Chemiluminescence is a common natural phenomenon, the use of chemiluminescence determination of chemiluminescence reaction reactants, catalysts, sensitizers, inhibitors, coupling reaction reactants, catalysts, sensitizers method is called chemiluminescence method. So, what is the principle of chemiluminescence? Below small make up to introduce the principle of chemiluminescence.
In order for a chemical reaction to produce chemiluminescence, the following conditions must be met: first, the reaction must provide sufficient excitation energy, which is provided by a single step, since the energy released in the previous step will be lost in the solution due to vibrational relaxation. The second is to have a favorable reaction process, so that the energy of the chemical reaction can be accepted by at least one substance and form an excited state; And the third is that the excited molecule has to have some sort of chemiluminescence quantum efficiency to release a photon, or to be able to transfer its energy to another molecule to get into the excited state and release a photon.
Chemiluminescence reaction can be used for analysis and determination, because the intensity of chemiluminescence is related to the speed of chemical reaction, so all the factors affecting the reaction speed can be used as the basis for establishing the determination method.
Chemiluminescence reactions can generally be expressed as:
A plus B minus C times 1.
C ‘–C+hv (2)
The strength of chemiluminescence (Ic) depends on the speed of the reaction (dP/dt) and the quantum efficiency of chemiluminescence (95CL).
In IcL (t) = q5cLdP/dt (3), ‘PCL = 0, wherein, is the quantum efficiency Of generating excited state product molecules, and Of is the luminous quantum efficiency Of excited state product molecules.
For a certain chemiluminescence reaction, 45CL is a certain value, and the reaction speed can be expressed in relation to the concentration of substances in the reaction system according to the law of mass action. Therefore, the concentration of a certain substance in the reaction system can be determined by measuring the intensity of chemiluminescence. In principle, for any chemiluminescence reaction, as long as the reaction is a first or false first step reaction, the chemiluminescence can be quantitatively analyzed by formula (3). For example, in the above chemiluminescence reaction, if substance B remains constant and the concentration of substance A changes and can be regarded as A first or false first order reaction, then:
ICL = fICL (t) dt = f95CL [dCA/dt] dt = 95CLCA (4), that is, the intensity of chemiluminescence is proportional to the concentration of A.
The substances determined by chemiluminescence analysis can be divided into three categories. The second class of substances are catalysts sensitizers or inhibitors in chemiluminescence reactions; The third kind of material is the reactant, catalyst and sensitizer in the coupling reaction. These three types of substances can also be labeled to determine other substances of interest, further expanding the application of chemiluminescence analysis