Enhanced Fluidity Liquid Chromatography

High performance liquid chromatography (HPLC) is often the method of choice for the separation of nonvolatile solutes. LC commonly exhibits longer analysis times, larger pressure drops and lower efRciency than either supercritical Suid chromatography (SFC) or gas chromatography (GC). The greater viscosities and lower diffusivities of liquids compared to those of supercritical Suids or gases are the primary cause of these differences in the three types of chromatography. The ideal mobile phase for a chromatographic separation of nonvolatile solutes would combine the positive attributes of liquids and supercritical Suids. That is, a solvent with low viscosity, high diffusivity and high solvent strength is desirable. Enhanced-Suidity liquid mixtures are solvents that have these attributes. These solvents are prepared by dissolving large proportions of liqueRed gases, such as CO2, in commonly associated liquid solvents such as methanol. To date, enhanced-Suidity mixtures such as methanol}CO2, methanol}CO2}H2O, tetrahydrofuran} CO2, hexane}CO2, methanol}Suoroform and methanol}Suoroform}H2O have been used to improve the performance in a range of different types of liquid chromatographies.