Dear Willi and others,

the post scriptum in your posting triggered my interest since we are 
apparently suffering from CO+ peaks where no CO2 should be 
present.
We are measuring N2 at fairly low concentrations (1000ppm) with 
high O2 (50%) but N2O, CO2 etc should be eliminated by our 
chemical trap/LN2 trap sequence in a GasBench-like setup.
Do I correclty gather from your posting that CO2 (and CO?) could be 
formed although no C is present in the sample?
Sounds mysterious to be but could explain our problems (which also 
dissapear when removing O2 from the sample).

Thanks,

Jens