In the pharmaceutical industry, the increasing demand of new single enantiomer products has raised a great interest towards chromatographic separation methods. While analytical applications of high performance liquid chromatography and gas chromatography are well established, the scaling up to preparative applications still needs a better comprehension and rationalization of the elementary phenomena involved.In this work the analytical and preparative separation of an isoxazoline racemic mixture on triacetylcellulose has been studied. In order to determine the thermodynamic properties and the equilibrium isotherms of adsorption several experiments at very low concentration (in a HPLC column) and at higher concentration (using the frontal analysis technique) have been performed. Moreover, pulse experiments on a preparative column have been run at different temperature and at different racemic concentration, The comparison between experimental data and model results is discussed.