DETERMINATION OF SELENIUM IN FRUIT JUICES BY FLOW-INJECTION ELECTROTHERMAL ATOMIZATION ATOMIC-ABSORPTION SPECTROMETRY

An automatic flow injection method for the determination of Se in fruit juices by electrothermal atomization atomic absorption spectrometry is proposed. The flow manifoid used, which is coupled to the autosampler cup, enables dilution of the slurry, addition of a chemical modifier and the determination of Se in the filtered liquid phase. The effects of various chemical modifiers, furnace temperatures and major foreign ions present in fruits were investigated. Selenium was successfully determined in fruit and tomato juice by using the standard additions method (juice samples were diluted 10-fold) with a relative standard deviation of 4.5-12.0%. The limit of detection (3s(b)) of the proposed method is 5 mug l-1.