Use of Enhanced Fluidity Liquid Mixtures in Separation Science

该项目得到了分析和表面化学计划的支持，涉及对增强型流动性液相色谱基本原理的持续研究。增强型流动相是通过在高温下将大量可压缩流体(如二氧化碳)添加到典型的液相色谱洗脱液中而开发出来的。其结果是产生了类似于超临界流体色谱(SFC)的更高效率和更快的分离。俄亥俄州立大学的Susan Olesik教授和她的学生将使用粘度、密度、扩散系数、溶剂强度和溶质偏摩尔体积测量来表征不同温度和压力下增强型流体混合物的宏观和微观性质。这些溶剂组合也将应用于反相、正相和尺寸排除层析。此外，这项技术还将用于开发一种新的色谱技术--液体吸附临界色谱仪(LACC)，用于测定聚合物的官能团分布。液相色谱(LC)是工业上应用最广泛的分析方法之一，在它出现的过程中，人们认为超临界流体色谱(SFC)能够将LC和GC的功能和应用融为一体。然而，事实并非如此，主要的缺点是超临界流体溶解极性分析物的能力很差。Olesik教授设想了一种使用超临界流体产生流动相的新转变，能够溶解更广泛的分析物，并显著提高分离效率和速度，而不是传统的液相色谱技术。

This project, supported in the Analytical and Surface Chemistry Program, involves the continued study of the fundamentals of enhanced fluidity liquid chromatography. Enhanced-fluid mobile phases are developed by adding large portions of compressible fluids such as carbon dioxide to typical liquid chromatography eluants at elevated temperatures. The result is the generation of higher efficiency and faster separations similar to those exhibited in supercritical fluid chromatography (SFC). Professor Susan Olesik and her students at Ohio State University will characterize the macroscopic and microscopic properties of enhanced fluid mixtures at various temperatures and pressures using viscosity, density, diffusion coefficient, solvent strength, and solute partial molar volume measurements. These solvent combinations will also be applied in reverse-phase, normal-phase, and size exclusion chromatographies. In addition, this technology will be used in the development of a novel chromatographic technique coined `liquid adsorption critical chromatography` (LACC), which is applied to the determination of polymer functional group distribution. Liquid chromatography (LC) is one the most widely used analytical methods in industry and during its advent supercritical fluid chromatography (SFC) was thought capable of incorporating the power and applications of LC and gas chromatography into one technique. However this was not found to be so, with the major disadvantage being the poor ability of supercritical fluids to dissolve polar analytes. Prof. Olesik has conceived of a new twist on the use of supercritical fluids to yield mobile phases capable of dissolving a much wider range of analytes with a significant enhancement in the efficiency and speed of separations over that exhibited by the traditional liquid chromatographic techniques.