title: Determination of the angiotensin-converting enzyme inhibitor quinapril and its metabolite quinaprilat in pharmaceuticals and urine by capillary zone electrophoresis and solid-phase extraction.
abstract: Quinapril is an antihypertensive drug commonly used in the treatment of hypertension and congestive heart failure. In this work, a capillary zone electrophoresis system is optimized for the analysis of quinapril and its active metabolite quinaprilat in urine, as well as for the determination of the drug and its combination with hydrochlorothiazide in pharmaceuticals. The separation takes place in a fused-silica capillary. The running electrolyte consists of a 60 mM borate buffer solution, pH 9.5. The analysis of urine samples requires a previous extraction step using C8 solid-phase cartridges. Under the optimum experimental conditions, the separation of the two analytes and the internal standard takes less than 5 min. The detection limits obtained (75 and 95 ng/mL for quinapril and quinaprilat, respectively) allow the application of the electrophoretic method to the determination of the drug and its metabolite in urine samples obtained from four patients treated with quinapril.
authors.affiliation: Departamento de Química Analítica, Facultad de Ciencias, Universidad del País, Vasco UPV/EHU, Bilbao, Spain.
authors.forename: José Angel
authors.initials: JA
authors.lastname: Prieto
authors.forename: Rosa María
authors.initials: RM
authors.lastname: Alonso
authors.forename: Rosa María
authors.initials: RM
authors.lastname: Jiménez
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000806:Angiotensin-Converting Enzyme Inhibitors / Q000032:analysis* / Q000652:urine; D002138:Calibration; D019075:Electrophoresis, Capillary / Q000295:instrumentation / Q000379:methods* / Q000592:standards; D005260:Female; D006801:Humans; D007546:Isoquinolines / Q000032:analysis* / Q000652:urine; D008297:Male; D008875:Middle Aged; D004364:Pharmaceutical Preparations / Q000032:analysis; D000077583:Quinapril; D012015:Reference Standards; D012680:Sensitivity and Specificity; D044005:Tetrahydroisoquinolines
chemical_list: D000806:Angiotensin-Converting Enzyme Inhibitors; D007546:Isoquinolines; D004364:Pharmaceutical Preparations; D044005:Tetrahydroisoquinolines; C054501:quinaprilat; D000077583:Quinapril