Simultaneous determination of the speciation of selenium and tellurium in geological matrices by use of an iron(III)-modified chelating resin and cathodic stripping voltammetry

The paper describes the combined use of a preconcentration method using a chelating resin (iron(III)-loaded) and cathodic stripping voltammetry to determine simultaneously the speciation of inorganic Se and Te in solid environmental matrices. The method, whose reliability has been checked on certified reference materials (NIST), is suitable for studying natural levels (down to μg Kg−1), easy to apply and also characterised by good precision. The speciation method has been applied to six geological reference samples (GXR series) kindly supplied by the U.S. Geochemical Survey.