Ensuring safe feed is an important component in the efforts to reduce and prevent food safety hazards.
The activities of 131I, 134Cs and 137Cs must be monitored to assess the impact of nuclear industry on the environment and food chain. Elevated activity levels of these radionuclides are indications of a nuclear incident and potentially of an emergency. Measuring radioactivity correctly is not trivial. In order to obtain reliable monitoring results, DG SANTE asked JRC to establish a standardised method for the determination of 131I, 134Cs and 137Cs in animal feed.
The best measurement method for these radionuclides is high-resolution gamma-ray spectrometry. This method has been described in the new EN 17462 standard. Covered by DG SANTE Mandate M/523 under the auspice of CEN technical committee 327, the standard was developed, written, tested, and verified by the radionuclide metrology team of JRC Geel.
In collaboration with the reference materials production team of JRC Geel, the in-house validation of performance characteristics of the method was conducted including the trueness parameter. Later also, an interlaboratory trial was conducted to evaluate the precision of the method. These validations included the production of reference materials using three matrices (poultry feed, hay from Chernobyl, and maize) at two different levels of activity. Since one of the radionuclides (131I) is relatively short-lived with only 8 days half‑life, no certified reference material (CRM) containing this radionuclide exists. Therefore, it was necessary to produce all testing materials by spiking animal feed matrices and sending them to laboratories on very short notice.
A procedure of spiking was tested previously and described in a report entitled "Evaluation of spiking methods for the preparation of a Proficiency Testing material in cereal matrices" (Sobiech-Matura, et al., 2016). The work greatly benefitted from a recent European proficiency test with 120 laboratories measuring radioactivity in maize (PT IX, Page 18 in Proficiency Tests (PTs) overview report).
- 14 April 2021