Neutron activation analysis of traces of gold in pure silver using sulfur as a preconcentration agent

In this method for the determination of traces of gold in silver, the sulfur produced by decomposition of silver (matrix) sulfide precipitate with nitric acid was used as a preirradiation concentration agent. As the activated sulfur does not interfere with the γ-ray spectrometry, the γ-radioactivity of¹⁹⁸Au in the activated sulfur sample was counted directly with a Ge(Li) detector without post-irradiation chemical treatment. The chemical yield of gold was more than 99%, and the concentration factor was 5–6·10³. The analytical results of gold in 99.9 and 99.999% silver were 1.6–2.5 and 0.015–0.024 ppm, respectively.