Non-destructive determination of silver in lead by neutron activation with a 227Ac-Be isotopic neutron source

A method has been developed for the determination of silver in lead by instrumental neutron activation analysis with the aid of a ²²⁷Ac-Be isotopic neutron source. The samples are irradiated for 60 s, allowed to decay for 10 s, and counted for 60 s. ¹¹⁰Ag can be measured free of interferences provided that copper and antimony do not occur in concentrations higher than ca. 1000 p.p.m. A calibration curve was established for silver concentrations between 0 and 4000 p.p.m. by means of standards prepared by melting together high-purity silver and lead under a hydrogen atmosphere. For 17.5-g lead samples, containing between 1000 and 2500 p.p.m. of silver, a mean relative precision of 0.8% was obtained after a 10-min analysis.