I have noticed that most SAM testbed datasets do not contain any m/z=4, but a lot of m/z=18. Furthermore, some commercial datasets contain far more m/z=14 (nitrogen?), 16 (oxygen?) or 18 (argon?) than m/z=4 (helium).
Could there be a mix-up of carrier gases?
Andreas
Hi @akrueger67,
The SAM testbed always uses helium as the carrier gas. It may be the case that m/z=4.0 gets saturated for the mass spectrometer, which will cause it to read as 0 for the abundance.
For the commercial samples, samples known to be using a carrier gas other than helium have been excluded from the primary competition dataset and are instead included in the supplemental dataset. However, as with any real world data, there may be noise in the data.