ABSTRACT
Spectroscopy of molecular fluorescence, phosphorescence and phenomena of chemiluminescence is based on the phenomenon of luminescence. The origin of the phenomenon of fluorescence and phosphorescence is explained by the diagram of Jablonsky. It is established that the intensity of the radiation of fluorescence is directly proportional to the concentration of the fluorescent sample in the cell of measurement. Fluorescence spectroscopy is a quantitative very sensitive method. Concentrations as weak as 10-8, 10-9 mol L-1 can be determined but the intensity of fluorescence may be very easily modified by the presence of impurities. Fluorescence spectroscopy, overall, has numerous quantitative applications among organic molecules, notably in the pharmaceutical field and in biochemical analysis but not all organic molecules are likely to fluoresce. Phosphorimetry has received few applications because very few molecules can give a phenomenon of phosphorescence. As for the phenomenon of chemiluminescence, it has equally received relatively few applications. Let us only cite the phenomenon of bioluminescence.
