A Study of Chromatographic Resolution of Enantiomers: Solvent Characteristics of Supercritical Fluid and Liquefied Gas

对映体的色谱分离研究：超临界流体和液化气的溶剂特性

基本信息

批准号：
62550696
负责人：
NITTA Tomoshige
金额：
$ 1.22万
依托单位：
Osaka University
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (C)
财政年份：
1987
资助国家：
日本
起止时间：
1987 至 1988
项目状态：
已结题

项目摘要

The present work concerns with the separation characteristics of the supercritical carbon dioxide and liquified propane as a mobile phase in chromatographic resolution of potically active isomers. Two enantiomers, trans-stilbene oxide and 1-(9-anthryl)-2,2,2-trifluoroethanol, were resolved by a column with a chiralcellulose derivative coated on a silica gel. The experimental results are summarized as follows.(1) Carbon dioxide, propane and hexane are in the order of high resolution; the order is in parallel to the diffusivity in each solvent.(2) The capacity ratio decreases with increasing the concentration of alcohols for the three solvents. It also decreases with increasing pressure in case of the supercritical fluid. These observations may be explained by the competitive adsorptions of solute and solvent molecules on active sites.(3) The separation factor significantly increases with decreasing temperature, and it changes a little according to the combination of major fluids and add … More ed alcohols. The relative stability of adsorbed enantiomers may be controlled majorly by the solutes-polymer interactions and secondly by the solutes-solvents interactions in the adsorbed phase.(4) The separation factor of enantiomers increases slightly with increasing pressure of the supercritical fluid, which corresponds to the decrease of alcohol concentration in the adsorbed phase.(5) In a low velocity region where molecular diffusion and fluid-mixing are predominant, the overall mass transfer resistance for polymer-coated silica gel is smaller than that for the naked gel; however, in a high velocity region, the polymer-coated silica gel shows higher resistance than the naked. There may be two plausible explanations: 1) increase of the tortuosity factor in the porous particle due to the inclusion of polymers 2) particle coalescence due to the polymers attached on the outside of particles. The fundamental research on polymer coating method will be necessary for improving column efficiency. Less

目前的工作涉及超临界二氧化碳和液化丙烷作为流动相在政治上活跃的异构体（反式二苯乙烯氧化物和1-(9-蒽基)-2,2,2-）的色谱拆分中的分离特性。实验结果总结如下：(1)二氧化碳、丙烷和三氟乙醇。 (2) 三种溶剂的容量比随着醇浓度的增加而减小，在超临界条件下，容量比也随着压力的增加而减小。这些观察结果可以通过溶质和溶剂分子在活性位点上的竞争吸附来解释。(3) 分离因子随着温度的降低而显着增加，并且根据主要流体的组合和添加乙醇而略有变化。 .亲戚吸附对映体的稳定性主要受吸附相中溶质-聚合物相互作用的控制，其次是吸附相中溶质-溶剂相互作用的控制。 (4) 对映体的分离因子随着超临界流体压力的增加而略有增加，这对应于超临界流体压力的降低。 (5)在以分子扩散和流体浓度混合为主的低速区域，聚合物包覆硅胶的整体传质阻力较小比裸凝胶；然而，在高速区域，聚合物涂覆的硅胶表现出比裸凝胶更高的电阻。可能有两种可能的解释：1)由于夹杂物而增加了多孔颗粒的弯曲系数。 2）由于聚合物附着在颗粒外部而导致颗粒聚结，因此需要对聚合物涂层方法进行基础研究以提高柱效率。