RESUMO
A method for determination of seleninm in foods by hydride generation -atomic absorption spectrometry was described. Food samples were digested by heating with a mixture of nitric, perchloric, and sulfuric acids. After addition of 4ml of 6mol/L HC1, the digests were heated in a boiling water bath to reduce selenate to selenite. The hydride of selenium was evolved by reduction with 1% KBH4 from a system of 2mol/L HC1-1% K3Fe(CN)6 and then atomized in a laboratory-constructed electrically heated silica absorption tube. Absolute detection limit of the method was 2ng and the linear range was from 0 to 10 ng/mlSe. Recoveries of inorganic selenium added to a variety of foods ranged from 83% to 112%. Accuracies checked with standard materials of pig liver and brassica oleraca were within the certified values. The loss and pollution of selenium during the sample pretreatment were also studied.