Evaluation of the Analytical Capabilities of a dc Plasma-Echelle Spectrometer System

Abstract

The analytical capabilities of a dc plasma used in combination with an echelle spectrometer have been evaluated. Measurements of the spectrometer resolution capabilities have demonstrated that they closely approximate the high values theoretically predicted but are ultimately limited by Doppler broadening effects occurring in the plasma. Investigations of possible ionization interference effects have shown that enhancements due to the addition of easily ionized elements are generally observed for elements having ionization potentials below approximately 8.5 eV; these may be compensated for by the addition of an excess of an easily ionized element. Evaluation of solute vaporization interference effects indicates that they also occur but can be negated by proper choice of operational conditions and/or the addition of releasing agents. Comparison of the detection capabilities of the system with those reported for other techniques shows that they are equivalent or superior to those characteristic of flame atomic absorption and often competitive with those obtained with the inductively coupled plasma, atomic emission system.