Enantiomer separations of basic chiral compounds by capillary electrochromatography on a phosphated β-cyclodextrin-modified zirconia monolith

Phosphated β-cyclodextrin (PCD)-coated zirconia monolith was used as the chiral stationary phase in capillary electrochromatography (CEC) for separation of four basic chiral compounds including metoprolol (MET), sertraline (SER), citalopram (CIT) and atenolol (ATE). Migration, chiral selectivity and resolution data were measured in reversed-phase mobile phases of varying pH, buffer and organic modifier compositions. Optimum mobile phase conditions for CEC separation of the compounds studied were found to be a 15-mM aqueous buffer of pH 5.0 with 5 mM PCD. Baseline separations of enantiomers of CIT, MET and SER, and partial separation for ATE were achieved with the optimal mobile phase.