GC Instrument Blank
If you observe unexplained or unidentified peaks appearing in your chromatogram and wish to determine whether these peaks are originating from the GC hardware itself or from the sample or its pathway, you can run a GC instrument blank for clarification.
It is different from injecting an n-hexane blank sample, as the GC blank method ensures that no eluate from the LC system is introduced.
A good example of an instrument blank looks like the chromatogram below:
