Voltammetry of benzodiazepines on meniscus-modified silver solid amalgam electrode

This paper describes voltammetric behavior of 1,4-benzodiazepines (BDZs) on meniscus-modified silver solid amalgam electrode with aim of their determination. Cyclic voltammetry was used for the study of electro- chemical behavior (reversibility, adsorption-diffusion process, and charge transfer coefficient) of BDZs. Differ- ential pulse voltammetry was utilized for proposing reaction mechanism, finding supporting electrolyte with optimal pH, and determining diazepam in urine. The pH effect was studied in different media (Britton-Robinson, phosphate, citrate buffer, and 0.1 mol dm -3 NaOH). The calibration dependences exhibited good linearity in the range from 10 -7 to 10 -4 mol dm -3 under the optimum pH conditions. The advantage of the developed methods was simple, fast, and low-cost procedure for the determination of BDZs. The developed method was successfully used for the diazepam determination in the model sample of urine. The proposed method exhibits the recovery 97.8 % with standard deviation of 2.28 %. Graphical abstract