NUKLEONIKA 2006, 51(Suppl. 2):s27-s31

Only reliable analytical results can serve as a basis of meaningful evaluation and protection of the environment against radioactive contaminants. So, laboratories dealing with the environmental radioactivity determinations should regularly demonstrate their ability to produce acceptable results. Since 2002, every two years organization of national interlaboratory comparisons (ILC) on the determination of different radionuclides in food and environmental samples is required by the Polish law. The aim of the paper is presentation how test materials applied in the Institute of Nuclear Chemistry and Technology (INCT, Warsaw, Poland) for the 2004 ILC on the determination of ¹³⁷Cs and ⁹⁰Sr in water, food and soil were prepared.