Comparative isotopic measurements on xenon and krypton

Highly accurate isotopic measurements of the noble gases krypton and xenon have been performed at the Institute for Reference Materials and Measurements. Two mass spectrometers based on different physical principles (quadrupole, sector field) were used to perform comparative isotopic measurements on commercial xenon and krypton gases. The measurement processes are described in detail and subsequently the obtained isotope ratios are compared with each other, focusing on the uncertainties achieved. Finally, the necessity and potential application of ultra-accurate measurements of the isotopic composition of noble gases to detect their release from anthropogenic sources and the subsequent dilution in atmospheric noble gases are taken into consideration.