SIMULTANEOUS DETERMINATION OF COPPER, LEAD, CADMIUM, AND ZINC IN PREVIOUSLY LYOPHILIZED BIOLOGICAL TISSUES USING FLOW-INJECTION ANALYSIS ANODIC-STRIPPING VOLTAMMETRY

Improvements in three main aspects of the analysis of metal traces in biological tissues are proposed, namely: (a) lyophilization of the sam ples both to preserve them and to favor the digestion process; (b) dig estion of the lyophilized tissues using an effective and fast procedur e; and (c) automatic determination of the target analytes b) flow-inje ction analysis/anodic stripping voltammetry (FIA/ASV). After optimizat ion of these steps. the overall procedure was successfully applied to the simultaneous determination of copper, lead, cadmium, and zinc in c ertified reference materials (CRMs) and fresh bovine liver samples wit h good results. Finally, the performance of the method was validated b y a statistical study using parameters of the certification campaign o f the CRMs; the results obtained being within, or close to, the confid ence levels of the certification campaign.