Investigating Baseline Issues; Drifting Baseline - Thermo Scientific TSQ 8000 Evo User Manual

Investigating Baseline Issues

Behavior Characteristic

Drifting Baseline

General
Falling
Rising
Abnormal rise in
baseline when oven
temperature is high
Thermo Scientific
Cause
Stationary phase has
accumulated in column
Chromatographic baseline
is high
Carrier gas pressure is too
low
Carrier gas flow is drifting
Impurities have
accumulated in column
Carrier gas leak in the
system
Column is baking out
Impurities have
accumulated in column
Impurities have
accumulated in column
Investigating Baseline Issues
Remedy
Replace the column or cut off the end of
the column.
Replace the column or cut off the end of
the column.
Check for leaks in injector or flow path.
Replace the carrier gas cylinder if it is
empty or low. Increase the pressure if
maximum injector pressure in method is
greater than carrier line pressure set by
regulator. Make sure the vacuum
compensation is on.
Check for leaks in injector or flow path.
Check the carrier gas tank.
Run solvent blank to remove impieties.
If impurities persistent after multiple
solvent blanks: Inject solvent from a
different source. Change syringe, liner
and septum. Clean injector. Check
impurity levels in your gas. Use the
correct gas purity and filter.
Perform a leak test and tighten the
connections to the carrier gas line if leak
is found.
Wait for the column to stabilize.
Check impurity levels in the gas source.
Use correct gas purity.
Recondition or replace the column.
TSQ 8000 Evo User Guide
7
Troubleshooting
119