The determination of scandium and gold in meteorites, tektites and standard rocks by neutron activation analysis with an internal-reference method

Abstract

An internal-reference method has been established for the determination of scandium and of gold by neutron activation analysis, with calcium and platinum, respectively, as the reference elements; the method has been applied to the determination of both elements in several materials of geochemical origin. The composite γ-ray spectra of scandium and gold activities arising from scandium and gold in a sample and from the element used as reference by the (n,γ) reaction followed by β --decay are measured. The results can be calculated on the basis of the activity ratio of the two species in terms of the photopeak areas. The success of the method depends on chemical separations and on the high resolving power of a lithium-drifted germanium detector. Sensitivity and accuracy were assessed by analyzing synthetic mixtures of known composition. The proposed method was verified to be accurate for both elements even at p.p.b. levels. The Bruderheim and Canyon Diablo meteorites, Indochinite tektite, and standard rocks, G-I, W-I and JG-I were tested.