Publication Date:
2022-06-08
Description:
A continuous-flow GC/IRMS technique has been developed to analyse δ15N values for molecular nitrogen
in gas samples. This method provides reliable results with accuracy better than 0.15‰and reproducibility
(1σ) within ±0.1‰ for volumes of N2 between 1.35 (about 56 nmol) and 48.9μL (about 2μmol).
The method was tested on magmatic and hydrothermal gases as well as on natural gas samples collected
from various sites. Since the analysis of nitrogen isotope composition may be prone to atmospheric contamination
mainly in samples with low N2 concentration, we set the instrument to determine also N2 and
36Ar contents in a single run. In fact, based on the simultaneously determined N2/36Ar ratios and assuming
that 36Ar content in crustal and mantle-derived fluids is negligible with respect to 36Ar concentration in
the atmosphere, for each sample, the degree of atmospheric contamination can be accurately evaluated.
Therefore, the measured δ15N values can be properly corrected for air contamination.
Description:
Published
Description:
141–155
Description:
2.4. TTC - Laboratori di geochimica dei fluidi
Description:
JCR Journal
Description:
reserved
Keywords:
Argon-36
;
isotope measurement and technique
;
nitrogen-15
;
volcanic and hydrothermal gas
;
04. Solid Earth::04.04. Geology::04.04.12. Fluid Geochemistry
;
04. Solid Earth::04.07. Tectonophysics::04.07.06. Subduction related processes
;
04. Solid Earth::04.08. Volcanology::04.08.01. Gases
;
04. Solid Earth::04.08. Volcanology::04.08.07. Instruments and techniques
Repository Name:
Istituto Nazionale di Geofisica e Vulcanologia (INGV)
Type:
article
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