Aqueous Size-Exclusion Chromatography

该项目在分析和表面化学计划的支持下，涉及到一个实验和分子模拟研究计划的继续，研究溶质在尺寸排阻色谱（SEC）中的保留现象。教授保罗L. Dubin和他在印第安纳州大学-普渡大学印第安纳波利斯分校的学生选择了具有确定几何形状的各种模型化合物，这些模型化合物指示在多孔玻璃SEC固定相上表现出理想和非理想洗脱特性的球形和不对称溶质。这项研究的动力是推导出严格的理论关系，这些关系将各种溶质的色谱分配系数与它们的尺寸和几何形状相关联。此外，Dubin教授将结合静电效应来模拟SEC的蛋白质分离。将在Superose 12固定相上测量几种高度纯化的模型蛋白的保留特性。电泳光散射和毛细管区带电泳技术也将用于表征高分子量分析物。 水性尺寸排阻色谱法通常用于测定分子量分布和鉴定复杂的合成和天然水溶性聚合物的混合物。该技术中的保留顺序是基于分析物在固定相的不同尺寸的孔中的基于尺寸的分配，其中具有与填充物的几何形状等同的几何形状的那些溶质在柱上保留更长时间。然而，在几何因素不单独控制溶质和固定相之间的相互作用的情况下，SEC固定相上分析物的保留特性可能与校准标准品的保留特性完全不同，这可能导致测量中的粗差。印第安纳州大学的Paul Dubin教授和他的学生将使用各种模型化合物和分子建模算法来推导出将聚合物溶质的保留与溶质尺寸联系起来的基本保留理论。

This project, supported in the Analytical and Surface Chemistry Program, involves the continuation of an experimental and molecular modeling research program studying solute retention phenomena in size exclusion chromatography (SEC). Professor Paul L. Dubin and his students at the Indiana University - Purdue University at Indianapolis have selected various model compounds of defined geometry that are indicative of spherical and asymmetric solutes which exhibit ideal and non-ideal elution characteristics on porous glass SEC stationary phases. The impetus of this study is to derive rigorous theoretical relations which correlate the chromatographic partition coefficient of various solutes with their size and geometry. In addition, Professor Dubin will incorporate electrostatic effects to model protein separation by SEC. The retention characteristics of several highly purified model proteins will be measured at Superose 12 stationary phases. Electrophoretic light scattering and capillary zone electrophoresis techniques will also be used to characterize high molecular weight analytes. Aqueous size exclusion chromatography is commonly used to assay molecular weight distribution and identify mixtures of complex synthetic and natural water soluble polymers. Retention order in this technique is based on the size based partitioning of analyte throughout varying sized pores of the stationary phase, with those solute having geometries equivalent to that of the packing being retained longer on the column. However, in cases where geometric considerations do not solely govern interactions between the solute and the stationary phase, the retention characteristics of analytes at SEC stationary phases can be quite different from that of the calibration standard, which can lead to gross errors in the measurement. Prof. Paul Dubin and his students at Indiana University will use various model compounds and molecular modeling algorithms to derive a fundamental retention theory which relates retention of polymeric solute with solute size.