REACTION OF RHENIUM WITH METHYL VIOLET

It is shown that rhenium in the form of perrhenate forms a complex with methyl violet, which may be extracted by benxol and toluol. The optimal pH value for the extraction is 3.5 to 5. The absorption spectrum of a solution of the perrhenate complex with methyl violet in toluol was studied. The solution of this complex proved to have three maxima: 330 m mu ( epsilon = 229,500), 540 an mu ( epsilon = 28,000), and 600 m mu ( epsilon = 39,500). The sensitlvity of the reaction to pure salts proved equal to 0.1 mu g/ml of rhenium. The presence of a 40-fold qunntity of molybdenum in respect to rhenium does not hinder the reaction. A large quantity of molybdenum lowers the sensitivity of the reaction. The color intensity of a toluol solution of the rhenium complex with urethyl violet is proportional to the rhenium content and, therefore, the extracted complex of perrhenate with methyl violet may be applied for the colorimetric determination of rhenium. (tr-auth)