Fast separations of chiral β-blockers on a cellulose tris(3,5-dimethylphenylcarbamate)-coated zirconia monolithic column by capillary electrochromatography.

Cellulose tris(3,5-dimethylphenylcarbamate) (CDMPC) is an excellent chiral selector for enantioseparation of a wide variety of chiral compounds. The monolithic chiral columns are becoming popular in liquid chromatography and capillary electrochromatography. In this work, we present the fast separation of chiral β-blockers on a CDMPC-modified zirconia monolithic column by capillary electrochromatography (CEC). The porous zirconia monolithic capillary column was prepared by using the sol-gel technology and then zirconia surface modified with CDMPC. The enantioseparations were performed in reversed-phase (RP) eluents of a phosphate solution (pH 4.4) modified with acetonitrile or alcohol. The enantioseparations of a set of eight chiral β-blockers were achieved in less than one minute. Influences of the applied voltage, column temperature, concentration of acetonitrile and the type of alcohol as the organic modifier in the mobile phase, and sample injection time on enantioseparation were investigated. CEC separations at the applied voltage of 10 kV and 15 °C in the ACN-modified mobile phase provided the best resolutions for the analytes studied. Run-to-run and day-to-day repeatabilities of the column in the RP-CEC separation were less than 1 and 2%, respectively.