Selectivity of the stationary phase in gas-liquid chromatography

Abstract

Various methods have been given for testing the selectivity of the stationary phase for the following cases of separation: separation with respect to dipole moment, separation with respect to electron-accepting or electron-donating groups, separation with respect to ability to form hydrogen bonds, separation of isomers, and separation of homologous series. Comparative characteristics of the selectivity of a number of stationary phases at different temperatures have been determined. It has been shown that the structure of the stationary phase plays a particularly important part in the production of both enthalpy selectivity and entropy selectivity. It has been shown that the entropy selectivity of the stationary phases decreases with increase in temperature. Increase in temperature facilitates the interaction between the polar groups of the substances being separated and the stationary phase.