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MS: Fachverband Massenspektrometrie

MS 7: Accelerator Mass Spectrometry and Applications I

MS 7.5: Vortrag

Mittwoch, 20. März 2013, 15:15–15:30, F 442

Some pitfalls in chemical sample preparation for accelerator mass spectrometry — •Silke Merchel — HZDR, Dresden, Germany

Sophisticated sample preparation including the determination of stable nuclides are an essential prerequisite for high-accuracy accelerator mass spectrometry (AMS) data. Improvements in the low-level regime already paid back [1], however, some pitfalls still exist or are (re-) appearing due to recent developments: 1.) As most samples prepared for ¹⁰Be-AMS need the addition of ⁹Be in the form of a liquid solution of known ⁹Be-concentration and commercial solutions contain too much ¹⁰Be, solutions from minerals originating from deep mines have been established. Special attention has recently been paid to the preparation of such a ⁹Be-carrier by the determination of the ⁹Be-value by an interlaboratory comparison. It could be shown that deviations between different labs exist, thus, it is strongly advised to have such solutions analysed at more than a single lab to prevent incorrect ¹⁰Be-results. 2.) In our approach to analyse as many radionuclides as possible in a single meteorite sample, small changes in the established chemical separation [2] have been tested. Though, the secondary formation of partially insoluble compounds of Mg and Al by the pressure digestion is strongly influenced, thus, yielding to too low ²⁷Al-results in the taken aliquot and overall incorrect ²⁶Al-results. Ackn.: DREAMS-team and colleagues performing ⁹Be- and ²⁷Al-measurements (BAM, GFZ, HZDR, CEREGE, TUBAF, U Cologne, VKTA). Ref.: [1] NIMB 266 (2008) 4921. [2] Radiochim. Acta 84 (1999) 215.