Application of a selenium hydride-atomic absorption technique to test for homogeneity of USGS standard rock

After acid decomposition of the sample, selenium hydride was generated by means of sodium borohydride, and the gas was swept through a resistance-heated quartz cell mounted in an atomic absorption spectrometer to determine as little as 5 ng/g selenium in 0.25 g rock sample. One-way analyses of variance of data from nine USGS standard rocks indicated no significant differences in selenium content among bottles of any of these rocks.