Electrothermal Atomic Absorption Interference Studies Using a Wire Loop Atomizer

Abstract

A W-Re wire-loop atomizer has been used to study interference effects caused by diverse compounds in the ETAAS determination of Cu, Cd, Mg, and Be. Absorbance-time profiles of both the analyte and the diverse metal were studied. In most cases, overlap of the AA signal of the diverse metal with that of the analyte depressed the analyte's signal. The major mode of suppression appears to be the formation of analyte compounds, such as oxides or chlorides, in the vapor phase. Shifts in appearance temperature were also observed, especially in the case of Cd, which was the most volatile metal studied. The addition of sulfate increased the appearance temperature of Cu and decreased or eliminated the suppression caused by Na and K salts.