 |
| Titel |
The new high-resolution IRMS MAT253 ULTRA at Utrecht University |
| VerfasserIn |
Thomas Röckmann, Magdalena Hofmann, Dipayan Paul, Elena Popa, Getachew Adnew |
| Konferenz |
EGU General Assembly 2017
|
| Medientyp |
Artikel
|
| Sprache |
en
|
| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 19 (2017) |
| Datensatznummer |
250146220
|
| Publikation (Nr.) |
 EGU/EGU2017-10231.pdf |
|
|
|
|
|
| Zusammenfassung |
| In 2016, the new high-resolution, multi-collector isotope ratio mass spectrometer MAT253
ULTRA [1] was installed at Utrecht University. This instrument is designed to reach a mass
resolving power of 20,000 to 40,000 (M/ΔM). The ion currents are detected with a variable
multi-collector unit that allows to register up to 9 ion currents simultaneously with Faraday
cups and ion counters. The width of the entrance slit can be varied between 5 and 250μm so
that the instrument can be operated under low, medium and high mass resolution, and an
optimum balance between resolution and sensitivity can be selected for the respective
applications.
The central field of application of the new IRMS at Utrecht University is the measurement
of multiply substituted isotopologues (clumped isotopes) in atmospheric trace compounds
(e.g. 13CDH3, 13C18O16O, 18O18O, 15N14N18O) [1-7]. It is known from thermodynamics
that the zero point energy of a chemical bond usually decreases when multiple heavy isotopes
clump together in a molecule, and this effect depends on temperature [7]. Therefore, the
abundance of clumped isotopes can be used as temperature indicator under thermodynamical
equilibrium conditions. However, in the atmosphere, many reactions are controlled
kinetically. It has been shown recently for a few examples that negative clumping signatures
(anti-clumping) can be produced under non-equilibrium conditions [3,4]. In addition, based
on purely statistical reasons, anti-clumping signatures will be produced in any molecule
that contains indistinguishable atoms, which originate from isotopically distinct
reservoir [5,6]. Thus, the investigation of multiply substituted isotopologues is
expected to generate novel isotope signatures that can complement conventional stable
isotope analysis in atmospheric science. We will present data on the performance of
the MAT 253 ULTRA instrument and first scientific applications to atmospheric
research.
1. Eiler, J.M., et al., A high-resolution gas-source isotope ratio mass spectrometer, Int. J.
Mass Spect., 2013. 335: 45– 56.
2. Young, E.D., et al., A large-radius high-mass-resolution multiple-collector isotope ratio
mass spectrometer for analysis of rare isotopologues of O2, N2, CH4 and other gases, Int. J.
Mass Spect., 2016. 401: 1-10.
3. Wang, D.T., et al., Nonequilibrium clumped isotope signals in microbial methane,
Science, 2015. 348: 428-431.
4. Yeung, L.Y., et al., Biological signatures in clumped isotopes of O2, Science, 2015.
348: 431-434.
5. Yeung, L.Y., Combinatorial effects on clumped isotopes and their significance in
biogeochemistry, Geochim. Cosmochim. Act., 2016: doi:10.1016/j.gca.2015.09.020.
6. Röckmann, T., et al., Statistical clumped isotope signatures Scientific reports, 2016. 6:
31947; doi: 10.1038/srep31947.
7. Wang, Z.G., et al., Equilibrium thermodynamics of multiply substituted isotopologues
of molecular gases, Geochim. Cosmochim. Act., 2004. 68: 4779-4797. |
|
|
|
|
|
|