Prediction adsorption coefficients (KOC) for aromatic compounds by HPLC retention factors (k')

The prediction of soil adsorption coefficients (Koc) of substituted aromatic compounds including polar and non-polar chemicals via Reversed-Phased High Performance Liquid Chromatography (RP-HPLC) capacity factors (k') has been studied, including the effect of mobile phase composition and the inclusion of a variable which relates to non-hydrophobic interactions on the correlation between log Koc and log k'. Linear relationships are significantly improved when either the molecular connectivity indices (MCI) relating to non-dispersive intermolecular interactions or the hydrogen-bonding indicator variable is included in the correlation between log Koc and log k'. By using log k'w, a theoretical capacity factor which has been obtained by extrapolation of retention data in a binary solvent system to pure water eluent, the correlation between log Koc and log k'w is better than using log k'.