Voltammetric behavior of chlorhexidine at a film mercury electrodes and its determination in cosmetics and oral hygiene products

The voltammetric behaviors of chlorhexidine on glassy carbon and electrodeposited mercury electrodes were investigated in an aqueous medium containing various supporting electrolyte. The various factors such as deposition material, time, concentration of mercury(II) and of coexisting inorganic, organic and surfactant interferences on the precision of the analysis have been explored. The possible reaction mechanisms were discussed by the relations of scan rate and peak potentials and currents. A comparison is made between the detection limit of glassy carbon, thin-film modified on glassy carbon and gold electrode. The electroreduction process is applied for the simultaneous quantitative determination of antiplaque agent and anticaries in oral hygiene products. The antiplaque agent (chlorhexidine) and anticaries (aluminum fluoride and sodium fluoride) of toothpaste in 1+1 mixture of 0.1 M lithium chloride and lithium hydroxide have a stripping peak at -1.88, -1.69 and -1.30 V for chlorhexidine, aluminum fluoride and sodium fluoride, respectively. Comparison with results obtained from highperformance liquid chromatography shows 98% good agreement.