Maintenance; To Clean The Ci Ion Source - HP 5973 MSD Hardware Manual

To clean the CI ion source

The CI ion source has slightly different cleaning requirements than the standard EI
ion source. See the procedure in the HP 5973 MSD Reference Collection CD-ROM.
Frequency of cleaning
Because the CI ion source operates at much higher pressures than the EI ion
source, it will probably require more frequent cleaning than the EI ion source.
Cleaning of the source is not a scheduled, periodic maintenance procedure. The
source should be cleaned whenever there are performance anomalies that are
associated with a dirty ion source. See the Troubleshooting chapter for symptoms
that indicate a dirty ion source. Visual appearance is not an accurate guide
to cleanliness of the CI ion source. The CI ion source can show little or
no discoloration yet still need cleaning. Let analytical performance be your
guide.
Cleaning procedure
Cleaning the CI ion source is very similar to cleaning the EI ion source. Use the
cleaning procedure in the chapter Maintaining the MSD of the HP 5973 MSD
Hardware Manual with the following exceptions:
• The CI ion source may not look dirty but deposits left by chemical ionization are
• Use a round wooden toothpick to gently clean out the electron entrance hole in
• Do not use halogenated solvents, and use hexane for the final rinse.
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The HP 5973 MSD Reference Collection CD-ROM illustrates using a small drill bit to clean
the small holes in the ion source body and drawout plate. This is not recommended. Use
the tip of a clean, round toothpick instead.
See Also
Refer to the MSD Reference Collection CD-ROM for video demonstrations of ion
source cleaning and other maintenance procedures.
C A U T I O N Do not use any halogenated solvents to clean the CI ion source.
very difficult to remove. Clean the CI ion source thoroughly.
the source body and the ion exit hole in the drawout plate.

 Maintenance

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