Quantitative Determination Of Copper Research Articles

Quantitative Determination of Copper in Natural Rubber

Abstract A procedure is recommended in which small amounts of copper in rubber can be measured quantitatively by determining the depth of color of a copper carbamate complex in a carbon tetrachloride solution. The complex is formed in an alkaline solution prepared from an acid extract of the rubber ashed at 550° C. This procedure yields results which are as reliable as those obtained by the more tedious and time-consuming procedures involving the wet-oxidation process which are at present recommended by standardizing organizations. The use of an organic solution rather than an aqueous suspension gives better reproducibility, permits easier use of a photometer, and reduces the interference due to iron by a factor of ten.

Quantitative determination of copper, cuprous oxide and cupric oxide in a mixture

Advantage is taken of the solubility of cuprous oxide in hot saturated solution of potassium iodide in which metallic copper and cupric oxide are insoluble. The residual mixture of metallic copper and cupric oxide is then treated with acidified ferric chloride and the ferrous iron corresponding to the metallic copper titrated with dichromate or ceric sulphate.