Alkyl cyanide medium for the determination of precious metals by atomic absorption spectrometry

Abstract

Concentrations ranging from parts per billion levels up to a few parts per million can be adequately determined for platinum, palladium and gold pre-concentrated in a silver bead, when dissolved in an alkaline cyanide solution, by the use of AAS, with a vanadium buffer to correct for precious metal interference. The same medium is also proposed for the determination of silver, platinum, palladium and rhodium pre-concentrated in a gold bead; however, the rhodium recovery is poor. The difficulty in recovering rhodium is not associated with the medium of the final solution but rather with losses produced by the possible formation of lead rhodium oxide during cupellation and with the acid-insoluble flakes containing lead and rhodium.