14C Interlaboratory Comparison in the UK: Experiment Design, Preparation and Preliminary Results

Abstract

An interlaboratory comparison experiment for 14C measurements has been organized jointly by the Harwell and British Museum laboratories to include the working radiocarbon laboratories of the United Kingdom. The experiment has been run along the lines of that organized by the IAEA for tritium and has explored the problems of sample preparation, verification of equivalent levels, and presentation of results. Samples of benzene representing 5 age equivalent levels between twice modern and 20,000 years old have been prepared and distributed for measurement either by direct counting (liquid scintillation) or full process tests. Preliminary results received show excellent agreement both between laboratories and in comparison with the known relative activities of the prepared solutions. The possibility of extending the experiment to cover different sample types and a wider distribution of testing laboratories is briefly discussed.