SEPARATION OF SOME PHARMACEUTICAL ADDITIVES BY MICROCHIP AND CAPILLARY ELECTROPHORESIS

Various pharmaceutical additives, erythrosine, methylparaben and propylparaben, were separated by capillary zone electrophoresis (CZE) in pharmaceutical preparations. Separations were carried out on electrophoretic microchip with conductivity detection and on electrophoretic analyzer with UV detection at 254 nm wavelength. Optimal pH of the background electrolyte was 9.75. Microchip with injected volume of a 900 nL has enabled the concentration limit of detection (cLOD) in the range 0.35-6.79 mu mol L-1 for studied analytes. Using conventional capillary electrophoretic instrument cLOD values were in the range 0.11-0.38 mu mol L-1. Both methods allow fast and reproducible determinations of erythrosine, methyl- and propylparabens in various pharmaceutical products (Gastrotuss, Paxeladine and Brufen).