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APPENDIX B
GC/MS TROUBLESHOOTING QUICK
REFERENCE
This section is designed to assist in troubleshooting system problems. It is not
meant to replace systematic troubleshooting and routine maintenance. A
systematic reverse order approach to problems is always better. Keeping this
in mind, the commonly seen problems, possible causes, and suggested
treatment are listed in this appendix. Appendix C contains a list of common
background contaminants.
B.1 GC INJECTOR PROBLEMS
Problem 1: Peaks broaden and tail.
Cause a: Poor column installation causing dead volume in the injector.
Treatment: Reinstall column in injector. Check seal at ferrule.
Check insertion depth. Ensure a good column cut.
Cause b: Solvent flashing in hot injector.
Treatment: Reduce injection speed on hot injectors and if possible reduce injector temperature. If you are using
sandwich injection, reduce solvent plug to 0.5 ml.
Cause c: Incorrect injector temperature control.
Treatment: Typically set injector temperature at 20 C lower than
solvent boiling point and keep column at solvent
GC/MS: A Practical User’s Guide, Second Edition. By Marvin C. McMaster
Copyright # 2008 John Wiley & Sons, Inc.
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