Atomic absorption spectrophotometry

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Atomic Absorption Spectrophotometry, also known as AA or AAS, is a method for determining the metals that are suspended or dissolved in a solution. This technique can be used for alkalis, alkaline earths, and transition metals. AAS is a very sensitive form of spectrophotometry, as it can detect elements with a concentration of less than one part per million in a small sample of the solution.

Atomic absorption spectrophotometry utilizes a device known as an atomic absorption spectrophotometer to determine the amount of a desired metal in a solution. An atomic absorption spectrophotometer works by turning a solution into an aerosol, and then atomizing it using an intense flame. Once atomized, a hollow cathode lamp, specific to the metal desired to be detected, emits a light through the sample. The atomic absorption spectrophotometer's photomultiplier tube is then able to detect the amount of light absorbed by the desired metal, which the machine outputs as a reading.

While spectrophotometry is more accurate, spectroscopy is more commonly used. See Atomic absorption spectroscopy