Retention characteristics of silica materials in carbon dioxide/methanol mixtures studied by inverse supercritical fluid chromatography.

In this work, inverse supercritical fluid chromatography was applied to characterize the surface of four silica materials (three commercial Kromasils and one silica aerogel) from chromatographic retention data. Retention factors at various pressures (150-300 bar), temperatures (25-60 °C) and modifier concentrations (5-20 vol.% methanol in CO) for a set of representative 17 solutes were correlated with the solute properties by the linear solvation energy relationships (LSER).