An antibiotic drug, D-cycloserine (CYS), in phosphate buffer at different pH values was electrochemically studied using a gold electrode. A well-resolved, irreversible, diffusion-controlled voltammetric peak was obtained at 0.873 V in a pH 9.2 phosphate buffer solution with an ionic strength of 0.2 M. The experimental conditions, such as the solution pH and scan rate, were optimized. The pH dependence suggested that equal numbers of protons and electrons were involved in the electrochemical oxidation of CYS. A plausible oxidation mechanism was proposed. Under the selected conditions, the dependence on the concentration of CYS revealed that the detection limit for CYS was 3.3 × 10−8 M for differential pulse voltammetry and 4.91 × 10−8 M for square wave voltammetry. The proposed method was successfully applied to the determination of CYS in drug capsules and urine samples. The electrode exhibits good reproducibility and stability. In addition, the influence of various foreign species was studied.
D-Cycloserine; Electrooxidation; Voltammetry; Analytical applications
Citation: Vijay P. Pattar, Sharanappa T. Nandibewoor Electrochemical studies for the determination of an antibiotic drug, D-cycloserine, in pharmaceutical and human biological samples doi:10.1016/j.jtusci.2015.05.003
Available online 17 June 2015
Copyright: © 2015 The Authors. Production and hosting by Elsevier B.V. on behalf of Taibah University. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).
The voltammetric behaviour of CYS at a GE in a phosphate buffer solution (pH 9.2) was investigated. CYS undergoes a two-proton two-electron change through a diffusion-controlled process. A suitable mechanism was proposed. The peak current was linear with CYS concentration over a certain range, under optimized conditions, and DPV had a better detection limit of 3.3 × 10−8 M. The proposed method was successfully applied to capsule and urine samples. The recoveries obtained for pharmaceutical formulations and urine samples show the applicability of these techniques to control analysis for these drugs.