Thermo Scientific TRACE GC Ultra Maintenance And Troubleshooting Manual page 400

Chapter 19
Analytical Troubleshooting
Behavior Characteristics
Poor with normal
sensitivity retention time
Decreasing
Increasing
Retention
times
Low
reproducibility
400
Cause
Leaks in the GC carrier gas
line.
Syringe leaks during
injection
Split injection temperature
too low
Stationary phase
deteriorated by oxygen and/
or water
Stationary phase loss due to
column bleeding
Increasing carrier leakage
Carrier gas supply running
out
Drifting or unstable
pneumatic controller
Poor injection technique
Sample size is too large
Unstable column
temperature
Remedy
Run a leak test and correct leaks.
Replace syringe or piston seals,
if applicable.
Increase the temperature of the
injector.
Use a carrier gas free of oxygen
and water.
Reduce the column temperature.
Check the septum and column
connections.
Replace the bottle.
Monitor the column pressure or
flow.
Check and replace the controller
if necessary.
Start the run at consistent time
after injection.
Reduce the injected amount and/
or volume.
Check the main oven door and
cooling flap.
Monitor the column temperature.
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