ABSTRACT
This chapter is concerned with atomic absorption spectrometry (AAS), which is a very widely used technique for the determination of over 20 elements in soils, plants, waters, and other environmental materials. It also briefly covers flame emission spectrometry (FES), which is also widely used, but for the determination of a smaller number of elements. For some elements at very high concentrations, absorption of visible light by atoms can be readily observed. Our sun’s spectrum, for example, shows several dark absorption lines where the continuum emitted from the high-temperature solar surface is selectively absorbed by free atoms of elements such as sodium in the solar atmosphere. These dark lines, the Fraunhofer lines, are perhaps the oldest and best-known example of atomic absorption.
