Progress of Cryogenics and Isotopes Separation , ISSN: 1582-2575
2012, Volume 15, Issue 1

Experimental Evidences of the Influence of Nitrogen Gas on the Trimer Ions in Low Resolution Mass Spectrometry of Hydrogen Isotopes

Abstract

This paper presents experimental results regarding the behaviour of triatomic (trimer) ions formed in the electron impact ion source of a mass spectrometer in the presence of high concentrations of nitrogen gas. These results were obtained during an experimental work performed in order to find solutions to correct the total ion currents (measured at masses of interest) that are affected by isobaric interferences in low resolution mass spectrometry of hydrogen isotopes. A commercial quadrupole mass spectrometer of unit resolution, equipped with an electron impact ion source, was usedto analysehigh purity H₂ and D₂ and several H₂/N₂ and D₂/N₂ mixtures (of different concentrations).

The results show a high influence of nitrogen gas on trimer ions, and this influence could be used to develop new procedures for hydrogen isotopes measurement by low resolution mass spectrometry.