Application of Luminescence Spectrometry to the Analysis of Fuels

Abstract

Luminescence spectrometry, which includes fluorescence and phosphorescence, is based on the absorption and reemission of light by a molecule, ion, or atom. It is of great analytical usefulness because the emitted light is characteristic of the electronic structure of the emitting substance. The phenomenon of luminescence is not new; the first monograph on luminescence was written by Liceti in 1640.⁽¹⁾ In 1845, Herschel⁽²⁾ reported on the luminescent characteristics of quinine sulfate. Stokes,⁽³⁾ in 1852, observed that, in all cases, the light emitted from a molecule was at longer wavelengths than that which it absorbed. His observation was termed the “Stokes shift” and has since become well understood. In 1895, Weidman and Schmidt,⁽⁴⁾ and, in 1907, Stark and Mayer,⁽⁵⁾ reported the first systematic study of luminescence of aromatic molecules.