Validation of method for total selenium determination in yeast by flame atomic absorption spectrometry

A procedure using open digestion followed by flame atomic absorption spectrometry is described for measuring the total selenium content of Se-enriched yeast. The limits of detection and quantitation were 2.5 mg/L and 5 mg/L Se, respectively. The signal response was linear over the range of 5-50 mg/L Se, and the average recovery from spiked samples was 98.9%. The validated method was used to measure the Se content of Se-enriched yeast reference material and produced a result of 2145 +/- 38 mg/kg (n = 3), which is in good agreement with the certified level of 2125 +/- 65 mg/kg.