Radioactivation Analysis of Zinc Based on the Quantitative Isotope Dilution Principle

Trace amounts of zinc were determined by the radioactivation analysis based on the quantitative isotope dilution principle. The irradiated sample is divided into two parts, and a known amount of carrier M is added to one. An amount m which is less than the amount of the element in question Mx is separated from each part, and then radioactivities of both parts a and a' are measured. The unknown amount Mx is calculated from Mx=a'M/ (a-a') The experiment to determine the reaction ratio between zinc and dithizone was carried out at various conditions and it was observed that the ratio was constant in the solution of pH 8.5. It was also shown that the specific activity was proportional to the amounts of zinc added, and the reproducibility of the results was satisfactory. Then, this method has been applied to the determination of zinc in the zinc doped gallium arsenade as semiconductor material and satisfactory results were obtained.