Determination of Silver in Lead Concentrates by Atomic Absorption Spectroscopy

Abstract

THE fire assay method is used universally for the determination of silver in ores and concentrator products. This method, which is capable of very high, precision, is subject to a loss of silver during cupellation, and corrections for this loss, if made, must be on an empirical basis depending on the conditions of cupellation^1–3. Walsh⁴ showed that atomic absorption spectroscopy offered possibilities as an absolute spectrochemical method freed from the necessity of using chemically analysed standards or synthetic samples the composition of which approximated that of the unknown. Several papers^5–7 on the application of atomic absorption spectroscopy to the determination of cations in solution have been published. These papers showed that, in general, the atomic absorption technique was free from interelement effects and required the minimum amount of manipulation. Lockyer and Hames⁸ directed attention to the possibility of determining the noble metals by atomic absorption spectroscopy and quoted a limit of detectability of 0.1 p.p.m. for silver.