Problems with oxygen, in GC/MS

I had this similar issue with our GCMS after replacing a helium purifier. The best way to reduce the oxygen and nitrogen showing in your tunes is to run approximately 20-40 blanks depending on your cycle time. I have about a 30 minute cycle time and finally got my tunes back to normal after 25 blanks. I would also check for leaks and make sure the screws fastening your column in the oven aren't lose. Give it time to purge the column, and if this doesn't work I recommend a steam clean. 

Good morning, thank you very much for your indications, we are going to check for leaks, so as not to make injections before lowering N and O. The equipment has been stabilizing for two weeks, and the parameters remain stagnant at the indicated values.

Good morning, thank you very much for your indications, we are going to check for leaks, so as not to make injections before lowering N and O. The equipment has been stabilizing for two weeks, and the parameters remain stagnant at the indicated values.