The usefulness of the UNIFAC activity coefficient estimation method for understanding the magnitude of solute-solvent interactions in gas and liquid chromatography has been investigated. To demonstrate the power of UNIFAC it was used to investigate the origin of the Martin equation, to explore the methylene group selectivity and relative retention in reversed-phase liquid-liquid partition chromatography, to examine solute- solvent interactions in eluents in normal-phase liquid chromatography and to examine mixed stationary phase effects in gas-liquid chromatography. Although not accurate enough to be useful for quantitative predictions of retention, UNIFAC is fairly useful in explaining a wide variety of issues of general importance in chromatography such as the prediction of the order of elution of polar versus non-polar solutes and the relative strengths of solvents in all types of chromatography.
Bibliographical noteFunding Information:
Work at the University of Minnesota was sup-portedi n part by a grantf rom theN ational Science Foundation.