APPLICATION OF THE SLURRY TECHNIQUE TO THE DETERMINATION OF SELENIUM IN FISH SAMPLES BY ELECTROTHERMAL ATOMIC-ABSORPTION SPECTROMETRY

A slurry technique was applied in the development of a sensitive and p recise method for selenium determination in fish samples without sampl e pre-treatment, Several pyrolysis curves were investigated and differ ent chemical modifiers were tested. Ammonium oxalate was used to impro ve the selectivity. Calibration within the range 2.5-25.0 mu g l(-1) S e was performed with aqueous standards. The detection limit was calcul ated as 0.33 mu g l(-1) and the RSD of the measurements was 5.9% for r epeatability and 9.2% for reproducibility. The reliability of the enti re procedure was confirmed by analysis of a standard reference materia l and by comparison with a microwave digestion procedure.