Spectrophotometric determination of rhenium with dithio-oxamide in strongly alkaline medium

The interaction between rhenium(VII) and dithio-oxamide in strongly alkaline medium in presence of tin(II) chloride as reluctant has been studied. A purple complex is obtained, with lambda(max) 526 nm and (max) = 4.0 x 10(3) l.mole(-1).cm(-1). The reaction has been applied to the determination of rhenium in tungsten-rhenium alloy after its anodic electrochemical dissolution in alkaline medium. A 1000-fold excess of molybdenum or tungsten does not interfere. A modification of the proposed method can be used as a spot-test for rapid control of rhenium content in industrial solutions.