Hint:

The type of bleeding experienced varies with each septum type, and appear as different patterns on the chromatogram. When conducting high sensitivity analysis, a septum which does not exhibit bleeding in a position that would obstruct the peak of the target compound needs to be chosen. In addition, performing conditioning for a few hours at about 120 deg.C to 150 deg.C (up to about 200 deg.C for the LL, HT septums) after extraction with hexane for a few hours may reduce bleeding.