Determination of ultratrace amounts of gold in geological materials by arc emission spectrometry using gas chamber profile electrodes

Abstract

A new method is described for the determination of ultratrace amounts of gold in geological samples. The method is based on arc emission spectrometry using gas chamber profile electrodes that have been developed in our laboratory. A liquid reagent (NH₄l) was successfully used as a spectrochemical carrier. The technique involves separation of gold by sorption on a foamed plastic column. The detection limit of the method is 0.2 ng g^–1 and the limit of quantification is 0.5 ng g^–1. The concentration of gold in the analysed samples ranged from 0.5 to 50 ng g^–1. Studies on the analytical precision showed that the relative standard deviation of this method is 5%(3–50 ng g^–1) and 20%(0.5–3 ng g^–1). Results obtained for gold in two Chinese geological standard samples were in good agreement with the certified values. The technique is characterized by its simplicity, rapidity, high sensitivity and improved analytical precision and accuracy.