Atomic emission spectroscopy

Atomic emission spectroscopy (AES) is a method of chemical analysis that uses the intensity of light emitted from a flame, plasma, arc, or spark at a particular wavelength to determine the quantity of an element in a sample.

Robert Bunsen and Gustav Kirchhoff were the first to establish atomic emission spectroscopy as a tool in chemistry.

The width of spectral lines can provide information about an atom’s kinetic temperature and electron density.

The heat from the flame evaporates the solvent and breaks intramolecular bonds to create free atoms.

Each element emits light at a characteristic wavelength, which is dispersed by a grating or prism and detected in the spectrometer.

A frequent application of the emission measurement with the flame is the regulation of alkali metals for pharmaceutical analytics.

[5][6] Advantages of ICP-AES are the excellent limit of detection and linear dynamic range, multi-element capability, low chemical interference and a stable and reproducible signal.

Disadvantages are spectral interferences (many emission lines), cost and operating expense and the fact that samples typically must be in a liquid solution.

Spark or arc atomic emission spectroscopy is used for the analysis of metallic elements in solid samples.

In traditional arc spectroscopy methods, a sample of the solid was commonly ground up and destroyed during analysis.

An electric arc or spark is passed through the sample, heating it to a high temperature to excite the atoms within it.

The excited analyte atoms emit light at characteristic wavelengths that can be dispersed with a monochromator and detected.

Both qualitative and quantitative spark analysis are widely used for production quality control in foundry and metal casting facilities.