Hamburg 2009 – wissenschaftliches Programm
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MS: Fachverband Massenspektrometrie
MS 4: AMS-Applications
MS 4.9: Vortrag
Dienstag, 3. März 2009, 12:45–13:00, VMP 8 R05
AGE: Optimization of the Graphitization Procedure — •Mojmír Němec1 and Lukas Wacker2 — 1Department of Chemistry and Biochemistry, University of Bern, Switzerland — 2Ion Beam Physics, ETH Zurich, Switzerland
The Automated Graphitization Equipment (AGE) was developed at ETH Zurich for fast and efficient sample preparations for radiocarbon measurement by accelerator mass spectrometry. Samples are combusted in an elemental analyzer and the resulting CO2 is absorbed on a single column filled with zeolite absorber. The CO2 is then released by heating the zeolite trap and transferred by gas expansion to the reactor, where it is reduced by H2 to graphite on the iron catalyst.
AGE was optimized to find conditions for the fastest graphitization reaction completion and the smallest isotopic fractionation with minimum formation of molecular fragments. The tuning was focused on the preconditioning of iron catalyst, reaction temperature (540-620∘C), H2/CO2 ratio (1.8-2.5) and also the suitable timing for each step of the whole procedure.
The results of the optimization experiments and the final graphitization procedure will be presented.