Direct determination of selenium in human urine by electrothermal atomic absorption spectrometry with deuterium background correction

Abstract

The elaboration of methodology for the direct determination of Se in urine by ET-AAS has been contributed by several authors with the predominant use of Zeeman-background correction (BC) systems which is less affected by spectral effects. A systematic study of several recommended, less commonly applied, and new chemical modifiers, resulted in the optimization of atomization conditions under which accurate analysis became possible also with the use of deuterium lamp BC. Pd (nitrate) + Sr (iodide) + Ag (nitrate) was found to be preferable for the determination of Se in urine. The use of this modifier resulted in the lowest detection limit (3.6 μg L−1) and characteristic mass value (17 pg) and ensured the analytical recoveries close to 100 %. Applying the modifier to standards and samples has enabled the use of matrix-free standard solutions for attaining accurate analysis of diluted urine samples. The accuracy was verified by the use of quality control reference materials and by comparison with RNAA method.