Capillary electrochromatography (CEC) is a relatively new analytical separation technique, which is considered a hybrid between capillary electrophoresis (CE) and highperformance liquid chromatography (HPLC). This combination allows the use of an electrically driven flow to transport solvent and solutes through a chromatographic column, making use of a pluglike flow profile to provide high efficiency, with the possibility of retaining a variety of retention mechanisms and selectivity afforded by HPLC. CEC is capable of separating neutral solutes by differential interactions between the mobile and stationary phases. Additionally, separation of charged species is influenced by differential electromigration. Interest in CEC has been stimulated by the possibility of increasing the limited peak capacity of traditional liquid chromatography. The fundamental aspects of CEC have been discussed in a recent publication of this series , as well as others [2-5].