Square-Wave Cathodic Adsorptive Stripping Voltammetric Determination of Trace Amounts of 2-Mercaptobenzimidazole in Water Samples

A sensitive, simple and reproducible square-wave cathodic adsorptive stripping voltammetric method is developed for the determination of 2-mercaptobenzimidazole (MBIM) in different water samples using a static mercury drop electrode (SMDE) as a working electrode. The solution conditions and instrumental parameters were optimized for the determination of MBIM by square-wave cathodic adsorptive stripping voltammetry. This method is based on a sensitive adsorptive reduction peak of the MBIM at -0.532 V vs. Ag/AgCl reference electrode in a Britton-Robinson buffer at pH 10.0. The linear concentration range was 20-600 ng ml-1 when using 0.0 V as the accumulation potential. The detection limit of the method was calculated to be 8.41 ng ml-1. The precision was excellent with relative standard deviations (n = 20) of 2.30%, 1.71%, 2.25% and 1.33% at MBIM concentrations of 40, 90, 200 and 500 ng ml-1, respectively. The proposed voltammetric method is used for the determination of MBIM in different spiked water samples