Atomic absorption spectroscopy (AAS) is a spectroanalytical procedure for the quantitative determination of chemical elements using the absorption of optical radiation (light) by free atoms in the gaseous state. In analytical chemistry the technique is used for determining the concentration of a particular element (the analyse) in a sample to be analysed. AAS can be used to determine over 70 different elements in solution, or directly in solid samples via electrothermal vaporisation, and is used in pharmacology, biophysics and toxicology research.
