Kinetic studies on the mechanism of atomization in electrothermal atomic absorption spectrometry with and without chemical modifiers.

Abstract

Over the past decade a few methods for determining kinetic data for atom formation from the absorption signal in electrothermal atomic absorption spectrometry (ETAAS) have been developed in the author's laboratory. These approaches include improvement to the Smets method, and development of new methods for simultaneous determination of kinetic order and activation energy for atom formation at increasing or constant temperatures. The steady-state approximation and first-order kinetic assumption for atom formation have been avoided during their derivation. One of the most distinct features of these new methods is their suitability for quantitative determination of the kinetic order for atom formation from absorption signals under normal analytical conditions, even for atomization processes with fractional reaction orders and/or with multiple mechanisms. The application of the developed methods to the study of the mechanism of atomization in the graphite-furnace atomizer, with and without chemical modifiers, is reviewed with emphasis on research work in the authors' laboratory.