To protect the separation column from contamination and/or premature ageing, we recommend using either guard columns, guard cartridges or pre-column filters. In addition, it is recommended that each analyte solution is filtered through a syringe filter (0.45 µm or 0.2 µm) before injection in order to minimise the proportion of dust particles and suspended particles. So-called Ghost-Guard-LC columns effectively protect the separation column from non-polar impurities from the mobile phase and thus eliminate the problem of unwanted ghost peaks or poor baselines.
