INTER-LABORATORY COMPARISONS - DETERMINATION OF ACTINIDES IN EXCRETA

Inter-laboratory tests are a means of assessing the analytical coheren ce of medical laboratories. In radiotoxicology, this kind of exercise makes it possible to keep up with laboratory know-how and with the evo lution and relative performances of analytical techniques (precision a nd reproducibility). However, the goal of the laboratories taking part in these annual exercises is not only to check the accuracy of their results. The analytical discussions and the chance to compare experien ces enrich the group's general competence. French biologists have been organizing annual radiotoxicology intercomparison exercises since 197 8. The exercises are carried out within the framework of a working gro up (GT1) operating under the aegis of the French Atomic Energy Commiss ion's (CEA) Medical Coordinator. Using reports and diagrams which pres ent the results obtained by the participants ih the form of syntheses, the authors describe how the exercises for determining actinides in e xcreta (urine and faeces) are organized, how the results are evaluated in terms of the analytical methods used, and the improvements made in analytical and metrological performance. Up until 1985, these exercis es were limited to French laboratories. Since then, the exercises have acquired an international dimension, opening up to include interested foreign radiochemists, initially from European laboratories, and now From laboratories worldwide. At the present time, 35 laboratories repr esenting 9 countries lake part regularly in these intercomparison exer cises.