Evaluation of a Simple HPLC Correlation Method for the Estimation of the Octanol-Water Partition Coefficients of Organic Compounds

Abstract

A simple reverse-phase high performance liquid chromatographic method is evaluated for the estimation of octanol-water partition coefficients (log P) of organic compounds by correlation with their chromatographic capacity factors (k′). Using an unmodified commercial octadecylsilane column and a mobile phase consisting of methanol and an aqueous buffer, a linear relationship is established between the literature log P values of 68 compounds and the logarithms of their k′ values. For the determination of the partition coefficients of unknowns, one of two sets of standards is used to calibrate the system, the choice being dependent on the hydrogen-bonding character of the compounds being evaluated. The overall method is shown to be rapid and widely adaptable and to give log P data which are comparable to results obtained by classical or other correlation methods.