[Separation of enantiomers of three chiral drugs by capillary electrophoresis based on achiral ionic liquid].

Using an achiral ionic liquid, 1-butyl-3-methylimidazolium chlorine ([ BMIM] Cl), as an additive and beta-cyclodextrin (beta-CD) as a chiral selector, the enantiomers of chlorpheniramine, the precursor of chloramphenicol and of loxacin were separated by capillary zone electrophoresis. This work was directed to the study of the association of [BMIM] Cl to the chiral selector beta-CD and the possible effects of [BMIM] Cl on chiral separation. Simultaneously, the separation performances were studied when only containing beta-CD in the buffer. The results showed that there are synergistic effects of [BMIM] Cl as an additive for the enantiomeric separations. [BMIM] Cl can not only remarkably increase the separation selectivity and resolution of the enantiomers, but also effectively restrain the adsorption of the sample molecules and improve the peak shape. [BMIM] Cl as an additive of chiral separation can provide a new method for the separation of chiral drugs which are hard separable under common electrophoresis conditions.