Good morning, I have spent two weeks with the oxygen concentration at 1.9% and the nitrogen at 7%, I would like to know how I can lower them. We have a GC/MS, 7890B/5977B.
Good morning, I have spent two weeks with the oxygen concentration at 1.9% and the nitrogen at 7%, I would like to know how I can lower them. We have a GC/MS, 7890B/5977B.
You can use canned air duster without bitterant, which may be a bit more difficult to find. The bitterant is an added chemical to stop huffing the gas to get high.
In Manual Tune
Set all three ions to the primary ion of the air duster chemical. (e.g. 65,65,65)
Repeat Profile with the filament on and the PFTBA off
Set the scale to manual and increase it so that the background is small
Be patient! From the inlet end it can take a minute or two to see any air duster ions
Start at the MS, working your way backwards through the system
MS analyzer door
PFTBA valve
Vent valve
Transferline nut in the GC oven
Purged Ultimate Union in oven if installed
Inlet column nut
Most leaks can be fixed by venting and reinstalling the column into the MS with a new ferrule and wiping off the analyzer door O ring with a lint-free cloth before pumping down.
Always use the 85% Polyimide/15% Graphite ferrules on the inlet and transferline on GCMS systems.
