RETENTION BEHAVIOR OF P-ALKYLPHENOLS IN REVERSED-PHASE LIQUID-CHROMATOGRAPHY USING ETHANOL WATER MIXTURES/

The retention behavior of p-alkylphenols was studied in reversed-phase liquid chromatography using octadecylsilyl-silica gel and ethanol/wat er mobile phases. The results were compared with those in methanol/wat er systems. Linear correlations were observed between the logarithmic retention factor (ln k) and the carbon number of side chains in the so lutes, irrespective of the type and volumetric fraction (phi) of the o rganic modifiers in the mobile phases. The straight lines measured at different phi converged at almost one point. By analyzing the slope of the linear correlations, a functional contribution of a methylene gro up to k and a reduction of the hydrophobic surface area of the solutes and octadecylsilyl ligands due to the retention were estimated. It wa s also attempted to analyze the characteristics of the retention in re versed-phase liquid chromatography on the basis of solvophobic theory.