How To Achieve Successful Chiral Separation by Capillary Electrophoresis

Abstract

This work is devoted to enhancing the potential of capillary electrophoresis as a separation technique. Improvement of chiral resolution of organic bases in an acid electrolyte using sulfated -cyclodextrin as an anionic chiral selector with respect to cationic analytes is demonstrated on an example of chiral separation of tamsulosin and ephedrine. Better resolution of enantiomers of the bases can be achieved by changing the concentration of a chiral selector in compartments of the separation system (inlet - capillary - outlet). Migration of the chiral selector in the direction opposite to that of the analyte was utilized and thus the resolution could be improved. The best resolution was obtained if the chiral selector was in the working electrolyte in the capillary and outlet vial while the inlet vial contained only the background electrolyte. In contrast, if the chiral selector is either only in the capillary or in the whole electrophoresis system, a lower resolution was obtained though both the systems are most frequently employed in practice.