Determination of silver, gold and palladium by a combined fire-assay atomic-absorption procedure

A method is described which combines the best features of the fire-assay procedure with an atomic-absorption technique. The precious-metal bead resulting from the fire-assay concentration step is dissolved in acids, the solution evaporated to dryness and the residue dissolved in b measured quantity of cyanide solution. The atomicabsorption measurement of this solution allows the determination of as little as 0.017 ppm of silver, 0.08 ppm of gold, and/or 0.08 ppm of palladium in various precious-metat-bearing materials with a precision of +/- 1%.