The capillary column you have received has a “built-in” guard column. The built-in guard column is a 5- to 10-meter section of the capillary column that has been deactivated, but not coated with stationary phase. Because it is an integral part of the capillary column it has been tested for bleed and inertness along with the coated section of the column.
The guard column should be installed into the inlet side of your GC system. When first received, you can easily identify the guard column end of the capillary column by the tag labeled “Guard column end”. Once this tag has been removed, you can still identify the guard column end because it is tied separately from the coated portion of the column on the side of the cage that the metal tag has been attached.
Both the guard column and coated column sections are tied into approximately 5-meter bundles. You can determine the exact length of the guard column by counting the number of column loops and multiplying by 0.56 meters.
As sections of the guard column become contaminated, they can be removed. Typically 1 or 2 loops from the inlet side will need to be removed to bring the column back to acceptable performance. Eventually, all of the guard column may be removed. Once this occurs, a new guard column can be installed using a Press-
Tight® connector (cat.# 20400) or a Vu-Union® connector (cat.# 20418). For more information on guard columns and Press-Tight® or Vu-Union® connectors, please refer to Restek’s Chromatography Products Catalog, or call Technical Service.
