手性离子液体配体交换色谱拆分扁桃酸对映体的研究

Chiral Separation of Mandelic Acid Enantiomers by Ligand Exchange Chromatography Based on Chiral Ionic Liquids

本文基于配体交换的机理,研究了以脯氨酸手性离子液体作为手性配体拆分扁桃酸(MA)对映体的方法及热力学过程。详细考察了手性离子液体的烷基链长、铜离子的浓度、离子液体的浓度和pH等因素对MA对映体分离的影响。研究发现,不同烷基链长的手性离子液体中,以1-丁基-3-甲基咪唑L-脯氨酸为配体时,MA对映体的拆分效果最好;随着铜离子浓度的增加,MA对映体的保留时间和分离度先增大再减小;而随着1-丁基-3-甲基咪唑L-脯氨酸离子液体的浓度和流动相pH的增大,保留时间和分离度均增大。本文还测定了拆分过程中的一些热力学参数,结果表明,MA对映体的拆分过程是一个焓控的过程,L-MA较D-MA与固定相有更强的相互作用,保留时间更长。

Resolution of mandelic acid enantiomers by ligand exchange chromatography with the chiral ionic liquids（ILs） containing imidazolium cations and L-proline anions as chiral selectors and its thermodynamical process were studied.Some resolution influencing factors,such as alkyl chain length of ILs,concentrations of Cu2＋ and ILs,and pH of the mobile phase,were investigated.When the alkyl chain length is C4,the chiral ionic liquid has the best enantioselectivity.The values of t and R both increase before the concentration of Cu2＋ is up to 8mmol/L and then decline when the concentration of Cu2＋ further increases.And these values also increase with the increase of concentrations of ILs and pH of the mobile phase.Some thermodynamical parameters were evaluated,which showed that the chiral separation of mandelic acid enantiomers is an enthalpy-controlled processs and that L-MA has stronger affnity to the stationary phase.