Novel bovine serum album and β-cyclodextrin-based mixed chiral stationary phase for the enantioseparation in capillary electrochromatography

A capillary was co-immobilized with mixed β-cyclodextrin and bovine serum album by chemical covalent coupling as the chiral stationary phase for the enantioseparation of proton-pump inhibitors in capillary electrochromatography. The chromatographic parameters including buffer concentration, pH value, organic modifier, and applied voltage were optimized. The separation performance of the developed column was evaluated by enantioseparating omeprazole, lansoprazole, pantoprazole, and esomeprazole with extremely high resolutions of 5.21, 7.11, 6.39, and 4.75, respectively. Moreover, the mixed chiral stationary phase exhibited a broader range and could separate more than 10 chiral analytes compared to the single-selector column. The relative standard deviations of the day-to-day and column-to-column repeatability were less than 4%, demonstrating excellent stability of the fabricated column. An open tubular capillary immobilized with the bovine serum album and β-cyclodextrin as the chiral stationary phase is a promising prospect for separating chiral drugs in capillary electrochromatography because of the combination of the enantioselectivities of both individual selectors.