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| Titel |
Laser spectrometer for CO2 clumped isotope analysis |
| VerfasserIn |
Ivan Prokhorov, Tobias Kluge, Christof Janssen |
| Konferenz |
EGU General Assembly 2017
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| Medientyp |
Artikel
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| Sprache |
en
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 19 (2017) |
| Datensatznummer |
250141524
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| Publikation (Nr.) |
 EGU/EGU2017-5045.pdf |
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| Zusammenfassung |
| Carbon dioxide clumped isotope thermometry has proven to be a reliable method for
biogeochemical and atmospheric research. We present a new laser spectroscopic
instrument for doubly-substituted isotopologues analysis. In contrast to a conventional
isotope ratio mass spectrometry (IRMS), tunable laser direct absorption spectroscopy
(TLDAS) has the advantage of isotopologue-specific determination free of isobaric
interferences.
Tunable infrared laser based spectrometer for clumped isotope analysis is being
developed in collaboration between Heidelberg University, Germany, and LERMA-IPSL,
CNRS, France. The instrument employs two continuous intraband cascade lasers (ICL)
tuned at 4439 and 4329 nm. The spectral windows covered by the lasers contain
absorption lines of the six most abundant CO2 isotopologues, including the two
doubly substituted species 16O13C18O and 16O13C17O, and all singly substituted
isotopologues with 13C, 18O and 17O. A Herriott-type multi-pass cell provides two different
absorption pathlengths to compensate the abundance difference between singly-
and doubly-substituted isotopologues. We have reached the sub-permill precision
required for clumped isotope measurements within the integration time of several
seconds.
The test version of the instrument demonstrates a performance comparable to state of the
art IRMS. We highlight the following features of the instrument that are strong advantages
compared to conventional mass spectrometry: measurement cycle in the minute range,
simplified sample preparation routine, table-top layout with a potential for in-situ
applications. |
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