Atomic Absorption/Atomic Emission
In Atomic Absorption Spectroscopy, or AA, a liquid sample is aspirated and atomized into a high-temperature flame. Light of a specific wavelength characteristic to the metal of interest, provided by a hollow cathode lamp, is passed through the flame containing the atomized sample. The corresponding metal atoms in the flame absorb the light, resulting in a quantitative reduction of the light reaching the detector. This measured absorption can then be used to accurately determine the specific metal content of the sample solution.
Atomic Emission Spectroscopy, or AE, is similar to Atomic Absorption Spectroscopy as described above. However, no external light source is used. In Atomic Emission Spectroscopy, electrons of the atoms of interest are promoted to excited states in the flame and emit their characteristic radiation as they return to the ground state. The emission intensity at the characteristic wavelength is proportional to the concentration of the element in the sample.
Atomic Absorption and Atomic Emission may be used for quantitative and qualitative single-element determinations.