Liquid chromatographic retention of β-diketonato complexes of chromium(III) and palladium(II) in octadecyl-bonded silica/water—methanol systems : Comparison with liquid—liquid partition using dodecane as a model alkyl-bonded phase

Abstract

Capacity factors have been measured for several β-diketonates of chromium(III) and palladium(II) on an octadecyl-bonded silica (ODS) stationary phase with a water—methanol binary mobile phase. The capacity factor decreases with increasing methanol content of the mobile phase. In series of chromium complexes and palladium complexes, the capacity factor increases with increase in the molar volume of the complex. A chromium complex exhibits a smaller retention than the corresponding palladium complex if they have the same molar volumes. The capacity factor of each metal complex on the ODS phase can be related to the partition coefficient in the dodecane/water—methanol system when the contribution of solute—solvent inter-action is taken into account.