Flame and Vapor Generation Atomic Absorption Spectrometry
Published Online: 15 SEP 2006
Copyright © 2000 John Wiley & Sons, Ltd. All rights reserved.
Encyclopedia of Analytical Chemistry
How to Cite
Amos, M. 2006. Flame and Vapor Generation Atomic Absorption Spectrometry. Encyclopedia of Analytical Chemistry. .
- Published Online: 15 SEP 2006
Atomic absorption spectrometry (AAS) is a means of specific analysis for most of the metallic and metalloid elements. It achieves its specificity from the highly selective absorption, by free atoms of the analyte, of atomic emission of the same element at characteristic wavelengths. In its simplest form of application the free atoms of the analyte are created by aspiration of a solution of the sample to be analysed into a suitable flame, flame atomic absorption spectrometry (FAAS). The other principal means employed for the production of atoms (atomization) are graphite furnace atomization (GFAAS) and vapor generation atomization (VGAAS). Sample volumes of a few milliliters are normally needed for FAAS and VGAAS, but smaller volumes are needed for GFAAS. For most of the approximately 65 elements amenable to measurement by AAS, detection limits are from parts per billion to parts per million by flame methods and from parts per trillion to parts per billion levels by GFAAS and VGAAS. FAAS is inherently simple and rapid to use, whereas GFAAS and VGAAS are less rapid. The instrumentation used for AAS is relatively inexpensive Since all of these methods generally require the sample to be in solution form, the need for dissolution may be seen as a limitation in some cases. In the most common instrumentation employed, elements are only measured one at a time. It follows that for the determination of many elements in a large group ofsamples the method must be seen to be slow by comparison with multielement techniques such as inductively coupled plasma mass spectrometry (ICPMS) and inductively coupled plasma atomic emission spectrometry (ICPAES). However, the equipment costs involved for these techniques are generally higher and they are more complex to employ.