Effect of Easily Ionized Elements upon the Spatial Emission Properties of Microwave-Induced Plasmas

Abstract

Spatially resolved measurements of emission from microwave-induced plasmas (MIPs) sustained in helium in a Beenakker resonant cavity and in a surfatron have been compared and contrasted. Particular emphasis has been placed upon the study of a common interference effect in MIP sources, namely the enhancement (or suppression in some instances) of analyte emission intensity by matrices containing an easily ionized element (EIE). The presence of the EIE caused a strong enhancement of analyte emission in the Beenakker cavity system but had a relatively smaller influence upon analyte emission in the surfatron system at higher concentrations of EIE. The difference in behavior between the two systems toward EIEs appears to be attributable to improved sample injection into the plasma in the case of the surfatron.