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MS: Fachverband Massenspektrometrie

MS 9: Resonance Ionization Mass Spectrometry

MS 9.6: Vortrag

Donnerstag, 14. März 2019, 15:30–15:45, U A-Esch 2

In-situ extraction and TOF-SIMS-characterization of uranium-containing particles — •Paul Hanemann, Hauke Bosco, Martin Weiss, Manuel Raiwa, Laura Leifermann, and Clemens Walther — Institute of Radioecology and Radiation Protection, Leibniz University Hannover

Uranium bearing particles are omnipresent in the environment. However, they can be of natural or anthropogenic origin. Thus, identification poses a challenge. By combining SEM, EDX and micromanipulation, single particles are separated from the sample and deposited on um-diameter tungsten needles. The method does not require any sample preparation. Non-destructive mapping of elemental composition and isotopic ratios is performed by static time-of-flight secondary-ion mass-spectrometry (TOF-SIMS). This technique combines lateral resolution on the 100nm scale with ultratrace sensitivity and minimal invasiveness. A commercial IONTOF instrument has been modified and improved at the IRS [1, 2]. A broad spectrum of forensic data, including particle morphology and isotopic fingerprints of single particles was obtained. Extraction of uranium-containing particles was successfully performed on samples from the Chernobyl exclusion zone. The isotopic ratios of U-235, U-236 and U-238 were determined by TOF-SIMS measurements on the extracted particles. Comparing the obtained results to published data gives information on the origin and history of the particles. After the analysis, particles remain intact and are available for further experiments. [1] Franzmann et al., DOI: 10.1039/C7JA00423K [2] Franzmann et al., DOI: 10.1016/j.ijms.2017.10.003