ICP AES determination of platinum group elements and gold in collective extract and strip product solution in analysis of geological samples

Abstract

ICP AES techniques for the determination of all platinum group elements (PGEs) and gold in extract and collective strip product solution have been developed on the basis of the interrelation between the main stages of the analysis. The ICP AES permissible contents of base metals interfering with the PGE and gold determination have been established. The extraction system (a mixture of p-alkyl aniline with petroleum sulfides in o-xylene or in the post-xylene fraction) is shown to be applicable to ICP and ensures a 10– to 20–fold concentration of PGEs and gold and the required (10⁶) degree of decontamination of the extract from the matrix elements. A new two-step method for a collective back extraction of PGEs and gold with ammonia and thiourea solutions is proposed. The validity of the techniques is confirmed by the analysis of six standard samples and by the agreement of the results with those obtained by the independent ETAAS method. The techniques were tested on raw materials and copper-nickel plant products to determine all PGEs, including osmium, and gold over the range of their contents from 10⁻⁷ to 10⁻⁴%.