Determination of indium in metallic tin and cadmium by substoichiometric neutron activation analysis

The paper describes the determination of indium in tin and cadmium metals by the direct method, which is a variant of substoichiometric radioactivation analysis. It is based on substoichiometric extraction of indium diethyldithiocarbamate into carbon tetrachloride. Indium in tin metal was determined by sup(116m)In (T = 54 min), while sup(115m)In (T = 4.5 h) formed by the reaction 114Cd(n, γ)115Cd was used for cadmium samples. The irradiated sample was dissolved and the radioactivity of sup(116m)In or sup(115m)In (A) was measured. After the separation of indium from the matrix, a known amount of indium (m) was separated substoichiometrically and the radioactivity (a) was measured. Indium was calculated as Msub(x) = m.A/a. If a known amount of the element (M) is added to the irradiated sample in advance, the equation for calculation is given as Msub(x) = m.A/a - M. By this method, indium can be determined without any consideration of self-shielding and secondary nuclear reaction of the matrix. Tabulated data are given. (T.G.)