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Sources of Radon Contamination in 14C Dating

Published online by Cambridge University Press:  18 July 2016

Nada Horvatinčić ,
Bogomil Obelić ,
Ines Krajcar Bronić ,
Dušan Srdoč  and
Romana Bistrović
Nada Horvatinčić
Affiliation:
Rudjer Bošković Institute, P.O. Box 1016, 10001 Zagreb, Croatia
Bogomil Obelić
Affiliation:
Rudjer Bošković Institute, P.O. Box 1016, 10001 Zagreb, Croatia
Ines Krajcar Bronić
Affiliation:
Rudjer Bošković Institute, P.O. Box 1016, 10001 Zagreb, Croatia
Dušan Srdoč
Affiliation:
Rudjer Bošković Institute, P.O. Box 1016, 10001 Zagreb, Croatia
Romana Bistrović
Affiliation:
Rudjer Bošković Institute, P.O. Box 1016, 10001 Zagreb, Croatia
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Abstract

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We investigated the effect of radon (222Rn) contamination of samples and chemicals used for sample preparation and gas purification on the 14C age of samples. Radon count rate was monitored over several 222Rn half-lives in a proportional counter filled with methane. We analyzed ca. 240 samples of fossil and recent wood, charcoal, bone, dissolved inorganic carbon in water, travertine, peat, aquatic plants, organic soil and atmospheric CO2 for 222Rn contamination. Chemicals used for gas purification (MnO2, Mg(ClO4)2), ruthenium-coated pellets used for catalytic reduction of CO2 to CH4, and acids used for dissolution of calcareous samples (HCl and H3PO4) are also potential sources of Rn. Most geological samples contained a significant amount of Rn, as opposed to samples of wood, charcoal, aquatic plants and atmospheric CO2. We also studied Rn contamination of water samples during tritium activity measurements in a CH4-filled gas proportional counter. We found an increased count rate in the 3H channel, as well as above the 20 keV region in Rn-contaminated groundwater samples.

Type
V. Advances in Measurement Techniques
Information
Radiocarbon , Volume 37 , Issue 2 , 1995 , pp. 749 - 757
Copyright
Copyright © the Department of Geosciences, The University of Arizona 

References

Bruns, M. (ms.) 1979 Gas Chromatographic mit 222Rn. Ph.D. dissertation, Institut für Umweltphysik, Heidelberg.Google Scholar
de Vries, H. L. 1957 The removal of radon from CO2 for use in 14C age measurements. Applied Scientific Research B 6: 461–470.Google Scholar
Hood, D., Hatfield, R., Patrick, C., Stipp, J., Tamers, M., Leidl, R., Lyons, B., Polach, H., Robertson, S. and Zhou, W. 1989 Radon elimination during benzene preparation for radiocarbon dating by liquid scintillation spectrometry. In Long, A., Kra, R. S. and Srdoč, D., eds., Proceedings of the 13th International 14C Conference. Radiocarbon 31(3): 254–259.Google Scholar
Horvatinčić, N. 1980 Radiocarbon and tritium measurements in water samples and application of isotopic analyses in hydrology. Fizika 12(S2): 201–218.Google Scholar
Krajcar Bronić, I., Obelić, B. and Srdoč, D. 1986 The simultaneous measurement of tritium activity and the background count rate in a proportional counter by the Povinec method: Three years experience at the Ruder Bošković Institute. Nuclear Instruments and Methods in Physics Research B 17: 498–500.Google Scholar
Nydal, R. 1983 Radon problem in 14C dating. In Stuiver, M. and Kra, R. S., eds., Proceedings of the 11th International 14C Conference. Radiocarbon 25(2): 501–510.Google Scholar
Obelić, B., Krajcar Bronić, I., Srdoč, D. and Horvatinčić, N. 1986 Environmental 14C levels around the 632 MWe Nuclear Power Plant Krško in Yugoslavia. In Stuiver, M. and Kra, R. S., eds., Proceedings of the 12th International 14C Conference. Radiocarbon 28(2A): 644–648.CrossRefGoogle Scholar
Polach, H. and Kaihola, L. 1988 Determination of radon by liquid scintillation α/β particle spectrometry: Towards the resolution of a 14C dating problem. Radiocarbon 30(1): 19–24.CrossRefGoogle Scholar
Schoch, H. and Münnich, K. O. 1981 Routine performance of a new multi-counter system for high-precision 14C dating. In Proceedings of the Symposium Methods of Low-Level Counting and Spectrometry. Vienna, IAEA: 361–370.Google Scholar
Siegenthaler, U., Oeschger, H., Schotterer, U. and Hänni, K. 1975 Conversion of water to a counting gas for low-level tritium measurements by means of aluminium carbide. International Journal of Applied Radiation and Isotopes 26: 459–464.Google Scholar
Srdoč, D. and Sliepčević, A., 1963 Carbon dioxide proportional counter; effects of gaseous impurities and gas purification. Journal of Applied Radiation and Isotopes 14: 481–488.Google Scholar
Srdoč, D., Breyer, B and Sliepčević, A., 1971 Rudjer Bošković Institute radiocarbon measurements I. Radiocarbon 13(1): 135–140.CrossRefGoogle Scholar