COMPARATIVE-STUDY OF CAPILLARY ZONE ELECTROPHORESIS AND MICELLAR ELECTROKINETIC CHROMATOGRAPHY FOR THE SEPARATION OF 12 AROMATIC SULFONATE COMPOUNDS

Two modes of capillary electrophoresis (CE), capillary zone electropho resis (CZE) and micellar electrokinetic chromatography (MEKC), were in vestigated for the separation of 12 aromatic sulphonate compounds. In CZE, although the voltage applied, the buffer concentration and the pH were optimized for effective separation of the compounds studied, und er the best conditions four of the five amino compounds coeluted, as d id naphthalene-1-sulphonic acid and naphthalene-2-sulphonic acid. In M EKC, sodium dodecyl sulphate (SDS) and Brij 35 were chosen as the anio nic and nonionic surfactants and the effect of the concentration of mi celles was examined. The effect of adding methanol as the organic modi fier was also investigated with each of these micellar systems. All th e analytes, including the isomers, were completely separated by use of MEKC with Brij 35 but when SDS was used only 11 compounds were separa ted because two amino compounds coeluted.