[Reference materials and trace element analysis].

The use of appropriate reference materials allows the accuracy of analytical determinations to be assessed. The present availability of certified reference materials not always can adequately meet the needs of research in the field of trace and ultratrace element analysis, in particular as regards complex matrices, such as biological and environmental materials. In this context the various definitions of a reference material are discussed. Planning and certification of novel certified reference materials cannot disregard the exigency of obtaining more qualified information on the analytes, especially in so far as their different chemical species are concerned.