Agilent Technologies 7890A GC Safety Manual page 9

Dangers unique to GC/MSD operation
Hydrogen presents a number of dangers. Some are general, others are unique
to GC or GC/MSD operation. Dangers include, but are not limited to:
• Combustion of leaking hydrogen.
• Combustion due to rapid expansion of hydrogen from a high-pressure
• Accumulation of hydrogen in the GC oven and subsequent combustion (see
• Accumulation of hydrogen in the MSD and subsequent combustion.
Hydrogen accumulation in a GC/MSD
The GC/MSD cannot always detect leaks in inlet and/or detector gas streams. For
WA RN ING
this reason, it is vital that column fittings should always be either connected to a
column, or have a cap or plug installed. The H
hydrogen so that the GC is aware of hydrogen use.
All users should be aware of the mechanisms by which hydrogen can
accumulate (Table 1) and know what precautions to take if they know or
suspect that hydrogen has accumulated. Note that these mechanisms apply to
all mass spectrometers, including the GC/MSD.
Table 1
Mechanism
Mass spectrometer turned off
7890A GC Safety Manual
cylinder.
your GC documentation and the label on the top edge of the GC oven door).
Potential hydrogen accumulation mechanisms in GC/MSD
streams must be configured for
2
Results
A mass spectrometer can be shut down
deliberately. It can also be shut down accidentally
by an internal or external failure. A mass
spectrometer shutdown does not shut off the flow
of carrier gas. As a result, hydrogen may slowly
accumulate in the mass spectrometer.
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