A kinetic theory of atomisation for non-flame atomic-absorption spectrometry with a graphite furnace. The kinetics and mechanism of atomisation for copper

Abstract

A kinetic approach has been made to the atomisation process in nonflame atomic-absorption spectrometry. Time-absorbance profiles for the determination of copper, using a graphite furnace, have been investigated in the temperature range 1720 to 2220 K and a rate equation derived that describes the variation of the amount of copper atoms in the furnace with time. It has been shown that a slow first-order reaction involving reduction of copper oxide by carbon followed by the rapid vaporisation of the copper formed is the most probable reaction mechanism. The greater sensitivity achieved in the determination of copper using a tantalum-lined graphite furnace has been attributed in part to the greater rate of reduction of copper oxide by tantalum.