Characterization of Amino- and Cyano-alkyl Bonded Silica Phases in Liquid-Solid Chromatography. II. Relative Strength of Strong Solvents in Binary Systems for Steroid Solutes
The retention behaviors of 15 steroid hormones were systematically examined in an ethanol-containing binary eluent. On the basis of a linear relationship between the logarithm of the capacity ratio and that of the solvent composition, the retentivities of amino, cyano and bare silica columns were determined. These columns all showed similar affinity, and stronger adsorption was observed for phenolic solutes while weaker adsorption was shown for acyl derivatives in the case of amino-type columns than that for other columns. The relative solvent strength of ethanol to ethyl acetate in n-hexane-binary solvents was confirmed by use of these 3 columns. The relative strength of ethanol to ethyl acetate increased especially in amino-type and bare silica columns.