Application of a simplified model for atom formation by a tungsten-strip heater in atomic absorption spectrometry

Abstract

A model has been proposed for the mechanism involved in atom formation in electrothermal atomisation atomic absorption spectrometry. To simplify the investigation, a tungsten-strip heater was used as the atomiser. The model is based on the assumption that the rate of atom formation, given by a simple Arrhenius type expression, is a function of the number of atoms of the sample on the heater and the heater temperature. Signal measurements were made using a fast-response electronic system developed to remove signal distortion. Experimental results obtained for Ag, Cu and Fe demonstrated the validity of the proposed model. Activation energies of the model are also given for these analytes.