Inter-laboratory re-determination of the atmospheric 22Ne/20Ne

Györe, D. , Sumino, H., Yang, I., Palcsu, L., László, E., Bishop, M. C., Mukhopadhyay, S. and Stuart, F. M. (2024) Inter-laboratory re-determination of the atmospheric 22Ne/20Ne. Chemical Geology, 645, 121900. (doi: 10.1016/j.chemgeo.2023.121900)

Abstract

Accurate knowledge of the Ne isotopic composition of air is essential for planetary science. While the uncertainty of the noble gas isotopic composition of air has been drastically reduced to the level of ∼0.1% in the last few years thanks to modern techniques, the most widely accepted value of the 22Ne/20Ne ratio of air (0.102 ± 0.0008, Eberhardt et al., 1965) has an uncertainty of ±0.78% (1σ). Here we present the first multi-laboratory re-determination of the atmospheric 22Ne/20Ne. An artificial, high purity mixture of 20Ne and 22Ne was prepared and the 22Ne/20Ne (0.11888 ± 0.00001, 1σ) and 20Ne/22Ne (8.4118 ± 0.0007, 1σ) determined gravimetrically. This gas was used to determine the mass fractionation of five mass spectrometers allowing the air 22Ne/20Ne to be determined (n = 234 analyses). Each laboratory sampled their own local air, used a different gas preparation system and analysis procedure as well as doing their own expansion of the high-pressure artificial Ne gas. Individual air 22Ne/20Ne determinations have uncertainties in the range of 0.01–0.08%. The overall reproducibility of the calculated 22Ne/20Ne of air between the laboratories shows no overdispersion with respect to the individual uncertainties. We report a global value for the atmospheric 22Ne/20Ne of 0.10196 ± 0.00007 (0.07%, 1σ), equivalent of 20Ne/22Ne of 9.808 ± 0.007. This is almost identical to the Eberhardt et al. (1965) value although its uncertainty shows a 12 times reduction. Our study did not verify any of the other previous determinations of atmospheric 22Ne/20Ne. This highly accurate and precise atmospheric 22Ne/20Ne value provides a new reference for atmospheric 21Ne/20Ne determinations and we recalculate (21Ne/20Ne)air of five recent determinations. While this exercise resulted in no significant change to the absolute values, it gives more confidence with respect to the correctness of (21Ne/20Ne)air. We suggest that the revised value for atmospheric 22Ne/20Ne be used routinely in all geoscience applications.

• Item Type: Articles
• Additional Information: This work carried out by ATOMKI was co-supported by the European Union and the State of Hungary, co-financed by the European Regional Development Fund in the project of GINOP509 2.3.2-15-2016-00009 ‘ICER’. E.L. was additionally financed by the János Bolyai Research Scholarship of the Hungarian Academy of Sciences BO/00281/21/10.
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Gyore, Dr Domokos and Stuart, Professor Fin

Creator Roles

Gyore, D.: Conceptualization, Formal analysis, Methodology, Writing – original draft, Writing – review and editing, Data curation, Investigation, Visualization
Stuart, F.: Data curation, Methodology, Writing – review and editing

• Authors: Györe, D., Sumino, H., Yang, I., Palcsu, L., László, E., Bishop, M. C., Mukhopadhyay, S., and Stuart, F. M.
• Subjects: Q Science > QE Geology
• College/School: College of Science and Engineering > Scottish Universities Environmental Research Centre
• Journal Name: Chemical Geology
• Publisher: Elsevier
• ISSN: 0009-2541
• Copyright Holders: Copyright: © 2023 The Authors
• First Published: First published in Chemical Geology 645: 121900
• Publisher Policy: Reproduced under a Creative Commons licence