Boron-doped diamond electrode: a modification-free platform for sensitive square-wave voltammetric determination of indapamide hydrochloride

A boron-doped diamond electrode (BDDE) was employed for indapamide hydrochloride (IND) determination. IND presented an irreversible and diffusion-controlled oxidation peak at 0.53 V in 0.01 mol L-1 H2SO4 by cyclic voltammetry. To develop the voltammetric method, the effect of electrochemical pretreatment of BDDE, pH of supporting electrolyte, type of electrolyte and its concentration were evaluated. Under optimized instrumental parameters of square-wave voltammetry, the IND current was linear over the concentration range of 0.099-4.3 mol L-1, with limit of detection of 56 nmol L-1. The method was successfully applied to commercial tablets, and the obtained results were statistically similar to those obtained by a spectrophotometric method. Additionally, the determination of IND was accomplished in synthetic cerebrospinal fluid and tap water. The method proved to not suffer from matrix interference with excellent recoveries.