Evaluation of EC comparison on the determination of 40K, 90Sr and 137Cs in bilberry powder

The evaluation is presented of a laboratory comparison (LC) on 90Sr, 40K and 137Cs in dried bilberries organised in 2011 by the IRMM. The activity concentrations reported by 88 participant laboratories are compared to the reference values of the new reference material IRMM-426 Wild Berries. 9 % and 17 % of activity concentration results for 137Cs and 40K, respectively, deviate more than 20 % from the reference values, a result worse than that obtained in previous LCs. For 90Sr, about 88 % of results lie within 30 % of the reference value, better than observed in previous LCs. But only 56 % of 90Sr results are satisfactory in terms of the En criterion, indicating difficulties with a complete uncertainty estimation.