A New Graphitization System for Radiocarbon Dating with AMS in the Dendrochronological Laboratory at AGH-UST Kraków

Abstract

A new vacuum system for the preparation of graphite samples for radiocarbon (14C) measurement using an accelerator mass spectrometer (AMS) was constructed at the Dendrochronological Laboratory in AGH-UST Kraków. The central part of the system is a manual vacuum line for the production of graphite from carbon dioxide for subsequent AMS measurements. The graphitization system can handle up to five samples simultaneously, and the process lasts for approximately 1 hour. The graphitization line was built to support the preparation of wood samples for a project dedicated to dating a subfossil tree from the Younger Dryas period. For this purpose, the chemical preparation procedure for wood samples was optimized to obtain more reliable results. This includes the extraction of α-cellulose to increase the precision of the age determination. The performance of the system was tested with NIST OxII, IAEA standards (IAEA C3, C5, C6, and C8), and background samples. The results of the 13 samples of subfossil wood were tested and are presented. The methodology gives good reproducibility of results obtained for the samples prepared using this system.

The spatial and temporal reconstruction of a medieval moat ecosystem

“…14 C measurements were carried out with a 3-photomultiplier spectrometer, the HIDEX 300SL and Quantulus 1220. Organic samples dated using the AMS technique were combusted, purified, and graphitised with Fe catalyst 70 . The mixture of graphite and Fe powder was pressed into a target holder and measured with the AMS system at the Centre for Applied Isotope Studies at the University of Georgia, USA or in the Accelerator Mass Spectrometry Laboratory (D-AMS laboratory code) in Seattle, USA (see 71 for details).…”

THE CULT AREA (ZOLNIK) FROM A SCYTHIAN HILLFORT IN CHOTYNIEC NEAR RADYMNO (SOUTHEASTERN POLAND) IN THE CONTEXT OF RADIOCARBON DATING

“…Dating of 2 small samples (ca. 1 g charcoal) using the AMS technique was made in the Laboratory of Absolute Dating, Poland (graphite preparation; Kra˛piec et al 2018) and CAIS, University of Georgia (measurements; Cherkinsky et al 2010).…”

ABSOLUTE DENDROCHRONOLOGICAL SCALE FOR PINE (PINUS SYLVESTRIS L.) FROM UJŚCIE (NW POLAND), DATED USING RAPID ATMOSPHERIC 14C CHANGES

“…After the pretreatment, around 4 mg of α-cellulose, extracted from each sample, was combusted to CO 2 and subsequently reduced to graphite (Krąpiec et al 2018). The resulting mixture of graphite and Fe powder was pressed into a target holder for AMS 14 C measurements.…”