Elemental speciation in biological fluids. Invited lecture

Abstract

Elemental speciation in biological fluids implies investigation of the bond between the trace element and available ligands, mostly proteins or low relative molecular mass compounds, as a basis for kinetic and metabolic studies. Strategies of procedures are outlined and attention is drawn to the many difficulties that can be encountered. These include the complexity of the matrix, insufficient specificity of separation of the biocompounds, fortuitous contaminations with trace elements, breaking-up of the original metal–protein binding. Identification and quantitative determination of the biocompounds to which the trace element is linked and accurate measurement of the trace element in the fractions are quintessential. This is illustrated with As speciation studies in rat urine and red blood cell lysate, and with Cr speciation studies in serum using radiolabels.