Ion-exchange resins containing s-bonded dithizone and dehydrodithizone as functional groups : Part 3. Determination of Gold,Platinum and Palladium in Geological Samples by means of a Dehydrodithizone Resin and Plasma Emission Spectrometry

A procedure is described for the determination of gold, platinum and palladium in sulphide ores, concentrates and mattes. The method is based on chromatographic separation and selective elution of precious metals on small resin beds (0.7 × 2.5 cm) of the sorbent P-TD. After roasting, the samples were digested with aqua regia, and the residues fused with sodium peroxide. The acid leaching solutions obtained from both procedures were separately passed through an ion-exchange column. The metals were quantitatively retained after one loading step and eluted by a sequence of 2 M perchloric acid and 5% (w/v) thiourea solution. Preconcentrated Au, Pt and Pd were finally quantified with a d.c. plasma emission spectrometer. The effect of roasting temperature on the recovery of precious metals as well as the efficiency of the aqua regia leaching from the different materials were investigated in detail. Repeated analyses of standard reference samples proved the proposed method to be reliable.