Concomitant Effects in a Magnetron Rotating Direct-Current Arc Plasma with Graphite-Furnace Sample Introduction

Abstract

The effects of the concomitant species Li, K, and Zn on analyte emission line intensities from a magnetron rotating direct-current arc plasma are described. The arc plasma has the form of a radial current sheet which completely covers the end of the graphite anode. The sample vapor from a graphite furnace is forced to pass through the current sheet. The presence of an easily ionized element (EIE) does not significantly alter the sample/plasma interaction. Large increases in emission intensities from both neutral-atom and ion lines of the analyte are observed in the presence of K or Li. This is probably the result of increased electron density in the plasma tail flame. Concomitant species which are not easily ionized have a smaller effect on analyte emission intensities, and either intensity enhancement or suppression effects are observed. Significantly lower detection limits are obtained in the presence of an EIE.