Resolution of Enantiomers by Supercritical Fluid Chromatography with Cellulose Tris(phenylcarbamate) Coated on Silica Gel

Article abstract of DOI:10.1246/bcsj.63.1365

The solvent characteristics of super- and subcritical carbon dioxide for the chromatographic resolution of enantiomers (trans-stilben oxide) by chiral cellulose tris(phenylcarbamate) were investigated by altering the pressure (10, 15, 20, and 40 MPa), the temperature (0, 25, and 40 deg C), and the concentrations of the modifiers.Among methanol, ethanol, and 2-propanol used as modifiers, methanol is the most effective in terms of the resolution of enantiomers, though 2-propanol gives a slightly high value for the separation factor.When the concentration of alcoholic increases, the capacity ratio decreases substantially, but the separation factor decreases only a little.At 40 deg C, an increase in pressure results in a decrease in the capacity ratio and a slight increase in the separation factor.These pressure effects may be attributed to the enhanced solubilities of both the solute and the modifier with an increase in the mobile-phase density.The temperature is the most effective variable for the separation factor of enantiomers; it increases as the temperature lowers.Therefore, the resolution becomes higher at 0 deg C (subcritical conditions) than at 40 deg C on the basis of the same analysis time.