A Model of Liquid Adsorption Chromatography Involving Solute-Solvent Interaction in the Mobile Phase, Energetic Heterogeneity of the Adsorbent, and Differences in Molecular Sizes of Solute and Solvents

Abstract

A simple model for liquid-solid chromatography (LSC) process with mixed mobile phases has been proposed. According to this model the LSC process is represented by suitable reversible phase-exchange reactions between molecules of solute and solvents and reversible solute-solvent reactions in the mobile phase. These reactions describe the competitive adsorption of solute molecules and formation of solute-solvent complexes in the mobile phase. Analytical equations for the capacity ratio, derived in terms of the model, involve solute-solvent interaction in the mobile phase, differences in molecular sizes of solute and solvents, energetic heterogeneity of the adsorbent and ideality of the ourface phase. Linear forms of these equations are very convenient for analysing the experimental chromatographic data.