Determination of Selenium in Milk Powder by Atomic Absorption Spectrophotometry

Abstract

Determination of selenium in milk powder was carried out by atomic absorption spectrophotometry attached with a selenium hydride generation apparatus. About one g of sample was wet-ashed at 100-150°C on a hot plate in the presence of perchloric acid and nitric acid. To the digested solution stannous chloride and zinc slurry were added, and selenium hydride was generated, and the gas was conducted to the atomic absorption spectrophotometer. The absorbance was proportional to selenium hydride over a wide range of its content. This method was successfully applied to the determination of the selenium content of commercial milk powders by the values obtained which were within 0.04-0.12 ppm.