The analytical column is the heart of any liquid chromatography system and remains the most problematic component. HPLC columns accumulate retained material which can dramatically reduce longevity and cause costly downtime costs resulting from premature column failure and troubleshooting efforts. The best way to protect an analytical column from fouling is to install a guard column between the injection valve and the analytical column. The guard column traps particulates, solvent impurities, and retained sample components. The ideal guard column should have no effect on the separation. In order to achieve this, a guard column with matching bonded phase and optimal hardware configuration should be selected.