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Installing GC Columns
1
Conditioning a column before it is installed into the GC/MSD
interface is essential
A small portion of the capillary column stationary phase is often carried
away by the carrier gas. This is called column bleed. Column bleed deposits
traces of the stationary phase in the MSD ion source. This decreases MSD
sensitivity and makes cleaning of the ion source necessary.
Column bleed is most common in new or poorly cross-linked columns. It is
much worse if there are traces of oxygen in the carrier gas when the column
is heated. To minimize column bleed, all capillary columns should be condi-
tioned
they are installed in the GC/MSD interface.
before
Conditioning ferrules is also beneficial
Heating ferrules to their maximum expected operating temperature a few
times before they are installed can reduce chemical bleed from the ferrules.
Tips and hints
• Note that the column installation procedure is different from that for
other Hewlett-Packard mass spectrometers and MSDs. Using the
procedure from another instrument will not work.
• For optimal sensitivity performance, install your caapillary column
without using the installation tool.
• You can remove old ferrules from column nuts with an ordinary push pin.
• Always use carrier gas that is at least 99.999% pure.
• Because of thermal expansion, new ferrules may loosen after heating and
cooling a few times. Check for tightness after two or three heating cycles.
• Always wear clean gloves when handling columns, especially the end that
will be inserted into the GC/MSD interface.
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