ISQ User Guide - Write Frame of Mind

Table 3. Troubleshooting Peak Issues in Your Data, continued
Behavior Cause Characteristic Remedy
Unresolved Peaks General
GC oven is too cold
Column has deteriorated
Column is not far enough into the
transfer line
8 Troubleshooting
Investigating Peak Issues
The GC oven is not ramped to high enough
temperature. Extend upper oven temperature.
The GC column needs to be replaced or does not have
the appropriate stationary phase for your application.
Change GC column.
The GC column does not extend into the ISQ source.
Use the column measuring tool to confirm the column
length. If the end of the column is inside the transfer
line, an excessive amount of GC effluent will contact
the inside wall.
Ion source and/or transfer line are not hot enough.
Increase the transfer line temperature. It should be at
Transfer line is too cold
least as hot as the highest GC oven temperature.
Then try increasing the ion source temperature.
Sample analyte is absorbing in the GC injector. Clean
Injector is too active
and deactivate the injection liner. You can also try
liners made of different materials.
Injection technique is not
Choose a more appropriate injection technique.
adequate
Incorrect column flow rate Make sure the vacuum compensation is turned on.
Thermo Scientific ISQ User Guide 95