High CO2, N2 and O2

[lemontree0815]

Recently, we changed the EI source on our GC/MS system. We did an autotune and everything looked fine. We were able to run some samples on it and get good results. But when we tune the GC/MS today, we found high N2 18.1%, high O2 3.8% and 14% CO2. Is this an air leak? The N2 and O2 ratio is about 5 and I never see CO2 so high before.

[James_Ball]

Check to see if the column nut is loose. If you install a new ferrule sometimes the graphite/vespel ferrules will shrink when heated and after a few oven cycles you will get a leak where the column enters the analyzer.

[loopylinda]

Hi there it's just a leak most likely at the column transfer line interface tighten it a bit and all should be ok...