INVOLVEMENT OF ANALYTICAL-CHEMISTRY IN CHEMICAL SPECIATION OF METALS IN CLINICAL-SAMPLES

The different chemical species of the trace elements in a living syste m are determinants for their physiological behaviour. Their study is n ecessary to improve the understanding of trace element kinetics and me tabolism. In a complex matrix, such as biological fluids and tissues, some trace elements will occur as free or mononuclear ions; others as low molecular weight complexes, as reversible or irreversible macromol ecular complexes. Speciation investigations entail the separation of t he compounds, followed by the measurement of the trace element in the different fractions. Framework-procedures are outlined and attention i s drawn on the many difficulties that carl be encountered. These inclu de the complexity of tile matrix, insufficient specificity of the sepa ration of biocompounds, fortuitous contaminations with trace elements, and cutting the original metal-protein binding. State of the art desc ription is given for the speciation studies of Al, As, Cd, Cr, Co, Cu, Hg, Ni, Pb, Pt, Se, Sn, and Zn.