Photometric Determination of Copper(II) by the Catalytic Action on the Reaction of Iron(III) Reduction with Thiosulfate Ion

A procedure is proposed for the kinetic determination of copper(II) by its catalytic effect on the reduction of iron(III) with thiosulfate ion, followed by the photometric detection of the destruction of iron(III) thiocyanate. The optimal reaction conditions were selected. The limit of determination of copper(II) is 0.06 mu g/cm(3); and the relative error of determination is 4%. The results are characterized by good convergence and accuracy. The procedure is applicable for the quantitative determination of copper(II) in water.