gDetermination of trace amounts of antimony in pure copper by high-power nitrogen microwave-induced plasma atomic emission spectrometry with hydride generation

Abstract

An annular-shaped high-power nitrogen microwave-induced plasma (N₂-MIP) produced at atmospheric pressure by an Okamoto cavity has been used as a new excitation source for the determination of trace amounts of Sb in pure copper by hydride generation atomic emission spectrometry (AES). Under the optimized experimental conditions, the best attainable detection limit at the Sb I 217.581 nm line by use of N₂-MIP-AES coupled with hydride generation was 4.46 ng ml^–1 of Sb with a linear dynamic range of 50–5000 ng ml^–1 of Sb. The presence of several diverse elements was found to cause a depressing interference on the determination of Sb using the present technique. Of several pre-reductants examined, thiourea was found to be the most preferable to reduce Sb^V to Sb^III prior to hydride generation for the determination of total Sb i.e., Sb^III+Sb^V. The present method using thiourea not only as a pre-reductant but also as an interference-releasing agent was applied to the determination of low concentrations of Sb in samples of high-purity copper metals. The results obtained by this method were in good agreement with the reference values.