Hostname: page-component-78c5997874-j824f Total loading time: 0 Render date: 2024-11-03T01:25:36.029Z Has data issue: false hasContentIssue false

Interlaboratory Comparisons of 14C Measurements in Milk and Vegetation

Published online by Cambridge University Press:  18 July 2016

G. M. Milton
Affiliation:
Environmental Research Branch, Chalk River Laboratories, Chalk River, Ontario, Canada K0J 1J0
S. J. Kramer
Affiliation:
Environmental Research Branch, Chalk River Laboratories, Chalk River, Ontario, Canada K0J 1J0
J. C. D. Milton
Affiliation:
Nuclear Physics Branch, Chalk River Laboratories, Chalk River, Ontario, Canada K0J 1J0
Rights & Permissions [Opens in a new window]

Abstract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

The need for increased quality assurance for radiocarbon measurements performed by the monitoring laboratories at nuclear stations has spurred the introduction of a number of interlaboratory comparisons. We organized two such intercomparisons: the first set, circulated in 1994, consisted of two milk samples, one containing current global levels of 14C, the other containing an added spike of 14C-methylated casein. The second set, circulated in 1995, consisted of two samples of natural vegetation growing on the site of the Chalk River Laboratories (CRL), containing two different levels of 14C, both well above global background. The response to our invitation to participate in these studies was very encouraging; six laboratories took part in the first intercomparison, eleven in the second. The list included both monitoring laboratories and those whose main function is 14C dating. Understandably, some of the latter preferred not to analyze the higher-activity samples. The results in 3 of the 4 data sets were consistent with a statistical distribution based on the reported errors. This report provides details of two intercomparisons, including the preparation of the samples, which may now be considered potential secondary reference materials, the range of analytical techniques in use at the participating laboratories, and a statistical analysis of the results returned to us.

Type
Part 1: Methods
Copyright
Copyright © The American Journal of Science 

References

Aitchison, T. C., Scott, E. M., Harkness, D. D., Baxter, M. S. and Cook, G. T. 1990 Report on Stage 3 of the International Collaborative Program. In Scott, E. M., Long, A. and Kra, R. S., eds., Proceedings of the International Workshop on Intercomparison of 14C Laboratories. Radiocarbon 32(3): 271278.CrossRefGoogle Scholar
Barington, P. R. 1969 Data Reduction and Error Analysis for the Physical Sciences. New York, McGraw-Hill: 336 p.Google Scholar
Clark, R. M. 1975 A calibration curve for radiocarbon dates. Antiquity 49: 251264.CrossRefGoogle Scholar
Cook, G. T., Harkness, D. D., Miller, B. F., Scott, E. M., Baxter, M. S. and Aitchison, T. C. 1990 International collaborative study: Structuring and sample preparation. In Scott, E. M., Long, A. and Kra, R. S., eds., Proceedings of the International Workshop on Intercomparison of 14C Laboratories. Radiocarbon 32(3): 267270.CrossRefGoogle Scholar
Cooper, E. L. and Rao, R. R. 1995 Pilot study of labelling bovine muscle tissue with 14C The Science of the Total Environment 173/174: 275282.CrossRefGoogle Scholar
Harkness, D. D., Cook, G. T., Miller, B. F., Scott, E. M. and Baxter, M. S. 1989 Design and preparation of samples for the International Collaborative Study. In Long, A., Kra, R. S. and Srdoč, D., eds., Proceedings of the 13th International 14C Conference. Radiocarbon 31(3): 414421.CrossRefGoogle Scholar
International Atomic Energy Agency 1991 Consultants’ Group Meeting on 14C Reference Materials for Radiocarbon Laboratories. February 18–20. Vienna, Austria.Google Scholar
International Study Group (ISG) 1982 An inter-laboratory comparison of radiocarbon measurements in tree rings. Nature 298: 619623.CrossRefGoogle Scholar
Milton, G. M. 1993 Report on Workshop on the Environmental Behaviour of Carbon 14, AECL Report, RC-1009.Google Scholar
Milton, G. M. and Brown, R. M. 1993 A Survey of Analytical Techniques for the Measurement of Carbon-14. AECL Report, AECL-10803, COG −93–335.Google Scholar
Neil, B. J. C. 1993 Inter-office memo, Ontario Hydro.Google Scholar
Otlet, R. L., Walker, A. J., Hewson, A. D. and Burleigh, R. 1980 14C interlaboratory comparison in the UK: Experiment design, preparation and preliminary results. In Stuiver, M. and Kra, R. S., eds., Proceedings of the 10th International 14C Conference. Radiocarbon 22(3): 936947.CrossRefGoogle Scholar
Polach, H. A. 1972 Cross checking of the NBS oxalic acid and secondary laboratory radiocarbon dating standards. In Rafter, T. A. and Grant-Taylor, T., eds. Proceedings of the 8th International Conference on Radiocarbon Dating: Wellington, Royal Society of New Zealand, Vol. 2: 688717.Google Scholar
Polach, H. A. 1979 Correlation of 14C activity of NBS oxalic acid with Arizona 1985 wood and ANU sucrose standards. In Berger, R. and Suess, H. E., eds, Proceedings of the 9th International 14C Conference. Berkeley, University of California Press: 115124.Google Scholar
Rao, R. R., Cooper, E. L. and Milton, G. M. 1995 Preparation and evaluation of the homogeneity of milk as a candidate reference material for carbon-14. Fresenius Journal of Analytical Chemistry 352: 136142.CrossRefGoogle Scholar
Rozanski, K., Stichler, W., Gonfiantini, R., Scott, E. M., Beukens, R. P., Kromer, B. and van der Plicht, J. 1992 The IAEA 14C intercomparison exercise 1990. In Long, A. and Kra, R. S., eds., Proceedings of the 14th International 14C Conference. Radiocarbon 34(3): 506519.CrossRefGoogle Scholar
Scott, E. M., Aitchison, T. C., Harkness, D. D., Baxter, M. S. and Cook, G. T. 1989 An interim progress report on stages 1 and 2 of the International Collaborative Program. In Long, A., Kra, R. S. and Srdoč, D., eds., Proceedings of the 13th International 14C Conference. Radiocarbon 31(3): 414421.CrossRefGoogle Scholar
Scott, E. M., Aitchison, T. C., Harkness, D. D., Cook, G. T. and Baxter, M. S. 1990 An overview of all three stages of the International Radiocarbon Intercomparison. In Scott, E. M., Long, A. and Kra, R. S., eds., Proceedings of the International Workshop on Intercomparison of 14C Laboratories. Radiocarbon 32(3): 309319.CrossRefGoogle Scholar