Electroanalytical study of succinylsulfathiazole and phtalylsulfathiazole at a glassy carbon electrode

Abstract

An electroanalytical study of succinylsulfathiazole and phtalylsulfathiazole oxidation processes at a glassy carbon electrode using different voltammetric techniques was carried out. Results obtained at a rotating disk electrode allow the determination of the pK, values of the reduced and oxidized forms. Limiting currents are diffusion controlled in concentration ranges of 1.0 X mol L-' for succinylsulfathiazole and phtalylsulfathiazole, respectively. Adsorption phenomena occur at higher concentrations, becoming stronger as the acidity of the medium increases. From differential pulse voltammeuy at a stationary electrode, the limits of determination were 3.7 X and 4.7 x mol L-' for succinylsulfathiazole and phtalylsulfathiazole, respectively. Interferences between the two sulfa drugs were studied. The application of Merentid pulse voltammetry at a stationary electrode gave good results for the determination of phtalylsulfathiazole in a commercid pharmaceutical preparation. to 5.0 x and 2.0 X to 6.0 x