engleski

Electrochemical properties of thiometalate anions (SbS43-, MoS42-)

Biologically active trace elements include elements that in moderate quantities are beneficial to organisms (e.g. V, Fe, Ni, Cu, Zn, Mo) and elements that are hazardous (e.g. As, Ag, Cd, Hg). Sulfide reacts with biologically active trace elements in opposing ways, stabilizing both insoluble sulfide minerals and soluble aqueous species (1-4). In nature, the major concern is the possibility of soluble sulfidic forms of hazardous elements. Sulfidic conditions, common in many environments (lake, rivers, landfills), might facilitate return of hazardous elements to the acitive biosphere. In sulfidic solution a number of oxyanions (MoO42-, AsO33-, AsO43-, SbO33-, VO43-) are known to exchange one or more O atoms for S atoms. As a result, a variety of soluble thiometalate anions exisst. These anions, due to the presence of 2 or more S atoms, could act as multidetate, soft chelating agents (3, 5). They could be effective transportating agents for soft cations such as Cu(I), Ag(I) and Hg(II). Here we discuss the electrochemical behavior of thiometalates, SbS43- and MoS42-, at the HMDE in order to establish analytical possibilities for its determination in mixtures with sulfide species.

thiometalates; voltammetry

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