Spectrophotometric and ESR methods of rhenium determination based one electron photoreduction of Re(VII)

A possibility of photochemical reduction of Re(VII) to Re(VI) in mixture of concentrated sulfuric and hydrochloric acids has been demonstrated. The reaction mechanisms of Re(VII) photoreduction and ReVIOCls- complex decay have been considered from view point of acids and water content. The optimal conditions of ReVIOCl5- stability have been found. Spectrophotometric and ESR methods of rhenium determination based on photochemical production of ReVIOCl5- complex with the detection of 1μg/ml have been proposed. Rhenium concentration in industrial sulfuric acid has been determined. (Author)