Separation and determination of the active ingredients in tablets of composite sulphonamides by capillary zone electrophoresis with amperometric detection Original Research Article

A simple, reliable and reproducible method, based on capillary electrophoresis with amperometric detection, for separation and determination of the active ingredients in tablets of the composite sulphonamides is described in this paper. A carbon-disc electrode used as working electrode for three analytes exhibits good responses at +1275 mV (vs. Ag/AgCl). Under the optimum conditions, three analytes were base-line separated, and excellent linearity was obtained in the concentration range from 3.0×10−6 to 5.0×10−4 mol/l. The detection limit was 1.0×10−6, 1.0×10−6, and 8.0×10−7 mol/l for sulphadiazine, sulphamethazine and trimethoprim, respectively. This method was successfully used in the analysis of actual pharmaceutical samples, and the assay results were satisfactory.