Challenges from speciation analysis for the development of biological reference materials

Starting with explanations for the increasing demand for speciation analysi s the need of appropriate certified reference materials is justified. Speci fic aspects of biological reference materials for speciation QA/QC are disc ussed from the point of view of the total analytical process. Examples of u nwanted species transformations during analysis are given and critical anal ytical steps are highlighted. Unchanged biological materials as CRMs and ap propriate pure standard compounds are indispensable for the further develop ment of this analytical field.