Solid-phase extraction and high-performance liquid chromatography applied to the determination of quinapril and its metabolite quinaprilat in urine.
Quinapril is an antihypertensive drug that belongs to the family of angiotensin-converting enzyme inhibitors. It is metabolized to quinaprilat, which is the compound that is really responsible for the therapeutic action. In this study, a rapid and simple liquid chromatographic method with photometric detection is described and applied to the determination of quinapril and quinaprilat in urine. The cleanup procedure for the urine samples consists of a solid-liquid extraction using C8 cartridges. Under these conditions, both compounds and the internal standard (enalapril maleate) are separated in less than 9 min. Recoveries for quinapril and quinaprilat are greater than 80%. The method is sensitive enough (detection limit of 60 ng/mL for quinapril and 50 ng/mL for quinaprilat) to be applied for the determination of quinapril and quinaprilat in urine samples obtained from four hypertensive patients after the intake of a therapeutic dose.
Prieto
J A
JA
Departamento de Química Analítica, Facultad de Ciencias, Universidad del País Vasco, Bilbao, Spain.
Alonso
R M
RM
Jiménez
R M
RM
Blanco
A
A
D000959:Antihypertensive Agents / Q000652:urine*; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D006801:Humans; D007546:Isoquinolines / Q000652:urine*; D000077583:Quinapril; D015203:Reproducibility of Results; D044005:Tetrahydroisoquinolines
D000959:Antihypertensive Agents; D007546:Isoquinolines; D044005:Tetrahydroisoquinolines; C054501:quinaprilat; D000077583:Quinapril