THERMODYNAMIC INVESTIGATION OF SAMPLE RETENTION MECHANISM IN ION-EXCLUSION CHROMATOGRAPHY WITH INCLUSION COMPOUND IN THE MOBILE-PHASE

In this paper the retention mechanism of the solute retention in ion:exclusion chromatography with beta-cyclodextrin in the mobile phase is presented. The values of the adsorption and inclusion constants are estimated from the dependence of solute retention on cyclodextrin concentration. From the van't Hoff dependence the entropy and enthalpy changes are determined. It was found that increase of the temperature decreases the adsorption and the complexation constants. For adsorption negative values were obtained for enthalpy and entropy changes. Negative values for enthalpy and positive values for entropy changes were obtained for complexation.