Quality of radionuclide analysis in environmental samples

To supply Brazilian needs in the field of quality of radionuclide analyses in environmental samples, the Institute for Radioprotection and Dosimetry of the National Nuclear Energy Commission (IRD/CNEN has begun a national intercomparison program (PNI) to encourage the development and optimization of analytical methodologies for radionuclide determination in environmental samples. Since its initiation, the PNI has promoted eight intercomparison runs involving 221 studies in a total of 485 analyses. These studies consist of the determination of different radionuclides in many kinds of environmental simulated matrices, like water, milk and filtered air. The total analytical performance reached by the 16 participant laboratories was: 73.7% good results (within all limits), 10.2% of results in the warning zone and 16.1% unacceptable results (out of the control limits). As was expected, the analytical performance of the laboratories had improved after their participation in the intercomparison runs, which emphasizes the importance of this cooperative work.