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| Titel |
Isotope pattern deconvolution as rising tool for isotope tracer studies in environmental research |
| VerfasserIn |
Johanna Irrgeher, Andreas Zitek, Thomas Prohaska |
| Konferenz |
EGU General Assembly 2014
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 16 (2014) |
| Datensatznummer |
250088334
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| Publikation (Nr.) |
 EGU/EGU2014-2431.pdf |
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| Zusammenfassung |
| During the last decade stable isotope tracers have emerged as versatile tool in ecological
research. Besides ‘intrinsic’ isotope tracers caused by the natural variation of isotopes, the
intentional introduction of ‘extrinsic’ enriched stable isotope tracers into biological
systems has gained significant interest. Hereby the induced change in the natural
isotopic composition of an element allows amongst others for studying the fate and
fluxes of metals, trace elements and species in organisms or provides an intrinsic
marker or tag of particular biological samples. Due to the shoreless potential of this
methodology, the number of publications dealing with applications of isotope (double)
spikes as tracers to address research questions in ‘real world systems’ is constantly
increasing.
However, some isotope systems like the natural Sr isotopic system, although potentially
very powerful for this type of application, are still rarely used, mainly because their adequate
measurement/determination poses major analytical challenges; as e.g. Sr is available in
significant amounts in natural samples. In addition, biological systems underlie complex
processes such as metabolism, adsorption/desorption or oxidation/reduction. As a
consequence, classic evaluation approaches such as the isotope dilution mass spectrometry
equation are often not applicable because of the unknown amount of tracer finally present in
the sample.
Isotope pattern deconvolution (IPD), based on multiple linear regression, serves as
simplified alternative data processing strategy to double spike isotope dilution calculations.
The outstanding advantage of this mathematical tool lies in the possibility of deconvolving
the isotope pattern in a spiked sample without knowing the quantities of enriched isotope
tracer being incorporated into the natural sample matrix as well as the degree of impurities
and species-interconversion (e.g. from sample preparation).
Here, the potential of IPD for environmental tracer studies is critically discussed, where
special emphasis is set on evaluating different data processing strategies on the example of
enriched stable Sr isotopes.1 The analytical key parameters such as blank (Kr, Sr and Rb),
variation of the natural Sr isotopic composition in the sample, mass bias, interferences (Rb)
and total combined uncertainty are considered.
A full metrological protocol for data processing using IPD is presented based on data
gained during two transgenerational marking studies of fish, where the transfer of a Sr isotope
double spike (84Sr and 86Sr) from female spawners of common carp (Cyprinus carpio L.) and
brown trout (Salmo trutta f.f.)2 to the centre of the otoliths of their offspring was studied by
(LA)-MC-ICP-MS.
1J. Irrgeher, A. Zitek, M. Cervicek and T. Prohaska, J. Anal. At. Spectrom., 2014, 29,
193-200.
2A. Zitek, J. Irrgeher, M. Kletzl, T. Weismann and T. Prohaska, Fish. Manage. Ecol.,
2013, 20, 654-361. |
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