USE OF 2 IAEA INTERCOMPARISON STUDIES TO ASSESS THE APPROPRIATENESS OF MODERN ANALYTICAL METHODS

Intercomparison studies provide a useful approach to characterise cand idate reference materials and provide a tool to assess the performance of laboratories, instrumentation and sample work-up protocols, The IA EA organises intercomparison exercises for trace elements in a range o f matrices which attract the participation of a large number of labora tories from around the globe, Participants are free to choose their ow n analytical strategy and therefore a wide range of digestion procedur es and analytical methods are represented, A statistical assessment of the data obtained by up to 158 laboratories for six elements (Al, Fe; Se, Cd, Hg and Pb) representing 'easy', 'problematic' and 'challengin g' analytes during two IAEA intercomparison studies on biological matr ices, MIST SRM 1570a Spinach and a candidate reference material, IAEA- 359 Cabbage, is discussed, The elemental concentrations for the elemen ts studied range from the ng g(-1) to the fraction of a percent level.