Determination of Selenium Content in Soil and Parent Material by HG-AAS

摘要

HG-AAS (Hydride generation coupled with atomic absorption spectrometry) was applied to assess selenium concentrations in some soil and parental material samples from South-Eastern Romanian Plain and Central-South Dobrogea. Selenium analysis by HG-AAS requires digestion of solid samples to release selenium into a solution, and extraction of mobile selenium content with a common extraction solution, namely EDTA with Ammonium Acetate. Traditionally, wet acid digestion has been used which involves digestion/heating with strong acids to destroy the organic matter and dissolve the metal ions. The proposed procedure involves microwave sample preparation by using a mixture of HpjHNOJHCl. Parameters for the reduction ofSe (VI) to Se (IV) in HCl medium by heating in a microwave oven have been optimized. These contents were determined by atomic absorption spectrometry coupled with hydride generation (HG-AAS). The concentrations of selenium are within the allowed limits, even lower. Certain parameters of the method were validated for selenium content determination from soil and plant samples by atomic absorption spectrometry coupled with hydride generator: the working concentrations, linearity, detection limit, quantification limit. Data obtained regarding selenium content confirms its deficiency in the studied area.