Collection of copper(II) with dithiocarboxyaminoethylcarbamoylcellulose

Abstract

The collection of copper(II) from 50 ml of 1×10^-5M copper salt solution was attempted with 0.1g of dithiocarboxyaminoethylcarbamoylcellulose (D-cell) prepared by the present authors. A satisfactory recovery of copper (II) was achieved over the range of pH 1.3 to 5.9 by stirring the solution together with the D-cell for 30 min at room temperature. Although dithiocarbamate, carboxyl and aminoethylcarbamoyl groups have been introduced to the D-cell as the functional groups, only dithiocarbamate groups seemed to participate to the retention of copper (II) from a solution of pH below 2.0. The collection of copper (II) from 1 M sodium nitrate solution and also from 1 M calcium nitrate solution at pH 4.6 to 4.8 was satisfactorily complete. The optimum pH range was shifted to 1.9 to 5.9 when the collection was done from 1 M sodium chloride solution. The collection of copper(II) was also achieved from 0.1 M sodium bromide solution and from 0.01 M sodium iodide solution at pH 5.0 to 5.3. Various complexing agents such as citrate, cyanide, thiocyanate and EDTA were found to interfere the collection of copper with the D-cell; especially in the presence of cyanide no retention of copper (II) on the D-cell was allowed even at a low concentration of 0.001 M. In the present work, therefore, 0.1 M potassium cyanide solution was effectively used to desorb or release copper(II) from the D-cell after the collection. For example, 63.6μg of copper(II) was desorbed quantitatively from the D-cell by stirring it in 10 ml of 0.1 M pottasium cyanide solution for 30 min at room temperature. Other heavy metals such as manganese (II), cobalt (II), nickel (II) and zinc (II) were not collected on the D-cell at pH 4.0, and therefore, copper(II) can be separated from these metal ions by the treatment with the D-cell in the range of pH 1.3 to 4.0.