Sample introduction system for direct current plasma atomic emission spectrometry

Abstract

A dual pump-nebulisation sample introduction system for direct current plasma atomic emission spectrometry (DCP-AES) was designed both to enhance sensitivity and to reduce interferences. A solution of the sample and a solution of easily ionised element (EIE) of constant concentration were introduced separately into the DCP through two pump-nebulisation assemblies and a modified sample introduction tube. Hence the buffering effect of the EIEs was easily achieved without adding EIEs to the sample solution during sample preparation. This system was evaluated by its application to the determination of V, Cr, Mn, Fe and Ni. Ionisation interferences from the sample matrix were reduced to negligible levels. Detection limits for the elements determined were better than those obtained using a commercial DCP-AES system without modification.