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Gewählte Publikation:

Kappel, S; Boulyga, SF; Dorta, L; Günther, D; Hattendorf, B; Koffler, D; Laaha, G; Leisch, F; Prohaska, T.
(2013): Evaluation strategies for isotope ratio measurements of single particles by LA-MC-ICPMS.
Anal Bioanal Chem. 2013; 405(9):2943-2955 FullText FullText_BOKU

Data evaluation is a crucial step when it comes to the determination of accurate and precise isotope ratios computed from transient signals measured by multi-collector-inductively coupled plasma mass spectrometry (MC-ICPMS) coupled to, for example, laser ablation (LA). In the present study, the applicability of different data evaluation strategies (i.e. xxxpoint-by-pointxxx, xxxintegrationxxx and xxxlinear regression slopexxx method) for the computation of U-235/U-238 isotope ratios measured in single particles by LA-MC-ICPMS was investigated. The analyzed uranium oxide particles (i.e. 9073-01-B, CRM U010 and NUSIMEP-7 test samples), having sizes down to the sub-micrometre range, are certified with respect to their U-235/U-238 isotopic signature, which enabled evaluation of the applied strategies with respect to precision and accuracy. The different strategies were also compared with respect to their expanded uncertainties. Even though the xxxpoint-by-pointxxx method proved to be superior, the other methods are advantageous, as they take weighted signal intensities into account. For the first time, the use of a xxxfinite mixture modelxxx is presented for the determination of an unknown number of different U isotopic compositions of single particles present on the same planchet. The model uses an algorithm that determines the number of isotopic signatures by attributing individual data points to computed clusters. The U-235/U-238 isotope ratios are then determined by means of the slopes of linear regressions estimated for each cluster. The model was successfully applied for the accurate determination of different U-235/U-238 isotope ratios of particles deposited on the NUSIMEP-7 test samples.
Autor*innen der BOKU Wien:
Kappel Stefanie
Koffler Daniel
Laaha Gregor
Leisch Friedrich
Prohaska Thomas

Find related publications in this database (Keywords)
U isotope ratios
Laser ablation MC-ICPMS
Single particles
Short transient signals
Data evaluation strategies
Finite mixture model

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