The importance of inorganic selenium and chromium speciation at low concent
ration levels is well established. Thus, society demands that accurate anal
ytical methods be implemented in routine laboratories. In this context, the
European Commission, through the Standards, Measurements and Testing Progr
amme, has contributed significantly to improving the quality control of the
speciation of inorganic selenium, as Set (IV) and Se(VI), and chromium, as
Cr(III) and Cr(VI), by organising interlaboratory studies followed by the
preparation of candidate reference materials. In this article are outlined
the performance of the methods used by the participating laboratories and t
he main sources of errors detected. (C) 2000 Elsevier Science B.V. All righ
ts reserved.