Adsorption-driven retention in normal-phase chromatography with ternary mobile phases

The model for retention in chromatographic systems using ternary mobile phases is considered. The driving force for the separation is assumed to be only a difference in adsorptive properties of a solute and all solvents. The effects of mobile phase composition are discussed. A series of very simple dependences between parameters characterizing retention in ternary and binary solvents is presented. The linear relationship is proposed to predict the capacity factor in the ternary mobile phase, for which the ratio of mole fractions of two less-polar solvents remains fixed. Theoretical concepts are verified by comparing the calculated values with experimental data measured in the entire concentration region.