Temperature gradients in preparative high-performance liquid chromatography columns

One rarely investigated but important factor in the performance of HPLC columns is temperature. It influences the thermodynamic and hydrodynamic properties of the column. The subject of this work is the distribution of temperature within the column bed. Analytical columns operated at high flow-rates, and large diameter columns packed with small particles are subject to Viscous heat dissipation which can seriously affect the quality of the separation. Since the thermal conductivity in a packed column is rather weak, axial and radial temperature profiles will appear in the chromatographic bed. The present paper reports temperature profiles measured in a preparative LC column of 60 mm diameter as a function of the packing material, the eluent flow-rate and the eluent composition. Van Deemter plots show the influence of temperature on the separation process. The influence of the operating parameters on the performance of the column is discussed.