Chapter 3 Electrokinetic chromatography

Abstract

Publisher Summary Capillary electrophoresis (CE) is a technique that was developed for the efficient separations of charged solutes, based on their differences in electrophoretic mobility. Micellar electrokinetic capillary chromatography (MECC), introduced in 1984, allows neutral species to be resolved using CE instrumentation by creating a second retentive phase into which they can differentially partition. The differential partitioning gives rise to differential migration rates that provide the separation. Micelles or other charged species added to a buffer solution impart an effective electrophoretic mobility to neutral analytes by interacting with the neutral compound to form a charged “complex.” The binding constants of the analytes can be measured in a variety of ways—that is, from absorbance or fluorescence measurements, by micellar liquid chromatography (MLC), and by micellar electrokinetic chromatography (MEKC). The separation of charged solutes by electrokinetic chromatography (EKC) involves a combination of chromatographic and electrophoretic separation mechanisms. This results in biases or differences in migration behavior for various types of analytes.