Determination of rhenium by a combination of reversed-phase chromatography and ultraviolet spectrophotometry

Ultraviolet spectrophotometric determination of perrhenate ion is the simplest method for rhenium, but the method is subjected to interference from many ions which exhibit their absorption in the ultraviolet.By a reversed-phase column chromatography with tributyl phosphate-Teflon, perrhenate ion is separated from these ions, particularly molybdenum, and the method can be applied satisfactorily. The column with 6 mm in inside diameter is packed with 1 g of Teflon supports impregnated with 1 ml of tributyl phosphate and equilibrated with 10 ml of 1 M sulfric acid solution. Acid concentration of the sample solution is adjusted about 1 M with sulfric acid and the solution is passed through the column. Molybdate and other metal ions are removed with 20 ml of 1 M sulfric acid solution, and the perrhenate ion is eluted with 25 ml of distilled water. The absorbance of the effluent is directly measured at 227 nm by means of flow cell (10 mm). The method is applicable to more than 20μg of rhenium in molybdenite concentrates and its flue dust. When the effluent is diluted to 25 ml in a volumetric flask and measured the absorbance with 10 mm cell, the method is applicable to more than 60μg of rhenium.