Enantioseparation of 2-chloromandelic Acid Enantiomers by Ligand Exchange Chromatography Based on Chiral Ionic Liquids

Enantioseparation of 2-chloromandelic acid enantiomers by ligand exchange chromatography was successfully carried out using chiral ionic liquids (CILs) containing imidazolium cation and L-Proline anion as chiral selectors. The main factors influencing resolution, such as alkyl chain length of CILs, concentrations of Cu2+ and CILs, pH of the mobile phase and temperature, were investigated. To better understand the enantioseparation process, some thermodynamical parameters were evaluated, and the results indicated that the chiral separation of 2-chloromandelic acid enantiomers was an enthalpy-controlled process.