Test of potential mass to charge 30 interferences from O2

Abstract

Molecular oxygen (O2) has been documented to ionize partially to NO+ in mass spectrometer sources, generating a signal that overlaps with that of 15N2 (mass-to-charge of 30). Here, we tested whether O2 needs to be specifically removed from the sample streams of the Membrane Inlet Mass Spectrometer and the Isotope Ratio Mass Spectrometer in order to properly quantitate 15N2 atom% at pertinent concentrations. Sample streams with and without O2 yielded similar signals, suggesting that O2 does not interfere with the 15N2 atom% measurements in the experimental range with the given instruments.

For a complete list of measurements, refer to the full dataset description in the supplemental file 'Dataset_description.pdf'. The most current version of this dataset is available at: https://www.bco-dmo.org/dataset/778083