Determination of trace amounts of selenium and tellurium in nickel-based heat-resisting superalloys, steels and several metals by electrothermal atomic absorption spectrometry after reductive coprecipitation with palladium using ascorbic acid

Trace amounts of selenium and tellurium in nickel-based heat-resisting superalloys and constituent metals were separated by a reductive coprecipitation technique with palladium using ascorbic acid, and determined by electrothermal atomic absorption spectrometry. Selenium and tellurium each added in 1 μg amounts to solutions of metals (Ni, Al, Cr, Co, Cu, Mn, Mo, V, Ti, Nb, Ta, W and Zr), were recovered by the proposed method. In all metals, both selenium and tellurium were quantitatively recovered in H₂SO₄, H₂SO₄-tartaric acid, H₂SO₄-oxalic acid or H₂SO₄-H₃PO₄ solution. In Ni, Al, Nb, Ta, W and Zr, they were also quantitatively recovered in HF-H₂SO₄ solution. This proposed method could be adapted to determine trace amounts of selenium and tellurium in several alloys (heat-resisting superalloys, stainless steels and high speed steels).