RESUMO
The amounts of total selenium and Se-species including organic and inorganic selenium in vegetables were measured with the method of hydride generation-atomic fluorescence spectrometry. The instrumental parameters and analytical conditions were optimized. In order to obtain the maximum fluorescence signal, the effects of the concentrations of HCI and KBH4 in carrier solution, the concentrations of HCl and HNO3 in sample medium, and the interference from foreign ion (Cu) on the signal were mainly investigated. Under the optimum conditions, the detection limit estimated with 3-fold standard deviation by 11 replicates of procedure blank was 0.35 ng x g(-1). The recovery tested by adding standards ranged from 97.6% to 101%. After being digested with HNO3 by microwave, selenium in several kinds of vegetables was measured. The results indicated that the total amounts of Se in the vegetable samples were low except straw mushroom, in which the content of Se was 0.151 microg x g(-1) (dry weight). In addition, the species of organic selenium were the main existing forms in vegetables.
