An instrumental analysis technique that can quantitatively and qualitatively characterize materials based on their absorption and emission of radiant energy. When energy, such as UV light or infrared radiation, passes through a material, some, but not all, wavelengths may be absorbed. Measurement of the entire range of the transmitted radiation produces a spectrum that shows which wavelengths were selectively absorbed. This is called absorption spectroscopy and is usually done in the ultraviolet, visible, and infrared regions of the electromagnetic spectrum. Additionally, some materials may reemit the absorbed energy as a photon of the same or lesser energy. This is called emission, fluorescence or phosphorescence spectroscopy depending on the energy and length of time required for the emission.
Synonyms and Related Terms
"Absorptionsspektroskopie (Deut.); absorption spectrometry; spectrophotometry; absorptimetry