Mirror-Image β-l-Cyclodextrin as a Chiral Pseudophase in Capillary Electrophoresis

Cyclodextrins (CDs) and their derivatives are among the most versatile and effective pseudophases used for chiral capillary electrophoresis (CE). They provide a variety of interactions that could be further expanded by derivatization. Among the three native CDs used in CE, $\beta$ -d-CD and its derivatives have been the most effective chiral selectors and have shown enantioselectivity for a variety of pharmaceutical analytes. The advent of mirror-image CDs has provided great potential in chiral CE applications. In this study, the chiral separation of 38 analytes was investigated with capillary electrophoresis and the enantiomeric selectivity was compared utilizing $\beta$ -d-CD and $\beta$ -l-CD as CE pseudophases. Additionally, the parameters affecting the CE separation, including pH of the run buffer, capillary voltage, and ionic strength of the buffer, were examined. For the first time, the opposite enantioselectivity of the $\beta$ -l-CD was utilized to facilitate challenges in the quantitation of chiral impurities in pharmaceutical compounds.