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Studies on the Preparation of Small 14C Samples with an RGA and 13C-Enriched Material

Published online by Cambridge University Press:  18 July 2016

Jakob Liebl ,
Roswitha Avalos Ortiz ,
Robin Golser ,
Florian Handle ,
Walter Kutschera ,
Peter Steier  and
Eva Maria Wild
Jakob Liebl
Affiliation:
Vienna Environmental Research Accelerator (VERA), Faculty of Physics, Isotope Research, University of Vienna, Währinger Straße 17, A-1090 Vienna, Austria
Roswitha Avalos Ortiz
Affiliation:
Vienna Environmental Research Accelerator (VERA), Faculty of Physics, Isotope Research, University of Vienna, Währinger Straße 17, A-1090 Vienna, Austria
Robin Golser
Affiliation:
Vienna Environmental Research Accelerator (VERA), Faculty of Physics, Isotope Research, University of Vienna, Währinger Straße 17, A-1090 Vienna, Austria
Florian Handle
Affiliation:
Vienna Environmental Research Accelerator (VERA), Faculty of Physics, Isotope Research, University of Vienna, Währinger Straße 17, A-1090 Vienna, Austria
Walter Kutschera
Affiliation:
Vienna Environmental Research Accelerator (VERA), Faculty of Physics, Isotope Research, University of Vienna, Währinger Straße 17, A-1090 Vienna, Austria
Peter Steier*
Affiliation:
Vienna Environmental Research Accelerator (VERA), Faculty of Physics, Isotope Research, University of Vienna, Währinger Straße 17, A-1090 Vienna, Austria
Eva Maria Wild
Affiliation:
Vienna Environmental Research Accelerator (VERA), Faculty of Physics, Isotope Research, University of Vienna, Währinger Straße 17, A-1090 Vienna, Austria
*
Corresponding author. Email: [email protected].
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Abstract

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The minimum size of radiocarbon samples for which reliable results can be obtained in an accelerator mass spectrometry (AMS) measurement is in many cases limited by carbon contamination introduced during sample preparation (i.e. all physical and chemical steps to which samples were subjected, starting from sampling). Efforts to reduce the sample size limit down to a few μg carbon require comprehensive systematic investigations to assess the amount of contamination and the process yields. We are introducing additional methods to speed up this process and to obtain more reliable results. A residual gas analyzer (RGA) is used to study combustion and graphitization reactions. We could optimize the reaction process at small CO2 pressures and identify detrimental side reactions. Knowing the composition of the residual gas in a graphitization process allows a reliable judgment on the completeness of the reaction. Further, we use isotopically enriched 13C (≥98% 13C) as a test material to determine contamination levels. This offers significant advantages: 1) The measurement of 12C/13C in CO2 is possible on-line with the RGA, which significantly reduces turnaround times compared to AMS measurements; 2) Both the reaction yield and the amount of contamination can be determined from a single test sample.

The first applications of isotopically enriched 13C and the RGA have revealed that our prototype setup has room for improvements via better hardware; however, significant improvements of our sample processing procedures were achieved, eventually arriving at an overall contamination level of 0.12 to 0.15 μg C during sample preparation (i.e. freeze-drying, combustion, and graphitization) of μg-sized samples in aqueous solution, with above 50% yield.

Type
Sample Preparation
Information
Radiocarbon , Volume 52 , Issue 3: 20th Int. Radiocarbon Conference Proceedings , 2010 , pp. 1394 - 1404
Copyright
Copyright © 2010 by the Arizona Board of Regents on behalf of the University of Arizona 

References

Brown, TA, Southon, JR. 1997. Corrections for contamination background in AMS 14C measurements. Nuclear Instruments and Methods in Physics Research B 123(1–4):208–13.CrossRefGoogle Scholar
Drosg, R, Kutschera, W, Scholz, K, Steier, P, Wagenbach, D, Wild, EM. 2007. Treatment of small samples of particulate organic carbon (POC) for radiocarbon dating of ice. Nuclear Instruments and Methods in Physics Research B 259(1):340–4.CrossRefGoogle Scholar
Gagnon, AR, Jones, GA. 1993. AMS-graphite target production methods at the Woods Hole Oceanographic Institution during 1986–1991. Radiocarbon 35(2):301–10.CrossRefGoogle Scholar
Gagnon, AR, McNichol, AP, Donoghue, JC, Stuart, DR, von Reden, K. 2000. The NOSAMS sample preparation laboratory in the next millennium: progress after the WOCE program. Nuclear Instruments and Methods in Physics Research B 172(1–4):409–15.CrossRefGoogle Scholar
Hua, Q, Zoppi, U, Williams, AA, Smith, AM. 2004. Small-mass AMS radiocarbon analysis at ANTARES. Nuclear Instruments and Methods in Physics Research B 223–224:284–92.Google Scholar
Jenk, TM, Szidat, S, Schwikowski, M, Gäggeler, HW, Wacker, L, Synal, H-A, Saurer, M. 2007. Microgram level radiocarbon (14C) determination on carbonaceous particles in ice. Nuclear Instruments and Methods in Physics Research B 259(1):518–25.CrossRefGoogle Scholar
McNichol, AP, Gagnon, AR, Jones, GA, Osborne, EA. 1992. Illumination of a black box: analysis of gas composition during graphite target preparation. Radiocarbon 34(3):321–9.CrossRefGoogle Scholar
Němec, M, Wacker, L, Gäggeler, H. 2010. Optimization of the graphitization process at AGE-1. Radiocarbon 52(2–3):1380–93.CrossRefGoogle Scholar
Ruff, M, Wacker, L, Gäggeler, H, Suter, M, Synal, H-A, Szidat, S. 2007. A gas ion source for radiocarbon measurements at 200 kV. Radiocarbon 49(2):307–14.CrossRefGoogle Scholar
Santos, GM, Southon, JR, Griffin, S, Beaupre, SR, Druffel, ERM. 2007. Ultra small-mass AMS 14C sample preparation and analyses at KCCAMS/UCI facility. Nuclear Instruments and Methods in Physics Research B 259(1):293–302.CrossRefGoogle Scholar
Southon, J. 2007. Graphite reactor memory—Where is it from and how to minimize it? Nuclear Instruments and Methods in Physics Research B 259(1):288–92.CrossRefGoogle Scholar
Steier, P, Drosg, R, Fedi, M, Kutschera, W, Schock, M, Wagenbach, D, Wild, EM. 2006. Radiocarbon determination of particulate organic carbon in nontemperated, alpine glacier ice. Radiocarbon 48(1):69–82.CrossRefGoogle Scholar
Turner, P, Taylor, S, Clarke, E, Harwood, C, Cooke, K, Frampton, H. 2004. Calibration effects during natural gas analysis using a quadrupole mass spectrometer. Trends in Analytical Chemistry 23(4):281–7.CrossRefGoogle Scholar
Vandeputte, K, Moens, L, Dams, R, van der Plicht, J. 1998. Study of the 14C-contamination potential of C-impurities in CuO and Fe. Radiocarbon 40(1):103–10.Google Scholar
Vogel, JS, Southon, JR, Nelson, DE, Brown, TA. 1984. Performance of catalytically condensed carbon for use in accelerator mass spectrometry. Nuclear Instruments and Methods in Physics Research B 5(2):289–93.CrossRefGoogle Scholar