Accounting for Overcounting Induced by 222Rn Contamination in 14C Measurements Performed with Liquid Scintillation Counting

Maksymilian Jędrzejowski; Danuta J. Michczyńska; Adam Michczyński; Marzena Kłusek; Konrad Tudyka

doi:10.2478/geochr-2023-0007

Abstract

This research paper introduces a methodology for estimating overcounting resulting from uranium series radionuclides, with a specific focus on ²²²Rn contamination. The method is demonstrated using the Quantulus 1220^TM spectrometer. Exponential fitting is employed for the calculations, utilizing a custom algorithm developed in MATLAB^® R2022b. The proposed method allows for the determination of the sample count rate correction, F¹⁴C and radiocarbon age without the need for additional chemical treatment or specialized electronics during liquid scintillation counting (LSC) measurements with the Quantulus 1220^TM spectrometer. However, the method does have certain limitations. It requires a significant number of cycles and extended measurement time per cycle, but it can be applied to samples with significant ²²²Rn contamination that require rapid ¹⁴C analysis.

References

Box GEP and Cox DR, 1964. An analysis of transformations. Journal of the Royal Statistical Society Series B (Methodological) 26(2): 211–243. DOI: 10.1111/j.2517-6161.1964.tb00553.x.
Open DOI Search in Google Scholar Back to article
Cothern CR and Rebers PA, editors, 1990. Radon, Radium and Uranium in Drinking Water. Lewis Publishers, Chelsea (United States): 286p.
Search in Google Scholar Back to article
de Vries HL, 1957. The removal of radon from CO2 for use in 14C age measurements. Applied Scientific Research, Section B 6(1): 461–470. DOI: 10.1007/bf02920403.
Open DOI Search in Google Scholar Back to article
Gupta SK and Polach HA, 1985. Radiocarbon Dating Practices at ANU: Australian National University. Radiocarbon Laboratory, Research School of Pacific Studies, Canberra (Australia): 176p.
Search in Google Scholar Back to article
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. Radiocarbon 31(3): 254–259. DOI: 10.1017/s0033822200011760.
Open DOI Search in Google Scholar Back to article
Horvatinčić N, Obelić B, Krajcar Bronić I, Srdoč D and Bistrović R, 1995. Sources of radon contamination in 14C dating. Radiocarbon 37(2): 749–757. DOI: 10.1017/s0033822200031295.
Open DOI Search in Google Scholar Back to article
IAEA Nuclear Data Services (NDS). NDS ENSDF Database. International Atomic Energy Agency, Vienna, Austria. WEB site: https://www-nds.iaea.org/relnsd/NdsEnsdf/QueryForm.html. Accessed 2023 June 3.
Search in Google Scholar Back to article
Kim C-K, Martin P and Fajgelj A, 2008. Quantification of measurement uncertainty in the sequential determination of 210Pb and 210Po by liquid scintillation counting and alpha-particle spectrometry. Accreditation and Quality Assurance 13(12): 691–702. DOI: 10.1007/s00769-008-0437-z.
Open DOI Search in Google Scholar Back to article
McCormac FG, 1992. Liquid scintillation counter characterization, optimization and benzene purity correction. Radiocarbon 34(1): 37–45. DOI: 10.1017/s0033822200013400.
Open DOI Search in Google Scholar Back to article
Michczyńska DJ, Krąpiec M, Michczyński A, Pawlyta J, Goslar T, Nawrocka N, Piotrowska N, Szychowska-Krąpiec E, Waliszewska B and Zborowska M, 2018. Different pretreatment methods for 14C dating of Younger Dryas and Allerød pine wood (Pinus sylvestris L.). Quaternary Geochronology 48: 38–44. DOI: 10.1016/j.quageo.2018.07.013.
Open DOI Search in Google Scholar Back to article
National Nuclear Data Center (NNDC). NuDat 3.0: Nuclear Structure and Decay Data. 3.0. National Nuclear Data Center, Brookhaven National Laboratory, Brookhaven, NY. WEB site: https://www.nndc.bnl.gov/nudat3/. Accessed 2023 June 3.
Search in Google Scholar Back to article
Nero AV and Nazaroff WW, 1984. Characterising the source of radon indoors. Radiation Protection Dosimetry 7(1–4): 23–39. DOI: 10.1093/oxfordjournals.rpd.a082958.
Open DOI Search in Google Scholar Back to article
Nydal R, 1983. The radon problem in 14C dating. Radiocarbon 25(2): 501–510. DOI: 10.1017/s0033822200005798.
Open DOI Search in Google Scholar Back to article
Pawlyta J, Pazdur A, Rakowski AZ, Miller BF and Harkness DD, 1997. Commissioning of a Quantulus 1220™ liquid scintillation beta spectrometer for measuring 14C and 3H at natural abundance levels. Radiocarbon 40(1): 201–209. DOI: 10.1017/S0033822200018051.
Open DOI Search in Google Scholar Back to article
Pazdur A, 1979. On the application of a proportional counter to continuous monitoring of 222Rn concentration in the study of thermal diffusion in Rn–CO2 mixture. Nuclear Instruments and Methods 161(1): 123–129. DOI: 10.1016/0029-554x(79)90369-0.
Open DOI Search in Google Scholar Back to article
Pazdur A, Fogtman M, Michczyński A and Pawlyta J, 2003. Precision of 14C dating in gliwice radiocarbon laboratory. FIRI programme. Geochronometria 22(1): 27–40.
Search in Google Scholar Back to article
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. DOI: 10.1017/S0033822200043927.
Open DOI Search in Google Scholar Back to article
Salonen L and Hukkanen H, 1997. Advantages of low-background liquid scintillation alpha-spectrometry and pulse shape analysis in measuring 222Rn, uranium and 226Ra in groundwater samples. Journal of Radioanalytical and Nuclear Chemistry 226(1–2): 67–74. DOI: 10.1007/bf02063626.
Open DOI Search in Google Scholar Back to article
Schönhofer F, 1989. Determination of radon-222 and radium-226 in mineral water and drinking water – a survey in Austria. The Analyst 114(10): 1345–1347. DOI: 10.1039/an9891401345.
Open DOI Search in Google Scholar Back to article
Theodórsson P, 2005a. A simple, extremely stable single-tube liquid scintillation system for radiocarbon dating. Radiocarbon 47(1): 89–97. DOI: 10.1017/s003382220005222x.
Open DOI Search in Google Scholar Back to article
Theodórsson P, 2005b. Simultaneously measuring 14C and radon in benzene dating samples. Radiocarbon 47(2): 231–234. DOI: 10.1017/s0033822200019731.
Open DOI Search in Google Scholar Back to article
Tudyka K and Bluszcz A, 2011. Very low cost multichannel analyzer with some additional features. Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment 659(1): 419–421. DOI: 10.1016/j.nima.2011.09.015.
Open DOI Search in Google Scholar Back to article
Tudyka K and Pazdur A, 2010. Radiocarbon dating of peat profile with metallurgy industry evidence. Geochronometria 35: 3–9. DOI 10.2478/v10003-010-0007-3.
Open DOI Search in Google Scholar Back to article
Tudyka K, Bluszcz A, Kozłowska B, Pawlyta J and Michczyński A, 2015. Low level 14C measurements in freshly prepared benzene samples with simultaneous 214Bi/214Po pairs counting for routine 222Rn contamination correction. Radiation Measurements 74: 6–11. DOI: 10.1016/j.radmeas.2015.01.010.
Open DOI Search in Google Scholar Back to article
Tudyka K, Miłosz S, Ustrzycka A, Barwinek S, Barwinek W, Walencik-Łata A, Adamiec G and Bluszcz A, 2017. A low level liquid scintillation spectrometer with five counting modules for 14C, 222Rn and delayed coincidence measurements. Radiation Measurements 105: 1–6. DOI: 10.1016/j.radmeas.2017.06.003.
Open DOI Search in Google Scholar Back to article
Tudyka K, Pawełczyk F and Michczyński A, 2021. Bias arising from 222Rn contamination in standardized methods for bio-based content determination and a simple removal method. Measurement 167: 108263. DOI: 10.1016/j.measurement.2020.108263.
Open DOI Search in Google Scholar Back to article

Accounting for Overcounting Induced by 222Rn Contamination in 14C Measurements Performed with Liquid Scintillation Counting

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