Flow Injection Chemiluminescence Determination of Captopril with In Situ Electrogenerated Mn3+ as the Oxidant

Abstract

By designing a novel flow-through electrolytic cell, a new flow-injection electrogenerated chemiluminescence method for the determination of captopril is described. It is based on the direct chemiluminescence oxidation of captopril by nascent Mn3+ which was in situ electrogenerated on the near surface of the platinum flake electrode by electrochemical oxidizing MnSO4 in sulfuric acid medium. The proposed procedure has a linear application range of 3.0×10−7–1.0×10−4 mol/L for captopril (r=0.9998) and with a detection limit of 8.0×10−8 mol/L original concentration. Designing of the flow-through electrolytic cell as well as some experimental conditions for the determination of captopril are optimized and the possible reaction mechanism is also discussed. The method was successfully used for the determination of captopril in a pharmaceutical preparation.