DETERMINATION OF TRACE AMOUNTS OF SELENIUM AND TELLURIUM IN HIGH-PURITY IRON BY ELECTROTHERMAL ATOMIC-ABSORPTION SPECTROMETRY AFTER REDUCTIVE COPRECIPITATION WITH PALLADIUM USING ASCORBIC-ACID

Trace amounts of selenium and tellurium in high-purity iron were quantitatively separated by a reductive coprecipitation technique with palladium, and determined by electrothermal atomic absorption spectrometry. When ascorbic acid was used as reductant, selenium and tellurium could be simultaneously separated from large quantities of iron. The precipitate was dissolved in HNO3 and HCl, then the sample solution was injected into a graphite furnace with ascorbic acid solution. The atomic absorbance of selenium was increased about 4 times, and the atomic absorbance of tellurium was increased about 3.5 times by the presence of palladium. The detection limits (3 sigma) of selenium and tellurium were 0.01(7) mu g g(-1) and 0.01(1) mu g g(-1), respectively.