Maximising the Lifetime of a HPLC Column Using Guards and Filters

The main cause of deterioration in column performance can often be attributed to contamination of the LC column frit or column packing by the sample matrix, or contaminants produced by wear of the instrument.

In the first instance we would recommend that you check that your column is compatible with the conditions with which you intend using it. This includes pressure, pH, organic solvent and temperature. See the guidance on using individual column phases elsewhere in this guide, or contact technical support for guidance.

In addition we suggest that you use a guard column with your analytical column. This will provide both protection of the column from physical blockage by analyte, matrix components and particulates in the mobile phase, as well as chemical contamination which might otherwise foul the column stationary phase. In many cases a simple Uniguard cartridge design is available which can be screwed directly into the analytical column, eliminating the need for any additional column coupling device.

Guard Selection

Select the guard you need by identifying the prefix from the part number of your analytical column and the internal diameter. Simply take the prefix and add the corresponding suffix from the table below. Then, select any additional items you may require.

For example, a Hypersil GOLD 5µm 150x4.6mm column has the prefix 25005-. Since this column is 4.6mm in diameter, the guard items required for this are: guard cartridges part 25005-014001 and guard holder part 850-00.



Filter Selection

Where the sample is relatively pure, or you wish to apply additional protection from only particulate components then we can also recommend the use of our Unifilter cartridge system or Javelin disposable filters, both of which contain a 0.5µm frit. These filters can also be used elsewhere in the system to provide protection of individual components from mobile phase particulates and particulates resulting from instrument wear.







Using a Guard

The Uniguard or Unifilter design is composed of two parts: the holder and the cartridge (guard or frit). The screw must first be removed from the holder and the cartridge inserted narrow end first. Having finger-tightened the screw back in place, use a spanner to gently apply additional tightening. The Uniguard and Unifilter design can then be screwed directly into the column inlet using finger-tight pressure only.

Javelin guards and filters are designed to be disposed of when blocked. These should be screwed directly into the column inlet using finger-tight pressure only.