HPLC column performance can suffer from sample impurities. A range of tools are available to protect the column and retain performance. The simple addition of a low porosity 0.5 or 2 μm on-line filter can protect from physical impurities whilst a guard cartridge is one of the best means to protect against chemical sample pollution. Guard cartridges are typically packed with the same phase as the HPLC column - they should be changed on a regular basis for optimal protection.
