Atomic emission spectrometry (AES) uses a quantitative measurement of the optical emission from stimulated atoms to determine the concentration of the substance to be analysed.
The atoms or molecules that are stimulated to high energy levels can disintegrate at lower levels emitting radiation (emission or luminescence). For atoms stimulated by a high temperature energy source, this emission of light is commonly called atomic or optical emission (atomic emission spectroscopy), and for atoms stimulated by light, the term atomic fluorescence is used (atomic fluorescence spectroscopy).
The atoms of the substance to be analysed in the solution are sucked into the stimulation region where they are dissolved, vaporised and atomised by a flame, a discharge or a plasma. These sources of high temperature atomisation provide enough energy to propel the atoms to high energy levels. The atoms disintegrate, returning to lower levels while emitting light.
AES using a flame, also called flame emission spectroscopy (FES), is widely used in elementary analysis. It can be used both for quantitative and qualitative analysis, and is a simple element method. Its most important applications are in the determination of sodium, potassium, lithium and calcium in biological tissue.