IAEA quality control study on determining trace elements in biological matrices for air pollution research

Analysis of lichens and mosses were routinely performed by 17 laboratories from 15 countries around the world, participating in a project coordinated by the International Atomic Energy Agency (IAEA). To improve and control the quality of such determinations, the IAEA organized a two-round interlaboratory exercise, which allowed the detection and removal of most of the pitfalls observed in the determination of 27 elements. The application of instrumental neutron activation analysis helped reveal poor recoveries in some laboratories due to incomplete digestion for a number of elements. The exercise emphasized the importance of achieving comparability of chemical measurements to a recognized reference.