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Titel |
Calibrated high-precision ¹⁷O-excess measurements using cavity ring-down spectroscopy with laser-current-tuned cavity resonance |
VerfasserIn |
E. J. Steig, V. Gkinis, A. J. Schauer, S. W. Schoenemann, K. Samek, J. Hoffnagle, K. J. Dennis, S. M. Tan |
Medientyp |
Artikel
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Sprache |
Englisch
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ISSN |
1867-1381
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Digitales Dokument |
URL |
Erschienen |
In: Atmospheric Measurement Techniques ; 7, no. 8 ; Nr. 7, no. 8 (2014-08-08), S.2421-2435 |
Datensatznummer |
250115866
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Publikation (Nr.) |
copernicus.org/amt-7-2421-2014.pdf |
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Zusammenfassung |
High-precision analysis of the 17O / 16O
isotope ratio in water and water vapor is of interest in
hydrological, paleoclimate, and atmospheric science applications.
Of specific interest is the parameter
17O excess (Δ17O),
a measure of the deviation from a~linear relationship between
17O / 16O and
18O / 16O ratios. Conventional analyses of
Δ17O of water are obtained by fluorination of
H2O to O2 that is analyzed by dual-inlet isotope
ratio mass spectrometry (IRMS). We describe a new laser spectroscopy
instrument for high-precision Δ17O
measurements. The new instrument uses cavity ring-down spectroscopy
(CRDS) with laser-current-tuned cavity resonance to achieve reduced measurement
drift compared with previous-generation instruments. Liquid water
and water-vapor samples can be analyzed with a better than 8 per meg
precision for Δ17O using integration times of
less than 30 min. Calibration with respect to accepted water
standards demonstrates that both the precision and the accuracy of Δ17O
are competitive with conventional IRMS methods. The new instrument also
achieves simultaneous analysis of δ18O,
Δ17O and δD with precision of < 0.03‰,
< 0.02 and < 0.2‰, respectively, based on repeated
calibrated measurements. |
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