Micellar electrophoresis using ionic liquids

In this study, ionic liquid based cationic surfactants were evaluated as pseudo-stationary phases in micellar electrokinetic chromatography (MEKC). The aggregation behaviour of long-chain (C-12 and C-14) alkylimidazolium ionic liquids in water and aqueous phosphate buffer was investigated by spectrophotometry. The critical micelle concentrations of these salts were determined and compared to those of tetradecyl- and dodecyltrimethylammonium chloride, salts commonly used in capillary electrophoresis. The practical utilization of a new type of surfactant in MEKC was evaluated by introducing an ionic liquid into the running aqueous buffer to separate neutral analytes-methylresorcinol isomers and benzene derivatives. (C) 2008 Elsevier B.V. All rights reserved.