Ligand exchange chromatography (LEC) using physically impregnated N-hexadecyl-L-hydroxyproline on commercially available RP-18 column is applied for the preparative separation of amino acid racemic mixtures. The equilibrium dispersive model was used for the mathematical prediction of the separation process. The experimental determination of the model parameters is discussed. Using the multi-component competitive Langmuir adsorption isotherm the mathematical model was able to predict the preparative separation behaviour of low concentrated feed solutions of amino acid racemats. The calculated profiles very well predict the break-through experiments (adsorption and desorption) as well as the injection experiments. At a high concentrated feed overloading effects in the break-through adsorption experiments were detected and a discussion on model limits is given. (c) 2006 Elsevier B.V. All rights reserved.