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Technique:
Atomic Absorption Spectroscopy is a technique for quantifying the concentration of elements, metals and a few metalloids, dissolved or suspended in a solution utilizing absorption, emission or fluorescence properties of light by atoms from a vaporized sample. In AAS, a cathode discharge lamp produces specific wavelengths of light that are characteristic of the element under study. The energy from the lamp will be absorbed at the atomic level, only by this specific element. This means that this technique works well, even with contamination from other elements.
Application:
Flame AA is very sensitive for individual elements. With a graphite furnace (GFAAS) attachment, the sensitivity increases dramatically for some elements.
The Science Behind:
AAS works by starting with a small sample, digesting the sample to produce a uniform liquid solution, usually in a concentrated acid. The solution is introduced into the flame by atomizing it in a spray chamber. The very fine mist is introduced into a very hot flame, usually acetylene /air mix, to produce individual atoms. A beam of light is generated by the emitter, at specific wavelengths of light for the element under study. The atoms, from the sample, absorb the wavelength specific to that element as the beam of light is passed though the flame. The amount of change in the intensity at specific wavelengths is directly proportional to the quantity of the element in the solution.
Other References:
Wikipedia Definition of Atomic Absorption Spectroscopy
Simple AA e-Textbook
Excellent Spectral Chart
Emitter - The emitter is a hollow cathode lamp selected for individual metal being tested.
Spectroscopy - The study of parts of the electromagnetic spectrum interacting with matter.
Spectrophotometry - The study of parts of the electromagnetic spectrum that deals with visible light, near-ultraviolet and near-infrared. While Spectrophoto- metry is a more accurate term, Spectroscopy is the more commonly used term.
Spray Chamber - A device that takes a small stream of a liquid and turns it into a mist where most of the original liquid is discarded.
Spectroscopy - The study of parts of the electromagnetic spectrum interacting with matter.
Spectrophotometry - The study of parts of the electromagnetic spectrum that deals with visible light, near-ultraviolet and near-infrared. While Spectrophoto- metry is a more accurate term, Spectroscopy is the more commonly used term.
Spray Chamber - A device that takes a small stream of a liquid and turns it into a mist where most of the original liquid is discarded.