Determination of traces of tellurium in heat-resisting alloys by graphite-furnace atomic-absorption spectrometry after co-precipitation with arsenic.

A simple analytical method has been developed for the determination of traces of Te in complex heat-resisting alloys by graphite-furnace atomic-absorption spectrometry. Nickel-base and cobalt-base heat-resisting alloys are dissolved in concentrated hydrochloric and hydrofluoric acids plus 30% hydrogen peroxide. Tellurium is separated from the matrix by co-precipitation with As and dissolved in nitric acid. Memory effects are eliminated by the oxidation of Te(IV) to Te(VI). Standard solutions for the calibration are prepared by the procedure used for the sample solution. The detection limit for Te is 0.05 ppm in the alloy.