Determination of rhenium in rhenium-tungsten alloy

Abstract

The author has determined the adequate conditions for stable color-development in the reaction of rhenium with dimethylglyoxime and stannous chloride in the rapid determination of rhenium in rhenium-tungsten alloys by dimethylglyoxime method. Analytical procedure are as follows : 7.5 ml of 30% citric acid solution is added to alkali-fused solution of sample (10ml) in a 250ml volumetric flask, followed by additions of 2.5ml of 12N hydrochloric acid solution, 6ml of 1% dimethylglyoxime solution, 5ml of 25% stannous chloride solution, and it is finally made up to 250ml with 3N hydrochloric acid. After 5 minutes, the absorbance was measured at 462mμ.
Tungsten does not interfere in the existence of citric acid, while nickel, iron and molybdenum interfere in concentration more than 2mg/250ml. Interference by iron, however, is removed by reducing Fe³⁺ to Fe²⁺ with stannous chloride. The error in the proposed method is less than ±1.0% and the method was applied for the routine analysis of rhenium-tungsten alloys.