| 초록 |
Enantioseparation conditions and chiral recognition mechanism of ligand exchange chromatography were investigated using ofloxacin enantiomers. Chiral separation was performed on a C18 column, where the mobile phase consisted of a methanol-water solution (containing different concentrations of L-phenylalanine and copper sulphate) and its flow rate was set at 0.7 mL/min. The effect of different kinds and concentration of ligands, bivalent copper ion, organic modifier, ionic liquid modifier, pH of mobile phase, and temperature on enantioseparation were evaluated and the results show that the enantioselectivity was strongly affected by the pH and ligands concentration of the mobile phase. Under the optimum condition, baseline separation of the two enantiomers was obtained with a resolution of 4.69 in less than 40 min. The mechanism of chiral discrimination is based on the stabilities of the copper(II) binary complexes and their ternary diasteremeric complexes with amino acids formed in solution and stationary phase. The proposed method could be used for the quality evaluation of ofloxacin enantiomers. |
