EN
Heavy metals migrate in thc environment in different forms (free ions, labile inorganic and organic complexes). Most of the heavy metals create a potential threat to organisms. Their harmfulness is connected not only with biological, biochemical properties, but also depends on forms in which heavy metals appear in the environment, so-called speciation. The chemical term speciation has several meanings and can be defined as analysis, distribution, bioavailability and transformation. In the presented paper the occurrence of heavy metals and possibilities of their determination are discussed. Using anodic stripping voltammetry (DPASV) it was found that 1 gram of humic substances (HS) dissolved in surface water bound to 13.7 μg Cu/g HS and 7.1 μg Pb/g HS. Stronger complexing properties were observed for HS isolated from groundwater: 27 μg/g HS in the case of Cu and 46 μg/g HS for Pb.