Deconvolution and compensation of mass spectrometric overlap interferences with the miniRUEDI portable mass spectrometer

Abstract

The miniRUEDI is a portable mass spectrometer system designed for on-site analysis of gases in the environment during field work and at remote locations. For many gas species (e.g., He, Ar, Kr, N-2 , O-2 , CO2) the ion-current peak-heights measured with the mass spectrometer can usually be calibrated in terms of the partial pressures by simple peak-height comparison relative to a gas standard with well known partial pressures. However, depending on the composition of the analysed gases, the ion currents measured at certain m/z ratios may result from overlapping signals of multiple species (for example CH4, O-2 and N-2 at m/z = 15 and 16; or Ne, Ar and H2O at m/z = 20 ). Here, we present a method extension to the existing miniRUEDI peak-height comparison in order to resolve such overlap interferences: We developed and tested a data processing procedure for accurate deconvolution and compensation of such mass-spectrometric overlap interferences. The method was incorporated into the miniRUEDI open-source software (ruediPy). The method substantially improves the analytical accuracy in situations where mass-spectrometric interferences cannot be avoided. (C) 2020 The Author(s). Published by Elsevier B.V.