[Ligand exchange chromatographic separation of DL-amino acids based on monodisperse resin-bonded chiral stationary phase].

L-Proline chiral stationary phase for ligand exchange chromatography was prepared in the following steps. First, the particles were completely hydrolyzed. Second, the hydrolyzed particles reacted with epichlorhydrin to obtain chlorinated beads. Third, the chlorinated beads reacted with L-proline. The chiral stationary phase was characterized by elemental analysis. Chromatographic resolutions of DL-amino acids were achieved on the chiral stationary phases by using 0.1 mol/L NaAc with 0.1 mmol/L Cu(Ac)2 solution as mobile phase and detection at 254 nm. The elution order of D-isomer before L-isomer was observed for all the DL-amino acids resolved except DL-proline. For DL-proline the elution order was different from the others because of its five membered ring structure. The influences of the mobile phase pH, concentration of Cu(II), flow rate of eluent and temperature of column on the resolution of DL-amino acids by ligand exchange chromatography were investigated for the optimization of chromatographic conditions. The results showed that enantioseparation of some DL-amino acids was performed by ligand exchange chromatography on this chiral stationary phase with satisfactory results.