Solvent extraction-atomic absorption determination of selenium in waters, plants, and soils

A method was developed for determining total selenium in natural and waste waters, plants, and soils by graphite furnace atomic absorption spectrometry, Selenium was preconcentrated from 2- to 40-fold using the selective extraction of selenium with l-hexene from a perchlorate-bromide medium as an organoselenium compound. The accuracy of the method was confirmed by an analysis of standard reference materials, by a comparison of the results of analyzing samples by the method developed and by an independent one, and by the added-found method. The relative standard deviation for the determination of 0.01-2 mu g/g (0.4-360 mu g/L in waters) of selenium was 2-15%. The detection limit of selenium (3 sigma-test) was 0.01 mu g/mL, which, for an extract volume of 2.5 mt, a sample weight of 5 g, or an aliquot portion of the water sample of 200 mt, corresponds, respectively, to 0.005 mu g/g and 0.1 mu g/L.