A Facile Catalytic- Kinetic Method for The Determination of Selenium (IV)

A catalytic-kinetic method for the determination of selenium is proposed. Alizarin navy blue is reduced by sodium sulfide to from a colorless product. The reaction is accelerated by trace amounts of Se (IV), and can be followed by measuring the decrease in absorbance of the dye at 620nm and 30 °C by the fixed time method. Selenium can be determined in the range of 0.004 — 0.12 1.1g.m1-1 . The detection limit is 0.03 ng.m1-1 Se (IV). The relative standard deviation for 0.08, and 0.11,tg.m1-1 : Se (IV) was 2.2%, and 1.8%, respectively. The method is free from most interferences and it was applied to determination of selenium in water real samples.