Applications of Microwave Discharges to Elemental Analysis

Abstract

Atomic spectrometry is one of the oldest methods of elemental analysis. Over the last several decades it has been used in analytical laboratories under various forms (emission, absorption, fluorescence) and with a large number of atom generating devices (flame, arc, spark, electrothermal atomizer, plasma).1 During the initial development period, atomic spectrometry was confined to atomic emission, until the work by Walsh in 1955 on atomic absorption spectrometry.2 During the subsequent twenty years, the latter was the most widely used form of atomic spectrometry. In the mid seventies, atomic emission spectrometry underwent a revival through the development of plasma sources as atomization and excitation devices. Finally, in the mid eighties, plasma based mass spectrometry became a more common form of elemental analysis. Presently, atomic emission, atomic absorption and atomic mass spectrometries are the most common tools used by the analytical chemist to perform elemental analysis. In the case of atomic emission and mass spectrometries, a large number of different plasmas have been used and new plasmas sources are constantly being designed and improved.