. Within-day and between-day assay precision and accuracy for the analytes were studied at three concentration levels for each stereoisomer and were lower than 15%. The developed method was applied for the determination of the cumulative urinary excretion of HCQ, DCQ, and DHCQ after oral administration of rac-HCQ to a health volunteer. The results obtained are in agreement with previous literature data.
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Solvent Microextraction into a Single Drop
Michael A. Jeannot, Frederick F. Cantwell · Analytical Chemistry · 1996 · 1.3K citations
Knut Rasmussen, Stig Pedersen‐Bjergaard, Mette Krogh et al. · Journal of Chromatography A · 2000 · 298 citations