Multi-element pre-concentration by solvent extraction compatible with an aqua regia digestion for geochemical exploration samples

Abstract

The interference of nitric acid in the organic solvent extraction of metal iodide complexes as ion associates with the trioctylmethyl ammonium ion was investigated. The results show that the interference is caused by nitric oxide extracted into the organic solvent in the form of nitrosyl compounds and that this can be eliminated by the addition of sulphamic acid or urea. A multi-element extraction procedure was applied to geochemical exploration samples digested with aqua regia. Ag, Cd, Se, Te and Tl were determined by AAS in the extracts down to 100 p.p.b. levels.