Experimental and theoretical study of recycling in preparative chromatography

To recycle a sample to be separated several times over the column is an efficient tool to improve process performance in preparative liquid chromatography. This technique mimics the application of a longer column. It is possible to recycle the whole sample in a closed loop or to recycle only mixed fractions. The technique is simple to implement and offers a good solvent economy. Several successful applications have been reported mainly from the pharmaceutical industry. In these cases the process design was performed more or less empirically and solely based on standard parameters used in analytical chromatography. Recently some efforts have been undertaken to develop mathematical models taking into account the features of nonlinear chromatography and to evaluate recycling chromatography in comparison to other rivaling techniques. In this paper experimental data will be compared with predictions of the equilibrium dispersion model. It will be shown that this model can be considered as a reliable tool for designing and optimizing recycling chromatography. Finally, recycling is compared to standard batch elution chromatography in terms of recovery, productivity and eluant consumption. © Informa UK Limited, an Informa Group Company [accessed 2014 October 16