DETERMINATION OF STRUCTURALLY RELATED PHENOTHIAZINES BY CAPILLARY ZONE ELECTROPHORESIS AND MICELLAR ELECTROKINETIC CHROMATOGRAPHY

Fourteen structurally related basic phenothiazines were determined by capillary zone electrophoresis (CZE) and micellar electrokinetic chrom atography (MEKC), applying electrolyte systems containing the fluorina ted cationic surfactant FC 135. Effective mobilities of the phenothiaz ines were determined as a function of pH by CZE in the anionic mode wi th a reversed electroosmotic flow (EOF). Larger differences in overall effective mobilities were obtained in MEKC, applying the cationic sur factant cetyltrimethylammonium bromide as micelle forming agent. The q uantitative abilities and matrix effects of CZE with reversed EOF were studied, and as an example the concentrations of thioridazine and pro methazine in pharmaceutical preparations were determined.