The use of non-resonance lines for the determination of lead, indium and thallium by electrothermal atomic absorption spectrometry

Abstract

Non-resonance lines of Pb, In and Tl show a considerable analytical potential. Calibration curves constructed at some non-resonance wavelengths are more linear in absorbance than those at resonance lines. It is to be expected that using a monochromator of higher resolution one may further enhance sensitivity and calibration curve linearity of the 261-nm non-resonance line of Pb. While with platform vaporization, the non-resonance lines of the volatile elements show an appreciable sensitivity, with wall vaporization the sensitivity is rather poor. Even with platform vaporization, at temperatures over 2200°C, convectional losses hinder further enhancements of non-resonance line sensitivity. Using specially designed graphite furnaces and matrix modification, the sensitivity of non-resonance lines could be further enhanced. Since the non-resonance line peaks evolve slightly later in time than those of the resonance lines, vapor phase dissociation interferences are expected to be less important for the former.