Liquid chromatographic retention studies using polystyrene-divinylbenzene stationary phases in reversed-phase and normal-phase eluents

Polystyrene-divinylbenzene (PS-DVB) stationary phases were used for the study of solute retention in high-performance liquid chromatography. Non-aqueous mobile phases were used to observe analyte retention behavior without regard to the influence of water. Separations with a single 100% solvent as the mobile phase allowed comparison of solvents for their relative ability to elute analytes with respect to size and functionality. In binary non-aqueous mobile phase mixtures, plots of log ;A method based on the equilibrium between solute and solvent was also proposed for the interpretation of retention data in HPLC. Plots representing changes in retention as a function of mobile-phase composition showed linear dependence for nearly the entire range of solvent composition for nonaqueous binary systems. Plots of retention versus molar concentration of methanol unassociated with water showed acceptable linearity over almost the entire range of eluent composition. The slope of the graph was interpreted to be the average combining ratio of solvent molecules to solute molecules. The results from the methanol/water system lend chromatographic support to the hypothesis of Scott et al. that a 1:1 methanol/water associate exists in methanol/water mobile phase mixtures.;In separate work, a series of columns of increasing sulfonation capacity were used to study the effect of polystyrene-divinylbenzene sulfonation on solute retention in conventional reversed-phase and normal-phase eluents. Solutes chromatographed using a reversed-phase eluent showed a decrease in retention as sulfonation capacity was increased. In the presence of a predominantly organic mobile phase, polar compounds were retained longer with an increase in sulfonation capacity. Plots of log...