Electrochemical oxidation of chlorhexidine and its amperometric determination by flow-injection analysis

The electrochemical oxidation of chlorhexidine is investigated for the first time and its amperometric determination using a flow-injection analysis (FIA) system is demonstrated. An oxidation peak was observed at around 1.3 V in a 0.1 mol L-1 HClO4 solution at a glassy-carbon electrode. The mechanism of the electrochemical oxidation of chlorhexidine is pH-dependent and involves a single-electron transfer possibly via radical cation formation. The FIA parameters were optimized and a detection limit of 0.3 mu mol L-1 was obtained. The proposed method was applied in mouth rinses and skin disinfectants samples and compared with high-performance liquid chromatography.