Precipitation of Platinum Metals by Organic Monosulfides. Determination of Platium with Thiophenol and Rhodium with Thiobarbituric Acid

Abstract

This report deals with a preliminary investigation of organic monosulfide compounds as analytical reagents for the platinum metals. The action of seven organic monosulfide compounds with some of the platinum and related metals is described. It has been found that rhodium may be determined gravimetrically with thiobarbituric acid. Thiophenol may be used as a precipitant in the gravimetric determination of platinum.

Inorganic Gravimetric Analysis

“…Because of the favorable •weight factor the author preferred direct weighing of aurous benzenethiolate to subsequent ignition with its accompanying objectionable odor. The authors who first recorded thiophenol as a reagent for gold (55) disapproved of the method because of the objectionable odor and the instability of the precipitant.…”

A Scheme for the Separation of Platinum, Palladium, Rhodium, and Iridium by Solvent Extraction.

“…This was prepared by dissolving Johnson and Matthey Specpure ammonium chlororhodite in a known volume of 1 7 hydrochloric acid. The solution was standardized gravimetrically with thiobarbituric acid (10).…”

New Fire Assay Method for Rhodium in Ores and Concentrates.

“…of \N hydrochloric acid. The rhodium content of this solution was determined gravimetrically with thiobarbituric acid (5) and was 1.10 Procedure. Preparation of Tin Assay Buttons.…”