Guard columns

Kromasil^® guard columns

Guard columns are short (10 mm length) columns containing chromatographic media that can be connected in front of the HPLC column. The guard column purpose is to extend the lifetime of the HPLC column by serving as a filter and a pressure dampener.

The guard column contains a cartridge which is packed with the same stationary phase as the columns. It will accumulate particle impurities from the inlet liquid phase at the head of the cartridge. These particles can be coming from poor quality solvents, sample precipitates, or salts generated by buffer incompatibility with the mobile phase’s organic component. Samples containing heavy oils or greases can also affect the lifetime of the column as these highly hydrophobic excipients will bind irreversibly to the stationary phase. A guard column will minimize these effects.

When the system pressure starts rising, it could be a sign that the guard column has reached its lifetime. The guard cartridge needs to be replaced to prolong the chromatographic performance of the main column.

Kromasil guard columns are built of 3 parts:

• A cartridge: This is the expendable column packed with the same packing as the HPLC column the user intends to protect. It's 1 cm long. Cartridges are sold in 5 and 3 pack for analytical and semi-preparative columns, respectively.
• A holder: A stainless steel container for the cartridge.
• A coupler: A PEEK connector or a short capillary tubing (for larger prep columns) to attach the guard column at the inlet of the HPLC column.

A Guard starter kit for analytical columns contains one holder, one coupler and a 5 pack of cartridges of the actual silica packing.

Available instructions for download

Quick starter guide for analytical guard columns (pdf)

Quick starter guide for 30-50 mm i.d. semi-prep guard columns (pdf)