Gas Selection - Agilent Technologies 7820A GC Site Preparation Manual

Gas Selection

Table 6 Gases usable with Agilent GCs and capillary columns
Detector type
Electron capture (ECD)
Flame ionization (FID)
Nitrogen-Phosphorus (NPD)
Thermal conductivity (TCD)
* Depending on bead type, higher makeup gas flow rates (> 5 mL/min) may introduce cooling effects or shorten bead life.
Table 7 Gases usable with Agilent GCs and packed columns
Detector type
Electron capture (ECD)
Flame ionization (FID)
Nitrogen-Phosphorus (NPD)
7820A GC Site Preparation Guide
Table 6 lists gases usable with Agilent GCs and capillary
columns. When used with capillary columns, GC detectors
require a separate makeup gas for optimum sensitivity.
Carrier Preferred makeup
Hydrogen Argon/Methane
Helium Argon/Methane
Nitrogen Nitrogen
Argon/Methane* Argon/Methane
Hydrogen Nitrogen
Helium Nitrogen
Nitrogen Nitrogen
Helium Nitrogen
Nitrogen Nitrogen
Hydrogen Must be same as
Helium carrier and
Nitrogen reference
Table 7 lists gas recommendations for packed column use. In
general, makeup gases are not required with packed columns.
Carrier gas
Nitrogen
Argon/methane
Nitrogen
Helium
Helium
Nitrogen
7820A GC Site Preparation
Alternate choice
Nitrogen
Nitrogen
Argon/Methane
Nitrogen
Helium
Helium
Helium
*
Helium
Helium
Must be same as
carrier and
reference
Comments
Maximum sensitivity
Maximum dynamic range
Maximum sensitivity
Acceptable alternative
Optimum performance
Acceptable alternative
Detector, anode
purge, or reference
Anode purge must
be same as makeup
Hydrogen and air for
detector
Hydrogen and air for
detector
Reference must be
same as carrier and
makeup
Detector, anode purge, or
reference
Nitrogen
Argon/Methane
Hydrogen and air for
detector.
Hydrogen and air for
detector.
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