Rhenium was determined spectrophotometrically after extraction of its complex with 5-chloro-2-hydroxythiobenzhydrazide into molten naphthalene from 0.4-3.5 M hydrochloric acid medium.Beers law was obeyed in the concentration range 2.0-20.0 ppm of rhenium in a chloroform solution at 580 nm.The molar absorptivity and Sandell sensitivity were 0.931 X 10~4 1 mol~(-1)cm~(-1)and 0.02 ppm,respectively.Six replicate analyses of a solution containing 8.0 ppm of rhenium gave a mean absorbance of 0.405 with a standard deviation of 0.0035 and a relative standard deviation of 0.86.The complex was stable for over 24 h.The metal-to-ligand ratio in the complex was 1:3.Interference from various ions was studied,and the method was applied to the determination of rhenium in various alloy samples.The method permits the sequential separation and determination of ruthenium,rhenium and osmium from their Mixtures.
展开▼
