A critical study of Brilliant green as a spectrophotometric reagent: the determination of perrhenate and gold

Abstract

The spectrophotometric methods for determining rhenium and gold with Brilliant green have been re-examined in an investigation of the effects of purity of reagent and acidity on the precision and accuracy of results. The perrhenate-Brilliant green ion-association complex is extracted from a solution at pH 6, and is unaffected by reagent purity. The extraction of the tetrachloroaurate(III)-Brilliant green ion-association complex is carried out from 0·5 M hydrochloric acid solution, however, and an impure reagent gives low recoveries. Procedures are recommended for the determination of rhenium and gold, and the purification of the reagent is discussed.