Spectrophotometric determination of rhenium as perrhenate by extraction with amiloride hydrochloride

Rhenium (0–20 μg) may be determined as perrhenate spectrophotometrically at 362 nm after its extraction at pH 4 with amiloride hydrochloride into 4-methyl-2-pentanone. The relative standard deviation for 7 determinations of 10 μg of perrhenate is 1.5%. The effects of pH and diverse ions are reported. Only perchlorate, periodate and iodide interfere seriously. The system has been applied to the determination of rhenium on alumina and on carbon catalysts.