Application of the slurry technique to the determination of selenium in fish samples by electrothermal atomic absorption spectrometry

The proposed method permits rapid analysis of selenium in fish samples by avoiding sample pre-treatment. Factors affecting the stability of the slurry (particle size and stabilizer), furnace heating conditions and various chemical modifiers and selectivity agents, were investigated. Palladium was selected as the chemical modifier, together with 1.0 per cent m/v ammonium oxalate to improve selectivity. The calibration graph was linear from 2.5-25 ug selenium per litre with a detection limit of 0.33 ug selenium per litre. RSD for multiple within-run and between-day analyses of a fish homogenate sample were 5.9 and 9.2 per cent, respectively. The accuracy of the method was confirmed by comparison of the results with those obtained with a microwave digestion method in the analysis of 5 lyophilized fresh fish samples and a fish homogenate standard reference material (SRM MA-A-2 No.1062/TM) with a certified concentration of 1.7 ug selenium per g. The results for 5 analyses of the reference material were 1.63 ug selenium per g using the slurry technique and 1.69 ug selenium per g using the microwave digestion procedure. There are 31 references.