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MS: Fachverband Massenspektrometrie
MS 7: Accelerator Mass Spectrometry III
MS 7.7: Vortrag
Donnerstag, 14. März 2024, 12:45–13:00, HS 3042
Utilizing δ13C from IRMS to improve the precision of AMS measurments — •Martina Gwozdz1, Andrea Jaeschke2, Stefan Heinze1, Janet Rethemeyer2, Dennis Mücher1, and Markus Schiffer1 — 1University of Cologne, Institute for Nuclear Physics, Cologne, Germany — 2University of Cologne, Institute for Geology and Mineralogy, Cologne, Germany
Within the CRC1211 project-Evolution at the Dry Limit, there is a need for precise dating analysis on soil samples from the Atacama Desert, which are characterized by low carbon contents. We employ an elemental analyser, an isotope ratio mass spectrometer and an existing gas interface in conjunction with the 6 MV AMS system of CologneAMS. This setup facilitates a fully automated, online analysis of 14C/12C, while also delivering accurate δ13C values. To address the compatibility of δ13C values derived from AMS and IRMS measurements for fractionation correction, we simultneously determined δ13C values from various standard materials using both AMS and IRMS. Our findings reveal that the mean δ13C values from AMS and IRMS align within their respective error ranges. Consequently, we advocate for the utilization of the more precise δ13C values from IRMS for an effective and refined AMS fractionation correction. Notably, our investigation did not unveil any correlation between the observed scattering of δ13C AMS values and fluctuations in the 14C/12C AMS ratios. This insight sheds light on the origin of small fluctuations beyond statistical expectations in radiocarbon AMS dating applications.