A micellar improved method for trace levels selenium quantification in food samples, alcoholic and nonalcoholic...

A useful preconcentration and determination method was proposed for trace selenium in food samples. The procedure is based on complex formation of Pyronine B with Se(IV) ions in the presence of sodium dodecyl sulphate (SDS) and Ponpe 7.5. The variables affecting complex formation, extraction and phase separation were studied and optimised. Under the experimental conditions used, the calibration graph was linear in the range of 20-1700 μg L(-1) for Se(IV) ions. The limit of detection was 3.81 μg L(-1) of Se(IV) and the relative standard deviation for 5 replicate determinations at 250 μg L(-1) concentration level was 2.45%. Recovery values were obtained between 97.8% and 102.8% for spiked samples. The method was successfully applied to the determination of total selenium in some food samples and alcoholic and nonalcoholic beverages. Its validity was checked by the analysis of four certified reference materials. The results obtained by the proposed method were quantitatively in good agreement with the certified values.