Methods for Thermodynamic Analysis of Temperature Dependence of Distribution Coefficients in Chromatography Separations

Abstract

Thermodynamic analysis of chromatography separation is important not only for optimization of separation but also development of new separation media and processes. In this study temperature dependence in the separation of two model components (polyphenols) by polymer-based chromatography with ethanol-water mobile phase was analyzed by van’t Hoff plots and isothermal titration calorimeter (ITC). The distribution coefficient K obtained by the isocratic elution of chromatography was employed both for van’t Hoff plots and for the calculation of adsorbed amount in the ITC measurements. Enthalpy values obtained by both methods were similar. As ITC is not able to predict separation behavior, it is recommended to use chromatography experiments as a complimentary method for analyzing the temperature dependence of separation.