Berlin 2014 – wissenschaftliches Programm

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MS: Fachverband Massenspektrometrie

MS 6: Poster

MS 6.2: Poster

Mittwoch, 19. März 2014, 14:00–14:00, DO24 Foyer

AMS of actinides in groundwater: development of a new procedure for trace analysis of Np, Pu, Am and Cm isotopes — •Francesca Quinto¹, Markus Lagos¹, Markus Plaschke¹, Thorsten Schäfer¹, Peter Steier², and Horst Geckeis¹ — ¹Karlsruhe Institute of Technology, Institute for Nuclear Waste Disposal (KIT-INE), Hermann-von Helmholtz-Platz 1, D-76344 Eggenstein-Leopoldshafen, Germany — ²VERA Laboratory, Faculty of Physics, University of Vienna, Währinger Straße 17, A-1090 Vienna, Austria

In order to assess the actinides contamination in groudwater, their geochemistry is intensely studied in field and laboratory experiments focusing on speciation and ways of transport through the aquifers. A challenge lies in the analysis of actinides below ppq levels. We present a new analytical protocol suited to the measurement by accelerator mass spectrometry of Np, Pu, Am and Cm isotopes without previous chemical separation from each other. The actinides are quantitatively co-precipitated with Fe-hydroxide from the groundwater specimens. This procedure allows the pre-concentration of the actinides from the bulk elements and their incorporation into a sample matrix suited to the AMS measurements. The chemical yield of the co-precipitation is estimated measuring samples with suitable spikes by HR ICP-MS. At the AMS sytem: a) the ionization yield of Np, Pu, Am and Cm in the given sample matrix, b) the maximum number of nuclides per sample allowing detection limits below 0.01 ppq, and c) the influence of the laboratory background on the results, are determined.