Should I use a guard column?

A guard column is almost always recommended for use in your system, especially when you have components in your sample that may harm your sensitive stationary phase. At times you may find that some components in your sample seem to permanently bond with your stationary phase, eventually decreasing the efficiency and usefulness of the column, forcing early replacement.

When using a guard column packed with a similar stationary phase to that of your primary analytical column, it is possible to significantly increase the life of your column.

The guard column is a relatively low-cost product, designed to selectively filter out those components that might cause damage to your primary column. By allowing the harmful components in your sample to interact with its stationary phase material, the guard column keeps those components from exerting their effects on your analytical column’s packing. However, keep in mind that because the harmful components of your samples are interacting with the guard column, it must be replaced from time to time. This can be monitored by keeping track of the back pressure exerted by your column system. When the back pressure increases significantly, that should serve as a good indicator that it is time to replace your guard column.