超临界流体色谱中溶质的保留行为

超临界流体色谱中热力学参数最佳化和动力学最佳化同等重要。溶质的保留行为和物质对的分离受柱固定相和流动相各种参数的影响。在本研究中,使用纯CO_2作为流动相,饱和烃、芳烃、以及它们的硝基取代物作为溶质,对上述影响进行了系统地考察。结果发现影响物质对分离的(以分离系数,α,表示)最主要因素是流体的密度。而温度的影响并不明显。柱固定相的性质也有一定程度的影响。在柱固定相相同的情况下,改变操作参数,溶质峰的洗馏顺序可能出现倒置。表明在超临界流体色谱中流动相溶解能力的重要作用。实验结果为了解和优化超临界流体色谱热力学参数提供了依据。

Retention Behavior of Solutes in Supercritical Fluid Chromatography

The purpose of this work was to study the retention behaviors of some solutes and findoptimum thermodynamics conditions in Supercritical Fluid Chromatography (SFC). The workwas performed in packed columns, which were ODS-, Phenyl-and Cyano-bonded to silicagel, and PBD alumina columns. Hydrocarbon, aromatic hydrocarbon, and their derivatives werechosen as test solutes. The rule of retention and resolution of test solutes in the columns withdifferent functional groups and the dependence of retention and separation of solutes on opera-tion parameters were systematically investigated. In this study, it has been found that using pure CO_2 as mobile phase the separating coe-fficient of above solute strongly depends on the density of mobile phase, but not on the tempe-rature. The results provide an experimental and theoretical basis for optimizing operation para-meters in SFC.