Fast on-line selenium determination in enriched yeast slurry by microwave digestion–hydride generation–atomic absorption spectroscopy

The analytical performance of an on-line focused microwave digestion method for the determination of selenium in enriched yeast by hydride generation–atomic absorption spectrometry (HG–AAS) is evaluated. The method is based on the direct injection of slurried samples into a carrier stream of water. Microwave-assisted digestion in the presence of 1% K₂S₂O₈ permits the quantitative extraction of selenium species from the solid samples and their transformation with HCl acid to selenite. Based on a sample injection volume of 100 μl, limits of detection (L.D.) of about 1 ng Se and relative standard deviation (R.S.D.) of 4.5% were obtained. The results of comparison with traditional digestion procedures are reported.