Comprehensive Analysis of Precious Metals in some Geological Standards by Flameless A.A. Spectroscopy

Abstract

Precious metals (Ag, Au, Pt, Pd, Rh) were determined by flameless absorption atomic spectrornetry. Aqua regia sample decomposition followed by Te coprecipitation was employed to preconcentrate the precious metals in geological materials. With 5 g sample take‐up, the limits of determination were 1‐2 ppb for Au, Pd and Rh, 5 ppb for Ag and 10‐20 ppb for Pt. These elements were determined in some geochemical standards.

Flameless Atomic Absorption Determination of Gold and Palladium in Geological Reference Samples

“…This work confirms also the conclusion presented by Signiholfi et al (9) that a partial attack with aqua regia usually ensures almost the total solubilization of precious metals (at least for gold and palladium) from geological materials.…”

Solubility of Pt and Pd sulfides and Au metal in aqueous bisulfide solutions

“…The method of co-precipitation with Te (Fryer and Kerrieh 1978;McHugh 1983;Sighinolfi et al 1984) was found to be effective and satisfactory to pre-concentrate Pt, Pd and Au, and to isolate them from the sample matrices. Hydrogen sulfide was instantly converted into NariS by reaction with NaOH.…”

Analytical techniques for the determination of precious metals in geological and related materials

“…After the gold is solubilized its separation from matrix elements is achieved by solvent extraction into methyl isobutyl ketone (MIBK), 36,37 co-precipitation on tellurium 38 or mer- cury 39 to avoid interferences at the measurement stage and to effect preconcentration. Using a 2 g sample Balaram et al 30 reported a rapid multi-acid digestion procedure utilizing mixtures of AR, Br 2 , HF, HClO 4 and H 2 O 2 which is amenable for batch analysis.…”