SEPARATION OF PHENYLENEDIAMINE, PHENOL AND AMINOPHENOL DERIVATIVES BYMICELLAR ELECTROKINETIC CHROMATOGRAPHY - COMPARISON OF THE ROLE OF ANIONIC AND CATIONIC SURFACTANTS

mixture of phenylenediamine, aminophenol and phenol derivatives was st udied with capillary zone electrophoresis (CZE) at different pi-Is. Th e use of acidic dr alkaline pH did not give separations with a good re solution. Next, separation was performed using micellar electrokinetic capillary chromatography (MEKC), first with the anionic surfactant so dium dodecyl sulfate (SDS) and second with the cationic surfactant cet yl trimethylammoniumchloride (CTACl). In both cases, a study of pH, su rfactant concentration and ionic strength of the electrolyte as functi on of the capacity factor allowed for the determination of the optimum conditions. Since separation was obtained with both surfactants, we s tudied the distribution coefficient to determine the affinities of the solutes for the aqueous medium and the different surfactants.