Abstract
A chromatographic technique was used to experimentally study the effects of solvent concentration on sorption and diffusion of cresols in a bonded β-cyclodextrin-silica with a mixed solvent of methanol and water as mobile phase. A distribution model that accounts for the non-ideality caused by the different degrees of interaction with the stationary phase for the solute and solvent components was proposed, based on the mechanism of multi-component competitive adsorption, to describe the solvent concentration dependence of the distribution coefficient. The results showed that the distribution model is in good agreement with the experimental data. The axial dispersion, external film mass transfer and intraparticle diffusion were found to be dependent on the solvent concentration. An analysis of the solvent concentration effect on the intraparticle diffusion in the range of 33.3 mol/l ≤ c1 ≤ 49.95 mol/l indicated that the effect of solvent concentration on restricted diffusion is large in comparison with the solvent concentration effect on non-restricted diffusion for each cresol.
