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.
