Spectrographic Determination of Indium and Gallium in Cadmium Telluride Using Alumina-Cup Electrode

Abstract

A spectrographic technique using a specially designed cup electrode is proposed for the determination of indium and gallium in a solution of cadmium telluride. The electrode consists of an alumina cup which serves as a reservoir for the sample and a central tungsten rod supporting a graphite rod. It allows the excitation under low voltage over damped discharge. The method is especially useful for analysis of small quantities of material. The addition of a suitable amount of lithium has been found to enhance the intensity of the neutral atom lines of indium and gallium. Approximate determination limits for indium and gallium are 0.5 μg/ml, and the coefficient of variation for the determination is about 6% at the 5 μg/ml level.