Status of the AMS graphitization system in the dendrochronological laboratory at AGH-UST, Kraków

A new system for the preparation of graphite samples for radiocarbon (¹⁴C) measurement using an accelerator mass spectrometer (AMS) has been built in the Dendrochronological Laboratory at AGH-UST, Kraków. This system consists of three independent components. The first is the equipment for mechanical and chemical sample pre-treatment. The second is the vacuum line for sample sealing and the purification of CO₂. The third and central part of this system is a graphitization line, where graphite is produced from CO₂. In the first stage, chemical sample preparation was carried out to remove impurities. IAEA and NIST OxII standard materials were converted to CO₂ without pre-treatment. In the next step, samples were combusted to CO₂. The resulting CO₂ was released under vacuum and cryogenically purified for subsequent graphitization. The performance of the system was tested with NIST OxII, IAEA standards (IAEA C5, C6 and C7) and background samples. The test confirms good reproducibility of results obtained for the samples prepared using this system. The results of the 49 samples of NIST Ox-II, IAEA standards and blank samples were presented in this article.