Premium
Comparison of Silver and Gold Inquarting in the Fire Assay Determination of Palladium/Platinum and Rhodium in Geological Samples
Author(s) -
Suominen Meeri,
Kontas Esko,
Niskavaara Heikki
Publication year - 2004
Publication title -
geostandards and geoanalytical research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.037
H-Index - 73
eISSN - 1751-908X
pISSN - 1639-4488
DOI - 10.1111/j.1751-908x.2004.tb01049.x
Subject(s) - rhodium , palladium , platinum group , platinum , chemistry , homogeneity (statistics) , base (topology) , analytical chemistry (journal) , inductively coupled plasma , mineralogy , metallurgy , materials science , chromatography , catalysis , plasma , mathematics , physics , mathematical analysis , biochemistry , statistics , quantum mechanics
The classical lead fire assay is still the most important method for the pre‐concentration and separation of Ag, Au and some of the platinum‐group elements (PGE) in the analysis of geological materials. The most frequently used fire assay procedure is the determination of Au, Pd and Pt with Ag as collector. When Au is used instead of Ag as a collector, Pd, Pt, Rh and possibly Ir can also be determined. In this study the recoveries by Au and Ag collectors, also called inquarts, were compared in the fire assay analysis of Pd, Pt and Rh in geological reference materials. The amount of gold to be added was optimised. Variable recoveries were obtained with Ag inquart for Rh, but a 2 mg inquart of Au gave good recoveries for all three of these elements in the analysis of reference samples of different geological materials. A procedure, alternative to scorification, to overcome interferences caused by base metals in the cupellation step is presented. The procedure involves cutting the Pb button into pieces and analysing the pieces separately. Prior to this, a homogeneity study of the lead button was made, and it showed that Pd, Pt and Rh were evenly distributed in the Pb button. All determinations were made using inductively coupled plasma‐atomic emission spectrometry (ICP‐AES).