Understanding and Development of New Materials for High Performance Liquid Chromatography and Electrophoresis

我的研究小组在分析分离方面很活跃。高效液相色谱在化学、生物化学和工业实验室中普遍存在。近年来，高效液相领域出现了许多创新--超高性能LC、核壳相和亲水作用层析，仅举几例。 我的团队采取的方法是发展对方法论的基本物理化学理解。然后，我们利用这种理解来加强和增强分析方法。 在这一宏大的规划目标范围内，DG提案的短期目标是开发和研究用于亲水相互作用的液相色谱、正相液相色谱和毛细管电泳用的新型极性表面，并对多孔石墨炭进行极性修饰，以减弱其强烈的反相吸附。 多孔石墨炭具有良好的化学稳定性和独特的选择性，是一种很有吸引力的高效液相色谱相。在我们过去成功的基础上，我们将利用重氮化学将包括酰胺、儿茶酚、糖和聚氧乙烯在内的极性官能团引入碳表面。这种极性修饰将增强高效液相色谱分离的多种模式。在无处不在的反相液相色谱中，我们的极性修饰将减弱限制碳高效液相颗粒使用的过度保留和峰拖尾。亲水作用液相色谱是一种快速发展的高效液相色谱分离模式，但该模式被限制在pH 2-8和&60℃。最后，正相高效液相色谱法目前在二氧化硅和衍生二氧化硅上进行-其保留特性由底层二氧化硅的局域极性决定。我们的极性碳将提供极性位置来自非极性碱基的固定相-允许更纯粹地控制正相液相色谱中的保留。 我们还将研究使用pi-pi吸附策略对多孔碳高效液相色谱颗粒进行简单的修饰，这种策略在碳纳米材料的修饰中很流行。用非离子表面活性剂对碳进行修饰的初步结果表明，这种修饰在一系列溶剂中是稳定的。 毛细管电泳用极性亲水涂层的开发将补充我们对极性色谱相的研究，并提供各种分析分离方法的培训机会。 上述工作将与对液相色谱中极性相互作用性质的基础研究交织在一起。我们考察了：非传统溶剂对亲水作用的影响；温度对保留和选择性的影响；以及正相色谱中极性作用的局部化。

My research group is active in analytical separations. High performance liquid chromatography (HPLC) is ubiquitous in chemistry, biochemistry, and industrial labs. Recent years have seen many innovations in the field of HPLC – ultrahigh performance LC, core-shell phases, and hydrophilic interaction chromatography to name but a few. The approach my group takes is to develop a fundamental physico-chemical understanding of the methodology. We then use that understanding to enhance and empower the analytical methods. Within this broad programmatic objective, the short term objective of this DG proposal is to develop and investigate novel polar surfaces for hydrophilic interaction liquid chromatography, normal phase liquid chromatography, and capillary electrophoresis, and to introduce polar modification to porous graphitic carbon to attenuate its strong reversed phase adsorption. Porous graphitic carbon is an attractive phase for HPLC due to its chemical stability and unique selectivity. Building on our past success, we will introduce polar functionalities including amide, catechol, saccharide and poly(oxyethylene) to the carbon surface using diazonium chemistry. This polar modification will enhance multiple modes of HPLC separation. In the ubiquitous reversed-phase liquid chromatography, our polar modifications will attenuate the excessive retention and peak tailing that limits the use of carbon HPLC particles. Hydrophilic interaction liquid chromatography is a rapidly growing mode of HPLC, but one that is restricted to pH 2-8 and <60°C. Our polar carbon phase will expand the separation conditions that can be used. Finally, normal-phase HPLC is current performed on silica and derivatized silica – whose retention character is dictated by the localized polarity of the underlying silica. Our polar carbon will provide stationary phases whose polar sites arise from a non-polar base – allowing purer control of retention in normal-phase liquid chromatography.  We will also investigate the facile modification of porous carbon HPLC particles using pi-pi adsorptive strategies that are popular for modification of carbon nanomaterials. Preliminary results with non-ionic surfactants on carbon indicate that the modification is robust under a range of solvents. Development of polar hydrophilic coatings for capillary electrophoresis will complement our studies of polar chromatographic phases, and provide training opportunities in a diversity of analytical separation methodologies. The above work will be interwoven with fundamental studies of the nature of polar interactions in liquid chromatography. We investigate the impact of: non-traditional solvents on hydrophilic interaction liquid chromatography; temperature on retention and selectivity; and localization of polar interactions in normal phase chromatography.