Merchel S., Bremser W., Bourles D. L., Czeslik U., Erzinger J., Kummer N. A., Leanni Laetitia, Merkel B., Recknagel S., Schaefer U. (2013). Accuracy of Be-9-data and its influence on Be-10 cosmogenic nuclide data. Journal of Radioanalytical and Nuclear Chemistry, 298 (3), p. 1871-1878. ISSN 0236-5731.
Titre du document
Accuracy of Be-9-data and its influence on Be-10 cosmogenic nuclide data
Merchel S., Bremser W., Bourles D. L., Czeslik U., Erzinger J., Kummer N. A., Leanni Laetitia, Merkel B., Recknagel S., Schaefer U.
Source
Journal of Radioanalytical and Nuclear Chemistry, 2013,
298 (3), p. 1871-1878 ISSN 0236-5731
A Be-9-solution has been chemically prepared from phenakite (Be2SiO4) mineral grains as commercial Be-9-solutions are too high in long-lived Be-10. The solution is intended to be used as a carrier for radiochemical separation of Be-10 to be measured by accelerator mass spectrometry (AMS). Thus, accurate data of the Be-9-concentration of this solution is essential to guarantee for high-accuracy Be-10 data in the future. After devastating preliminary results (similar to 8 % standard deviation), eight laboratories finally produced twelve individual results by four different analytical methods. A certain lab and method bias might be identified by sophisticated statistical evaluation. Some laboratories also (grossly) underestimate their uncertainties. Thus, the simple weighted mean of this round-robin exercise needed to be corrected by introducing additional allowances (Paule-Mandel-approach). The final result has been calculated to (2,246 +/- A 11) mu g Be-9/(g solution) with a reasonably low weighted standard deviation of 0.49 %. The maximum deviation of a single lab value from the weighted mean is 2.4 % when removing one Grubbs outlier (11 % off from the mean) from the data set. As Be-10-data, which is usually calculated from measured Be-10/Be-9 by AMS and stable Be-9, cannot be more accurate than the determined Be-9-concentration, it seems highly advisable to establish or improve quality assurance by having self-made carrier-solutions analysed at more than a single lab and regularly taking part in round-robin exercises.
Plan de classement
Sciences fondamentales / Techniques d'analyse et de recherche [020]
;
Sciences de la Terre : généralités [060]