A new portable sampler of atmospheric methane for radiocarbon measurements
File(s)
Published version
Author(s)
Type
Journal Article
Abstract
Radiocarbon (14C) is an optimal tracer of methane emissions, as 14C measurements enable distinguishing between fossil methane and biogenic methane (CH4). However, 14C measurements in atmospheric methane are still rare, mainly because of the technical challenge of collecting enough carbon for 14C analysis from ambient air samples. In this study, we address this challenge by advancing the system in Zazzeri et al. (2021) into a much more compact and portable sampler and by coupling the sampler with the MICADAS (MIni CArbon DAting System) accelerator mass spectrometry (AMS) system at ETH Zurich, using a gas interface.
Here, we present the new sampler setup, the assessment of the system contamination and a first inter-laboratory comparison with LARA (Laboratory for the Analysis of Radiocarbon with AMS) at the University of Bern.
With our sampling line, we achieved a very low blank, 0.7 µgC compared to 5.5 µgC in Zazzeri et al. (2021), and a sample precision of 0.9 %, comparable with other measurement techniques for 14CH4, while reducing the sample size to 60 L of air. We show that this technique, with further improvements, will enable routine 14CH4 measurements in the field for an improved understanding of CH4 sources.
Here, we present the new sampler setup, the assessment of the system contamination and a first inter-laboratory comparison with LARA (Laboratory for the Analysis of Radiocarbon with AMS) at the University of Bern.
With our sampling line, we achieved a very low blank, 0.7 µgC compared to 5.5 µgC in Zazzeri et al. (2021), and a sample precision of 0.9 %, comparable with other measurement techniques for 14CH4, while reducing the sample size to 60 L of air. We show that this technique, with further improvements, will enable routine 14CH4 measurements in the field for an improved understanding of CH4 sources.
Date Issued
2025-01-20
Date Acceptance
2024-11-03
Citation
Atmospheric Measurement Techniques, 2025, 18 (2), pp.319-325
ISSN
1867-1381
Publisher
Copernicus Publications
Start Page
319
End Page
325
Journal / Book Title
Atmospheric Measurement Techniques
Volume
18
Issue
2
Copyright Statement
© Author(s) 2025. This work is distributed under the Creative Commons Attribution 4.0 License.
License URL
Subjects
C-14
Meteorology & Atmospheric Sciences
Physical Sciences
Science & Technology
Publication Status
Published
Date Publish Online
2025-01-20