What is the principle of chemiluminescence
Chemiluminescence is a common natural phenomenon which is different from Photoluminescent film. The use of chemiluminescence reaction reactants, catalysts, sensitizers, inhibitors, coupling reaction reactants, catalysts, sensitizers method is called chemiluminescence method. So how does chemiluminescence work? Below small make up to introduce the principle of chemiluminescence.
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 certain step alone; because the energy released by the reaction in the previous step will disappear into the solution due to the vibrational relaxation and cannot emit light.
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 generate an excited state.
Third, the excited state molecule must have a certain chemiluminescence quantum efficiency to release the photon, or be able to transfer its energy to another molecule to enter the excited state and release the 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 factors affecting the reaction speed can be used as the basis for establishing the determination method.
Chemiluminescence reaction can be generally expressed as:
A plus B times C times 1.
C ` - C + hv (2)
Chemiluminescence intensity (Ic) depends on reaction speed (dP/dt) and chemiluminescence quantum efficiency (95CL).
IcL (t) = q5cLdP/dt (3), where 'PCL = 0, where, is the quantum efficiency Of molecules generated in the excited state, and Of is the luminescence quantum efficiency Of molecules generated in the excited state.
For a certain chemiluminescence reaction, 45CL is a certain value, and the reaction rate can be expressed in accordance with the law of mass action and the relationship between the concentration of substances in the reaction system. Therefore, the concentration of a Photoluminescent film in the reaction system can be determined by measuring the chemiluminescence intensity. In principle, for any chemiluminescence reaction, as long as the reaction is a first order or a pseudo first order reaction, the chemiluminescence quantitative analysis can be carried out by formula (3). For example, in the above chemiluminescence reactions, if substance B remains constant and the concentration of substance A changes and can be considered as A first or pseudo-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 kind of substances are catalysts, sensitizers or inhibitors in chemiluminescence reactions. The third kind of materials are reactants, catalysts and sensitizers in coupling reactions. These three kinds of substances can also be used to determine other substances of interest by means of labeling, which further expands the application scope of chemiluminescence analysis.
