Agilent Technologies 5975T LTM GC/MSD, Troubleshooting And Maintenance Manual

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52 Troubleshooting and Maintenance Guide
3
Chromatographic Symptoms
• Building heating/cooling system
• Other electronic interferences in the lab
Spikes are isolated baseline disturbances, usually appearing as
sudden (and large) upscale movements. If accompanied by
noise, resolve the noise problem first since spiking may
disappear at the same time.
• Check for a contaminated ion source.
• Check for the correct jet.
Retention times for all peaks drift – shorter
• Column has been shortened
• Initial column temperature was increased
• Column is getting old
Retention times for all peaks drift – longer
• Column flow has been reduced
• Initial column temperature was decreased
• Active sites in the sample path
• Leaks in the GC inlet*
* This could cause a fault condition in the GC that would prevent
the GC from operating.
Figure 3 Random spiking