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 frui t juices by electrothermal atomization atomic absorption spectrometry is proposed. The flow manifoid used, which is coupled to the autosampl er cup, enables dilution of the slurry, addition of a chemical modifie r and the determination of Se in the filtered liquid phase. The effect s of various chemical modifiers, furnace temperatures and major foreig n ions present in fruits were investigated. Selenium was successfully determined in fruit and tomato juice by using the standard additions m ethod (juice samples were diluted 10-fold) with a relative standard de viation of 4.5-12.0%. The limit of detection (3s(b)) of the proposed m ethod is 5 mug l-1.