Does the guard pre-packed column necessary for your HPLC Column?

Does the guard pre-packed column necessary for your HPLC Column? Oh, it depends.

When the dirty samples are injected into an analytical HPLC column without a guard column many times, the life of the analysis column will be shortened. Depending on the number of injections and the type of samples, chromatographers can choose economical protective columns. A guard column is provided in the solvent flow path before the analysis column.

Protective columns avoid damage caused by particulate matter and strongly adsorbed substances. To maintain adequate capacity for impurities in the sample, a guard column with an inner diameter similar to the column should be selected. Ideally, the packing of the guard column should be the same as that of the analysis column so that the chromatographic performance of the analysis column does not change.

Guard columns participate in separation, so they should be installed online during method development.

It may be difficult to determine when to replace the protective column, and it is best to use experience. As a rough criterion, a change in plate number, pressure, or separation of more than 10% will require the replacement of the protective column. You need to determine the frequency of column replacement based on the application type. It is better to replace the protective column sooner rather than later.

For the guard columns, dead volume is important for end-users.