Effects of fusion charge composition on the determination of platinum group elements using collection into a minimized nickel sulphide button

✍ Scribed by Tomáš Paukert; Ivan Rubeška

• Publisher: Elsevier Science
• Year: 1993
• Tongue: English
• Weight: 846 KB
• Volume: 278
• Category: Article
• ISSN: 0003-2670
• DOI: 10.1016/0003-2670(93)80091-x

✦ Synopsis

For characterizing fire assay fusion and the collection of platinum group elements (PGE) into a NiS button, two parameters referring to the charge before fusion were defined . One is the extraction ratio E, expressed as the mass ratio of the sample plus flux to the collector (Ni + S) and the other is the sulphur content in the collector Sc, expressed as a percentage. Using graphite furnace atomic absorption spectrometry after fire assay into a minimized NiS button, the PGE recoveries were investigated when varying these two parameters . The experimental data show that for an acceptable recovery, SC may vary in a fairly broad range, namely 30-50% . Any excess of sulphur seems to be easily removed during fusion by oxidation with atmospheric oxygen. For full recovery, an extraction ratio E 3 30 is admissible. However, at high extraction ratios the sample composition, particularly its sulphur content, becomes highly critical and sulphur must be taken into account when preparing the fusion charge . The precision and accuracy of the recommended procedure were tested on ten reference materials . The comparison of the results with those of SARM-7, which is used by most analysts, was favourable . There is a need for many more analysts to report their results before "usable values" can be established for other reference materials and statistical tests can be done .