Evaluation of a proficiency test of 131I, 134Cs and 137Cs in maize powder

In 2017, JRC-Geel organised a proficiency test for 120 participants on the massic activity determination of ¹³¹I, ¹³⁴Cs and ¹³⁷Cs in maize powder. The proficiency test reference material was produced by spiking blank maize powder. The material was characterised for its radioactive content using γ-ray spectrometry. The z scores of the reported massic activity were acceptable in 92% of the results for ¹³¹I, and in 94% for both ¹³⁴Cs and ¹³⁷Cs. The ζ scores were consistent with the reference value for 66% of the results for ¹³¹I, 56% for ¹³⁴Cs and 68% for ¹³⁷Cs.

Evaluation of the 2014 EC measurement comparison on (137)Cs in air filters

In 2014, the Joint Research Centre organised an interlaboratory comparison of (137)Cs measurement in air filters. This paper describes the context of the European measurement comparisons, as well as the technical implementation. Furthermore, sample treatment and measurements performed by participating laboratories are discussed and finally the evaluation of comparison results is presented. The intercomparison results are such that 71 out of the 76 laboratories (i.e. 93.4%) reported values within ±33% range of the reference value.

Spiked environmental matrix for use as a reference material for gamma-ray spectrometry: Production and homogeneity test

The application of a spiking method for reference material production and its utilisation for a food matrix is presented. The raw rice powder was tested by means of γ-ray spectrometry and spiked with a (137)Cs solution. The spiked material was mixed and tested for homogeneity. The future use of the rice powder reference material after the entire characterisation cycle will be for γ-ray spectrometry method validation.