ABSTRACT
I. INTRODUCTION Micellar electrokinetic chromatography (MEKC) is a separation technique in which the basic properties of micellar liquid chromatography and capillary electrophoresis are combined. It was first described by Terabe et al. (1) in 1984 for the separation of nonionic aromatic compounds and is a powerful separation technique for lipophilic and nonionic species. By addition of SUffactants to the background electrolyte, new options for solving electrophoretic separation problems are opened, but it is also possible to apply this technique to the study of affinities of drugs and other molecules of interest to surface-active compounds. The term micellar affinity capillary electrophoresis (MACE) is used to describe the study of such interactions employing the same phenomena as present in MEKC. Of main interest is not the achievement of good separation or high detection sensitivity but the study of the effect of the type of micelle-forming compounds and its concentration [above the critical micelle concentration (CMC)] on the mobility of the solutes/drug. This is affected by the affinity of the solute to the micelle. Although MACE and ACE (affinity to nonmicellar buffer additives) are based upon the same principle, in the recent literature both methods are discussed separately.
