单分散树脂键合手性配体交换色谱固定相拆分DL-氨基酸

以单分散交联聚甲基丙烯酸环氧丙酯-甲基丙烯酸乙二醇双酯(PGMA/EDMA)树脂为基质合成了L-脯氨酸键合手性配体交换固定相,并用于DL-氨基酸的直接光学拆分,考察了流动相pH值、金属离子浓度、流速及温度等因素对DL-氨基酸对映体拆分的影响。结果表明,该固定相在配体交换色谱模式下可对多对DL-氨基酸进行良好的拆分。

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.