This Information Applies To: Agilent GC Systems with Split/Splitless Inlet (S/SL)
The Split/Splitless Inlet (S/SL) can accumulate contaminants when high boiling point and/or high molecular weight compounds are present in the injected sample. Often these compounds are present from the sample matrix. The accumulated contamination is not effectively removed using the analysis method parameters. These accumulated contaminants may appear in the chromatogram as ghost or artifact peaks. They can also be retained on the inside surface of the inlet liner, gold seal, or inlet weldment increasingly affecting the performance of the inlet over time.
During the S/SL inlet bake-out procedure (Steps 1 to 7), high boiling point and/or high molecular weight compounds are subjected to higher inlet temperature and flow in an attempt to vaporize and remove these contaminants. The contaminant molecules, if vaporized, are purged out of the inlet under high split flow to the split vent. A bake-out of column and detector are in the subsequent steps (Steps 8 to 12) of the procedure.
Steps to Follow
Warning: The oven, inlet, and detector may be hot enough to cause burns. Wear heat-resistant gloves to protect your hands.
Caution: Heating the oven/column up before adequate purging time with carrier gas could damage the column since residual oxygen in the carrier gas, when heated will damage the stationary phase of the column.
Do not set the inlet, oven/column, or detector temperature above the column being used manufacturers maximum isothermal operating temperature.
If this S/SL bake-out procedure does not restore the inlet performance, replacement of the inlet liner and gold seal will likely be required as the accumulated contamination has not been totally removed. This would be typical of samples with matrix compounds that are nonvolatile but soluble in the injected sample solvent.
Learn how to effectively troubleshoot your GC Split/Splitless Inlet:
GC-7890-2245s - Agilent 7890 Series GC: Split/Splitless Inlet Troubleshooting e-learning course available from Agilent education