Hi everyone. Posting on behalf of someone else.
My colleague is using an HP 6890 GC with a 5973 mass selective detector. We're observing a mysterious oxygen peak at m/z 32. I would normally suspect it's caused by an air leak, but there is no accompanying peak at m/z 28. The helium gas tank and the gas purifier have been replaced, and all fittings have been checked for potential leaks (although again there's no m/z 28). Does anybody have any idea where this peak may be coming from?