Spectrophotometric determination of trace amounts of selenium(IV) by catalytic kinetic method

Abstract

2315-2317A spectrophotometric method for the determination of selenium(IV) is described, based on the selenium(IV)-catalyzed oxidation of methyl blue with KBrO3 in nitric acid medium. As the redox reaction proceeds, the blue colour of the dye is decolourized. LogA0/A shows a good linear relationship with the amount of selenium. The detection range of the method is 0-5 μg dm-3 with sensitivity of 0.3527 μg dm-3. The system is selective as most of the cations, viz, copper, potassium, iron , etc. can be tolerated during the determination of Se(IV). The method has been used to determine Se(IV) in Chinese herbal drugs