The Performance of Boron-Doped Diamond Electrode for the Determination of Ramipril and its Association with Hydrochlorothiazide

The voltammetric behavior of ramipril (RMP), an angiotensin-converting enzyme inhibitor, was investigated for the first time in the literature on a boron-doped diamond electrode (BDDE) using cyclic (CV) and square-wave voltammetry (SWV). Its behavior was also considered in the presence of a thiazide diuretic, hydrochlorothiazide (HCTZ), for the simultaneous determination. The performance of BDDE and glassy carbon electrode (GCE) was compared, since RMP provides a high oxidation potential. It was observed that the anodic peak potentials for HCTZ and RMP at the BDDE were 1.23 and 1.67 V (vs. Ag/AgCl (3.0 mol L-1 KCl)) by CV in BR buffer solution (pH 2.0), respectively. The influence of supporting electrolyte, pH and scan rate in the current response of these both drugs was examined to select optimum experimental conditions. By this way, the determination of RMP and its association with HCTZ using SWV and a BDDE was successfully applied in real samples (single and combined dosage forms), with results in close agreement at 95% confidence level with those obtained using high-performance liquid chromatography.