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 samples both to preserve them and to favor the digestion process; (b) digestion of the lyophilized tissues using an effective and fast procedure; and (c) automatic determination of the target analytes by flow‐injection analysis/anodic stripping voltammetry (FIA/ASV). After optimization of these steps, the overall procedure was successfully applied to the simultaneous determination of copper, lead, cadmium, and zinc in certified reference materials (CRMs) and fresh bovine liver samples with good results. Finally, the performance of the method was validated by a statistical study using parameters of the certification campaign of the CRMs; the results obtained being within, or close to, the confidence levels of the certification campaign.