Determination of copper in zinc by proton activation analysis

A method for the determination of copper in zinc by proton activation analysis using the63Cu(p, n)63Zn reaction has been developed.63Zn has to be separated chemically from gallium and copper activities formed out of the zinc matrix and from indium activity formed out of cadnium impurity. Gallium radionuclides are retained on a cation exchanger in chloride medium and the residual activity is extracted in di-isopropyl ether. Copper and indium are subsequently extracted with cupferron in chloroform. The method was applied to BCR reference materials with a copper concentration at the μg.g−1 level. The detection limit amounts to 0.5 μg.g−1.