Chiral separations by capillary electrophoresis: present state of the art

Capillary electrophoresis is a powerful tool for chiral separation of ionogenic enantiomers in solutions. This article brings an overview of the theory of electrophoretic separations with special emphasis on enantiomer-chiral selector equilibria, followed by a survey of indirect separations, based on formation of diastereomers with different electrophoretic mobilities, and a comprehensive appraisal of direct separations when the chiral recognition stems from (i) host-guest interactions using cyclodextrins and crown ethers as hosting agents, (ii) ligand exchange mechanism, (iii) affinity interactions or (iv) a combination of solute-chiral selector interactions with micellar electrophoretic transport. Finally, some trends in chiral separations by capillary electrophoresis are discussed.