8
7890 Series GC Site Preparation Checklist
Issued: 09-Dec-2015, Revision: 1.8
Copyright
2013
Agilent Technologies
Page 8 of 15
26B
27B
Gas Selection
12B
Special Notes
1.
Refer to the "Gas and Reagent Selection" section in the "Agilent GC, GC/MS and ALS Site
Preparation Guide" for more detail.
2.
Agilent recommends a carrier and detector gas purity of 99.9995% or better. Air for flame
detectors should be zero grade. Agilent also recommends using traps to remove hydrocarbons,
water, and oxygen.
3.
When used with capillary columns, GC detectors require a separate makeup gas for optimum
sensitivity. This table lists gas recommendations for capillary columns and the preferred makeup
gas types.
4.
The inlet electronic pressure control (EPC) modules are calibrated for up to 4 carrier gases:
Split/Splitless capillary (SS), Purged packed (PP), Programmable temperature vaporization
(PTV), Multi-Mode (MM), and cool on-column (COC) are calibrated for Helium, Hydrogen,
Nitrogen, and Argon methane 5%.
Volatiles inlet VI is calibrated for only Helium and Hydrogen.
5.
For GC/MS requirements, refer to the "GC/MS Gas and Reagent Requirements" section in the
"Agilent GC, GC/MS and ALS Site Preparation Guide"
Detector
Carrier gas
Make up
1st choice
Make up
2nd choice
Purge or reference
Electron
capture
Hydrogen*
Helium
Nitrogen
Argon/methane
Argon/methane 5%
Argon/methane 5%
Nitrogen
Argon/methane 5%
Nitrogen
Nitrogen
Argon/methane 5%
Nitrogen
Note:
ArMe makeup provides
maximum Dynamic Range
Nitrogen makeup provides
maximum Sensitivity
Flame
ionization
Hydrogen
Helium
Nitrogen
Nitrogen
Nitrogen
Nitrogen
Helium
Helium
Helium
Hydrogen* and air for detector
Flame
photometric
Hydrogen*
Helium
Nitrogen
Argon
Nitrogen
Nitrogen
Nitrogen
Nitrogen
None
Hydrogen* and air for detector
Nitrogen
phosphorous
Helium
Nitrogen
Nitrogen
Nitrogen
Helium
Helium
Hydrogen* and air for detector
Thermal
conductivity
Hydrogen*
Helium
Nitrogen
Must be same as
carrier and
reference
Must be same as
carrier and reference
Reference must be same as
carrier and makeup
* See "Considerations For Hydrogen Carrier Gas" in this document.
