Monolithic stationary phases for enantioselective capillary electrochromatography

Monolithic capillary electrochromatography (CEC) columns containing polymerized quinidine carbamate units have been prepared and used for enantioselective separations of modified amino acids. Optimization of both monolithic structure and mobile phase variables such as the ionic strength, type, and composition of eluent affords enantioselective CEC separations characterized by both high resolution and efficiency. For example, an efficiency of up to 250,000 plates/m was achieved for the separation of 2,4-dinitrophenyl-derivatized amino acids. The simple preparation together with the large variability of readily available chemistries make the monolithic separation media an attractive alternative to capillary columns packed with beads.