Application of Zeeman background correction to direct current plasma excited atomic absorption spectroscopy

Abstract

The Zeeman effect is employed for background correction in a plasma assisted atomic absorption spectrometer, which has been developed for on-line analysis of hazardous metals in gas flows. In this paper we study the efficiency of Zeeman background correction and the influence of the magnetic field on the properties of the plasma. The experiments showed that the efficiency of Zeeman background correction is comparable to the values reported for flame and graphite furnace atomizers. The magnetic field was found to interact strongly with the plasma, thereby deteriorating the plasma stability and lowering the kinetic temperature of the plasma jet. These had an adverse effect on the signal-to-noise ratio and atomization efficiency, respectively. Therefore we introduced a magnetically shielded plasma atomizer, in which the interaction between the magnetic field and the plasma was effectively hindered.