A novel electrochemiluminescence sensor coupled with capillary electrophoresis for simultaneous determination of quinapril hydrochloride and its metabolite quinaprilat hydrochloride in human plasma.

A novel electrochemiluminescence (ECL) sensor with composite consisted of silica-sol, Zinc oxide nanoparticles (ZnO NPs), polyvinylpyrrolidone (PVP) and tris(2, 2'-bipyridine) ruthenium (II) was constructed. A new method for simultaneous determination of quinapril hydrochloride (QHCl) and its metabolite quinaprilat hydrochloride (QTHCl) in human plasma was developed using the ECL sensor coupled with capillary electrophoresis (CE). ECL intensities of QHCl and QTHCl increased dramatically when the ECL sensor was used as working electrode. The running buffer contains 14mmol/L phosphate (pH 8.0) and 20% n-propyl alcohol. Under optimized experimental conditions, the linearity ranges of the method are 0.007-8.0μg/mL for QHCl and 0.009-8.3μg/mL for QTHCl. The detection limits of QHCl and QTHCl (S/N=3) are 3.6ng/mL and 3.9ng/mL, respectively. The method was applied for the simultaneous determination of QHCl and QTHCl in human plasma with satisfactory results.