Radiocarbon Dating at Groningen: New and Updated Chemical Pretreatment Procedures

Abstract

The Centre for Isotope Research (CIO) at the University of Groningen has operated a radiocarbon (14C) dating laboratory for almost 70 years. In 2017, the CIO received a major upgrade, which involved the relocation of the laboratory to new purpose-built premises, and the installation of a MICADAS accelerator mass spectrometer. This period of transition provides an opportunity to update the laboratory’s routine procedures. This article addresses all of the processes and quality checks the CIO has in place for registering, tracking and pretreating samples for radiocarbon dating. Complementary updates relating to radioisotope measurement and uncertainty propagation will be provided in other forthcoming publications. Here, the intention is to relay all the practical information regarding the chemical preparation of samples, and to provide a concise explanation as to why each step is deemed necessary.

Radiocarbon-based approach capable of subannual precision resolves the origins of the site of Por-Bajin

“…α-cellulose is extracted from individual tree-ring samples and dated by AMS at the Centre for Isotope Research (CIO), Groningen, following standard procedures (26). The measured 14 C concentrations of the tree-ring sample are matched to tailored single-year-resolution reference curves through the classic statistical method of χ 2 (15,27) in order to estimate the felling date of the tree.…”

IntCal20 Tree Rings: An Archaeological Swot Analysis

“…Radiocarbon dating of the Lancaster Castle samples was undertaken by the Centre for Isotope Research, University of Groningen (GrM-), the Netherlands in 2018-2019, and at the Laboratory of Ion Beam Physics, ETH Zürich (ETH-), Switzerland in 2019. In Groningen, each ring was converted to α-cellulose using an intensified aqueous pretreatment (Dee et al 2020) and combusted in an elemental analyzer (IsotopeCube NCS), coupled to an isotope ratio mass spectrometer (Isoprime 100). The resultant CO 2 was graphitized by hydrogen reduction in the presence of an iron catalyst (Wijma et al 1996;Aerts-Bijma et al 1997).…”

Bayesian Modeling of Wood-Age Offsets in Cremated Bone

“…50% with 1% hydrochloric acid (Hüls et al 2010). Groningen treated CB samples with 1.5% sodium hypochlorite (48 hr, 20°C), followed by 6% (1M) acetic acid (24 hr, 20°C) (Dee et al 2019). Kiel hydrolyzed two aliquots of the extracted apatite for five CB samples to increase measurement precision.…”

“…Measurements in Brussels were performed on a Micadas (195.5 kV) AMS system (Boudin et al 2015). Kiel used a HVEE 3 MV Tandetron 4130 AMS system (Nadeau et al 1997) and Groningen used a Micadas (180 kV) AMS system (Dee et al 2019). The laboratories corrected the resulting 14 C-contents for fractionation using the simultaneously AMSmeasured 14 C/ 12 C and 13 C/ 12 C isotope ratios (Stuiver and Polach 1977).…”