It's mainly the nitrogen, or the nitrogen and oxygen, from the air that
reacts in the source to give N2O and NO2, masses 44 and 46. If your
were to run air instead of breath, you'll see those same peaks, though
the CO2 peak will be very small. Depending on your conditions, you may
separate out other gases that react in the source to give an interfering
signal, e.g. oxygen, which tends to run close to or with the nitrogen,
and methane--which I hope you don't see in any breath samples.
Shaji Chacko wrote:
> Hello all,
> When CO2 samples are analyzed from breath tubes on the breath Bench
> (Gas bench-2), we always see some peaks (predominantly with 45 &46 ions)
> before the CO2 peaks but well separated from the CO2 peaks. I would
> like to
> have some information and explanation about it.
> Thanks in advance.
> SHAJI K CHACKO MS
> Childrens' Nutrition Research Center
> Baylor College of Medicine
> 1100 Bates, Houston
> TEXAS-77030, USA
> Tel - 713-798-7102
> Fax- 713-798-7119