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 precise method for selenium determination in fish samples without sample pre-treatment, Several pyrolysis curves were investigated and different chemical modifiers were tested. Ammonium oxalate was used to improve the selectivity. Calibration within the range 2.5-25.0 mu g l(-1) Se was performed with aqueous standards. The detection limit was calculated as 0.33 mu g l(-1) and the RSD of the measurements was 5.9% for repeatability and 9.2% for reproducibility. The reliability of the entire procedure was confirmed by analysis of a standard reference material and by comparison with a microwave digestion procedure.