The determination method of selenium (IV) in water samples by graphite furnace atomic absorption spectrometry (GF-AAS) after pre-concentration with bacteria was developed. High Se (IV) -absorbing ability was found in
Bacillus sp. which was separated from specific microbes for wastewater treatment systems. Precipitated bacteria was dissolved with 0.7ml of HNO
3 (30%) and 0.3ml of palladium solution (1000mg/l) . The dissolved solution was injected into the graphite tube and Se peak height was measured under the optimum GF-AAS operating conditions. No interfering effects were found for coexisting 100μg/l of various metal ions on the l0μg/l of Se (IV) analysis. On the other hand, the depressant effects were caused by 1000μg/l of metal anions. By the proposed method, 0.5-30μg/l of Se (IV) could be quantitatively recovered and determined with the relative standard deviation of 2.2%. This method was applied to the determination of Se (IV) in wastewaters and the results were in good agreement with them by the Cu-DDTC coprecipitation/GF-AAS method. Pre-concentration of Se (IV) from gas washer wastes was not possible with this method due to the high salinity of the solutions.
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