Determination of lead in steel by high power nitrogen microwave induced plasma atomic emission spectrometry coupled with hydride generation technique

Abstract

An annular-shaped high power nitrogen microwave induced plasma atomic emission spectrometry with a hydride generation method is described for the determination of lead in steel. Under the optimized experimental conditions, the best attainable detection limit at the Pb I 368.347 nm lines was 35.2 ng ml⁻¹ for lead. The linear dynamic range for lead was 100 to 30000 ng ml⁻¹ in concentrations. The presence of several diverse elements was found to cause a more or less depressing interference with the proposed technique. Of the several oxidizing agents examined, hydrogen peroxide for lead was found to be the most preferable to oxidize lead prior to hydride generation. When lead in two certified reference materials of steel was determined, a large amount of Fe(III) in the solution caused a severe depressing interference, while the presence of Fe(II) showed little or no significant interference. Of the several interference-releasing agents examined, L-ascorbic acid was found to be the most preferable to pre-reduce Fe(III) to Fe(II). The concentrations of lead in steel were determined by the use of the standard additions method. The results obtained by this method were in good agreement with their certified values.