title: Automated determination of total captopril in urine by liquid chromatography with post-column derivatization coupled to on-line solid phase extraction in a sequential injection manifold.
abstract: The present study reports a new liquid chromatographic (HPLC) method for the determination of the anti-hypertension drug captopril (CAP) in human urine. After its separation from the sample matrix in a reversed phase HPLC column, CAP reacts with the thiol-selective reagent ethyl-propiolate (EP) in a post-column configuration and the formed thioacrylate derivative is detected at 285 nm. Automated 4-fold preconcentration of the analyte prior to analysis was achieved by an on-line solid phase extraction (SPE) step using a sequential injection (SI) manifold. The Oasis HLB SPE cartridges offered quantitative recoveries and effective sample cleaning by applying a simple SPE protocol. The limits of detection and quantitation were 10 μg L(-1) and 35 μg L(-1) respectively. The percent recoveries for the analysis of human urine samples ranged between 90 and 96% and 95 and 104% using aqueous and matrix matched calibration curves respectively.
authors.affiliation: Laboratory of Analytical Chemistry, Department of Chemistry, Aristotelian University of Thessaloniki, GR-54124 Thessaloniki, Greece.
authors.forename: Theano D
authors.initials: TD
authors.lastname: Karakosta
authors.forename: Paraskevas D
authors.initials: PD
authors.lastname: Tzanavaras
authors.forename: Demetrius G
authors.initials: DG
authors.lastname: Themelis
mesh_terms: D000179:Acrylates / Q000032:analysis*; D000480:Alkynes / Q000737:chemistry; D000959:Antihypertensive Agents / Q000652:urine*; D057205:Automation, Laboratory; D002138:Calibration; D002216:Captopril / Q000652:urine*; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D017022:Flow Injection Analysis; D006801:Humans; D011422:Propionates / Q000737:chemistry; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D052616:Solid Phase Extraction
chemical_list: D000179:Acrylates; D000480:Alkynes; D000959:Antihypertensive Agents; D011422:Propionates; D002216:Captopril; C544697:ethyl propiolate