Adsorption from solvent mixtures with varying composition

To achieve a desired separation using adsorption processes usually two distinct steps are needed (adsorption/regeneration). Thus, certain operating conditions are changed periodically. During the two half periods usually the operating conditions are kept constant (isocratic operation). A potential for improvement is offered if during the process operating parameters are altered systematically. To realize such gradient concepts several operating parameters might be modulated depending on the type of process. Possible parameters are e. g. temperature, flowrate, ionic strength and pH. In this paper we consider liquid chromatographic separations under the influence of forced solvent composition gradients