ANALYTICAL STRATEGY FOR THE CHEMICAL CHARACTERIZATION OF BIOLOGICAL REFERENCE MATERIALS

The analytical strategy for the elemental chemical characterization of biological reference materials followed during a recently completed R eference Material development endeavour is discussed. Characterization , the assignment of reliable values to total elemental concentrations of a wide range of elements, poses the most difficult challenge in the scheme of reference material (RM) production. A review is presented o f the many factors considered that significantly impinged on the condu ct and outcome of the complex analytical characterization exercise. Ma jor considerations were: (1) analytical elemental characterization phi losophy, (2) analyte selection, (3) selection of analytical methodolog ies, (4) statistical protocols, (5) in-house characterization, (6) ass essment of material homogeneity (7) cooperative interlaboratory charac terization campaign, (8)data evaluation and (9) calculation of concent ration values and associated uncertainties.