A new portable sampler of atmospheric methane for radiocarbon measurements
<p>Radiocarbon (<span class="inline-formula"><sup>14</sup></span>C) is an optimal tracer of methane emissions, as <span class="inline-formula"><sup>14</sup></span>C measurements enable distinguishing between fossil methane and...
Saved in:
| Main Authors: | , , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2025-01-01
|
| Series: | Atmospheric Measurement Techniques |
| Online Access: | https://amt.copernicus.org/articles/18/319/2025/amt-18-319-2025.pdf |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| Summary: | <p>Radiocarbon (<span class="inline-formula"><sup>14</sup></span>C) is an optimal tracer of methane emissions, as <span class="inline-formula"><sup>14</sup></span>C measurements enable distinguishing between fossil methane and biogenic methane (CH<span class="inline-formula"><sub>4</sub></span>). However, <span class="inline-formula"><sup>14</sup></span>C measurements in atmospheric methane are still rare, mainly because of the technical challenge of collecting enough carbon for <span class="inline-formula"><sup>14</sup></span>C 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.</p>
<p>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.</p>
<p>With our sampling line, we achieved a very low blank, 0.7 <span class="inline-formula">µgC</span> compared to 5.5 <span class="inline-formula">µgC</span> in Zazzeri et al. (2021), and a sample precision of 0.9 %, comparable with other measurement techniques for <span class="inline-formula"><sup>14</sup></span>CH<span class="inline-formula"><sub>4</sub></span>, while reducing the sample size to 60 L of air. We show that this technique, with further improvements, will enable routine <span class="inline-formula"><sup>14</sup></span>CH<span class="inline-formula"><sub>4</sub></span> measurements in the field for an improved understanding of CH<span class="inline-formula"><sub>4</sub></span> sources.</p> |
|---|---|
| ISSN: | 1867-1381 1867-8548 |