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| Titel |
High-accuracy measurements of N2O concentration and isotopic composition of low and high concentration samples with small volume injections using Cavity Ring-Down Spectroscopy |
| VerfasserIn |
Nabil Saad, Melissa Palmer, Kuan Huang |
| Konferenz |
EGU General Assembly 2015
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 17 (2015) |
| Datensatznummer |
250108228
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| Publikation (Nr.) |
 EGU/EGU2015-7972.pdf |
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| Zusammenfassung |
| Nitrous oxide (N$_{2}$O) gas is among the major contributors to global
warming and ozone depletion in stratosphere. Quantitative estimate of
N$_{2}$O production in various pathways and N$_{2}$O fluxes across different
reservoirs is the key to understanding the role of N$_{2}$O in the global
change. To achieve this goal, accurate and concurrent measurement of both
N$_{2}$O concentration ([N$_{2}$O]) and its associated isotopic ratios
($\delta ^{15}{\rm N}^{\alpha }$, $\delta ^{15}{\rm
N}^{\beta }$ {\&} $\delta ^{18}{\rm O}$) is desired.
Recent developments in Cavity Ring-Down Spectroscopy (CRDS) have enabled
high-precision measurements of [N$_{2}$O] and Site-Preference-$\delta
^{15}{\rm N}$ (SP-$\delta ^{15}{\rm N})$ and $\delta
^{ 18}{\rm O}$ of a continuous gas flow. However, many N$_{2}$O
samples are discrete with limited volume ($$ 2 ppm), and are not suitable for direct continuous measurements by
CRDS. Here we present results of a small sample introduction and handling
device, labelled as Small Sample Isotope Module (SSIM), coupled to and
automatically coordinated with a Picarro isotopic N$_{2}$O CRDS analyzer to
handle and measure high concentration and/or small volume samples. The SSIM
requires 20 ml of sample volume per analysis at STP, and transfers the
sample to the CRDS for high-precision concentration and isotope ratio
measurements. When the injected sample is $ |
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