Elevated temperatures are required for optimal peak efficiencywhen using polymeric ligand-exchange HPLC columns. Bysupplementing elevated temperature with a simple pre-heatdevice, peak efficiency is further enhanced, sometimesdramatically. The graphs below demonstrate the importance ofboth elevated temperature and eluent preheating on efficiency.This study was performed on our BP-800 Ca column, 300 x 7.8mm. Efficiency is enhanced by using higher temperature and alsoa Benson pre-heat coil, which reduces radial and axialtemperature gradients.