The Determination of Osmium

Résumé du livre

The direct distillation of osmium from a tin button proved unsuccessful. A method used by Williamson and Savage for the determination of osmium in osmiridium was adapted for the recovery and determination of osmium collected in a nickel sulphide button. The collector button was dissolved in hydrochloric acid, and the osmium was filtered off. After the osmium had been fused with sodium peroxide, it was distilled as the tetroxide, and the concentration of the noble metal was measured spectrophotometrically as the thiourea complex. This procedure gave recoveries of about 90 per cent. The coefficient of variation of the method at the 20 ug level was 6 per cent for the analytical procedure and 10 per cent for the recovery of osmium from a sample of ore. The range covered without dilution was 2 to 40 ug of osmium. The detailed laboratory method is given as an appendix to the report.