Planarity Recognition of Polycyclic Aromatic Hydrocarbons in Supercritical Fluid Chromatography

选择性是实现结构相关化合物分离以进行鉴定和定量的最重要变量之一。在液相色谱（LC）中，可以通过改变流动相组成、柱温和/或固定相的类型来控制选择性。可以使用溶剂体系来改变液相色谱的选择性。然而，在超临界流体色谱（SFC）中，流动相的选择非常有限；最常用的流动相是二氧化碳，有时会加入修饰剂。虽然可以通过改变温度和压力等状态变量以及添加改性剂来改变选择性，但预计选择性不会发生大的变化。在SFC中达到理想选择性的最有效方法是改变固定相的类型。利用填充式毛细管SFC，可以使用各种类型的固定相，这些固定相在LC中具有不同的选择性。本研究的主要目的是研究LC和SFC在使用相同固定相时的选择性差异，特别是关注它们识别多环芳烃分子平面度差异的能力。然后，我们将在SFC中研究在LC中具有不同选择性的新固定相，以了解LC与SFC的基本区别。结果发现，液晶键合相和环糊精键合相在分子平面度识别方面比LC中具有更好的选择性。由于在SFC流动相中溶剂化对溶质-固定相相互作用的影响比LC情况下小，因此在色谱环境中几乎可以进行简单的分子-分子相互作用。基于分子-分子相互作用的新固定相设计可以很容易地在SFC条件下进行评估，而不是在LC条件下。所得的信息可以用于预测这种固定相在LC中的实际性能。设计对特定分离具有更高选择性的新固定相的方案是：设计分子间相互作用，根据相互作用考虑固定相的结构，合成相，用填充柱SFC评价其性能，然后将其应用于LC。研究结果清楚地表明，该方案是在LC中获得高选择性固定相的最佳方法之一。少

Selectivity is one of the most important variables to achieve the separation of structually related compounds for identification and quantitation. In Liquid chromatography (LC), selectivity can be controlled by changing the mobile phase composition, the column temperature and/or the type of stationary phases. It is possible to use solvent systems to change selectivity in LC. However, the choice of mobile phases in supercritical fluid chromatography (SFC) is very limited ; the most popular mobile phase is carbon dioxide, into which modifiers are sometimes added. Large changes in selectivity will not be expected, although it is feasible to modify the selectivity by changing the state variables such as temperature and pressure and adding mofifiers. The most effective approach to attain the desiable selectivity in SFC is to alter the type of stationary phases. With packed capillary SFC, various types of stationary phases which offer different selectivity in LC can be utilised. The main pur … More pose of this investigation is to examine the difference in selectivity between LC and SFC using identical stationary phases, especially focusing on their ability to recognize the difference in molecular planarity of polycyclic aromatic hydrocarbons. Then new stationary phases which have different selectivity in LC will be examined in SFC in order to know the basic difference between LC and SFC. As the results, we have found that liquid-crystal bonded phase and cyclodextrin bonded phase have better selectivity in molecular planarity recognition than those in LC, because in SFC mobile phase solvation effect to the solute-stationary phase interaction is smaller than that in LC situation and therefore almost simple molecular-molecular interaction is possible to make in chromatographic environment. The design of new stationary phases based on molecular-molecular interaction can be easily possible to evaluate in SFC, rather than LC conditions. Then the resulted information can be useful to predict the actual performance of such stationary phases in LC. The scheme of designing new stationary phases which can give us better of higher selectivity for particular separations is as follows : design the molecular-molecular interaction, consider the stationary phase structure based on the interaction, synthesize the phase, evaluate the performance by packed column SFC and then apply it in LC. The results of this investigation can clearly indicate this scheme is one of the best way to obtain highly selective stationary phases in LC. Less