Every Second Injection

[GC_Man83]

Hi Folks,

I am running an established method for OVI analysis and am noticing a "bonus" peak on every second injection in my sequence. Any thoughts?

[JMcK]

Could this be carryover? It's a little hard to diagnose with the amount of data you provided. If you have 3 injections do you see the peak in the second and third injection. If you inject a blank immediately after the sample is the mysterious peak there? What happens if you extend the run?

[GC_Man83]

Its a very sharp peak which makes me think it wouldn't be carry over

[chromatographer1]

Have you observed your autosampler injecting? See anything unusual?

Can you show us a chromatogram, or list the method parameters of the ALS?

Your column description, the type of inlet liner, the installation parameters of the column you used and have checked are all useful pieces of information.

best wishes,

Rod

[Bigbear]

When was the last time injector maintenance was done?