The influence of the mobile phase composition on the chromatography dynamics of normal-phase chromatography has been investigated. The adsorption equilibrium of components: cyclopentanone-hexane and ethyl acetate-hexane have been measured. The model of heterogeneous adsorption for the solute including the adsorption equilibrium of the solvent has been coupled with a model of the column dynamics and validated on the basis of the experimental chromatograms.