L-异亮氨酸型配体交换固定相对DL-氨基酸的拆分研究

用自制的新型L-异亮氨酸配体交换固定相在配体交换模式下对11种DL-氨基酸进行了拆分研究,详细考察了流动相中铜离子浓度、甲醇含量、流速及温度对拆分效果的影响,并探讨了可能的拆分机理。研究结果表明:流动相中高浓度的铜离子不利于DL-氨基酸的拆分;增加流动相中甲醇的含量,降低流动相流速以及提高色谱柱温度均可改善拆分效果。

Study of Enantiomeric Separation of DL-Amino Acids on L-Isoleucine-Type Chiral-Ligand-Exchange Stationary Phase

Some underivatized DL-amino acid enantiomers were separated on L-isoleucine-type chiral-ligand-exchange stationary phase (EILE). The effects of contents of copper ion and methanol in mobile phase, temperature of column and flow rate of eluent on the efficiency and resolution of DL-amino acids were investigated in detail. The results showed that Cu(II) ion played an important role in the separation. When there was no Cu(II) ion in mobile phase, the DL-amino acids could not be enantio-separated, while the content of Cu(II) increased from 0.3 mmol/L to 1.2 mmol/L, the efficiency of resolution and retention time decreased. The increases of the content of methanol and column temperature are in favor of the resolution for most of DL-amino acids. The flow rate also affected the resolution results. Good results could be obtained in reducing flow rate but it prolongs the retention time. The mechanisms of different chiral separation results on the new stationary phase under different conditions were also investigated.