Solute–solvent interactions in chemistry and biology. Part 7. An analysis of mobile phase effects on high pressure liquid chromatography capacity factors and relationships of the latter with octanol–water partition coefficients

Abstract

log k′ values on a C₁₈ stationary phase with 90/10, 75/25, 60/40, 45/55 and 30/70 methanol–water mobile phases are correlated in terms of the generalized linear solvation energy relationship, log k′= XYZ_o+mV_I/100 +sπ*+bβ_m+aα_m where V_I is the intrinsic (van der Waals) molar volume, and π*, β_m, and α_m are the solvatochromic parameters that measure solute dipolarity–polarizability, hydrogen-bond acceptor basicity, and hydrogen-bond donor acidity. The correlation equations are combined with the corresponding equation for octanol–water partition coefficients to generate new equations that demonstrate the exact relationships between the various log k's and log K_ow.