chemiluminescent methods of detection

in analysis
https://doi.org/10.1351/goldbook.C01047
Methods which utilize gas or liquid phase reactions between two molecules which produce a third molecule in an excited state. The wavelength distribution of the light emission from the excited molecule is characteristic of the species; in some circumstances this may be used to identify and to determine the concentration of one of the reacting species.
Source:
PAC, 1990, 62, 17. 'Free energies of cation-molecule complex formation and cation-solvent transfers' on page 21 (https://doi.org/10.1351/pac199062010017)