Study On Chemiluminescent Mechanism Of Reactive Oxygen Species And Its Application In Analysis Chemistry

Along with the continuous development of the science and the interaction research of the life, environment and both relation, reactive oxygen species (ROS) and its related compounds play an important role in the life and environment. Nowadays, the research of ROS on life science, food chemistry, medicine and environment learned a great interest, and it has already developed to become a specialized research topic gradually.Chemiluminescence (CL) is a powerful analytical technique that has excellent sensitivity, wide linear dynamic range and requires relatively simple and inexpensive instrumentation. Furthermore, the CL is an effective method in the research of ROS, because of association instantaneousness of the CL with short life-time of ROS radicals. In the present work, the chemiluminescence detection of ROS and its analytical application were investigated. The research has important method instruction and theories for the study on the sorts and the generation mechanism of ROS. The contents were summarized as follows:1. In the review, the concept, character and CL detection of some important Reactive Oxygen Species (such as ¹O₂,^·O₂ ^-H₂O₂, ^·OH, HOOX (X = SO₃^-, NO, CO₂^-) ) are summarized. The recent development CL detection methods of the Reactive Oxygen Species are stressed. 2. Very strongly CL signal was observed when adding an aqueous solution of luminol or 2-methyl-6-(4-methoxyphenyl)-3, 7 -dihydroimidazo[1,2-a]-pyrazin-3-one hydrochloride (MCLA) to the suspension of CaO₂ respectively. The ROS released on CaO₂ were thought to be oxidizing agents leading to CL, and were characterized by CL, UV-visible (UV-vis) spectra and the effective scavengers of the special ROS. From experimental results, the hydroxyl (OH) and superoxide (^·O₂^-) radicals were suggested to exist on the surface of CaO₂. A reaction scheme for the formation of the ROS on CaO₂ was also proposed and discussed. Moreover, of more interest was the finding that the CaO₂, which released the ^·OH and ^·O₂^- on the surface, exhibited good transition property compared with the same group alkaline-earth metal peroxides (MgO₂, BaO₂).3. Rifampicin can enhance the chemiluminescence (CL) of peroxomonosulfate-cobalt(â…¡) system, and the relative CL intensity is strongly dependent on the rifampicin concentrations. Based on this phenomenon, a rapid and sensitive flow injection CL method was developed for the determination of rifampicin. The relative CL intensity was linear with the rifampicin concentration over the range of 5×10^-8 to 1×10^-6g mL^-1(r=0.9991), the detection limit was 7×10^-9 g mL^-1 (S/N=3), and the relative standarddeviation was 2.7% for 6×10^-7 g mL^-1 rifampicin (n=15). Furthermore, this method was successfully applied to the determination of rifampicin in real eye drop and capsules sample.4. The organic peroxides, such asmetachloroperbenzoic acid (MCPBA) and the tert-butyl hydroperoxide, were chosen to determinate the humic acid as chemiluminescent oxidants. Compared with the chemiluminescence of Na₂CO₃H₂O₂ and the Ce(â…£)-H₂SO₄ system, the MCPBA system own the gentle condition and strong static chemiluminescence for detecting the humic acid. The influence of surfactants to this chemiluminescent system was also investigated. Other surfactants did not paly role in increasing the chemiluminescence except sodium dodecyl benzene sulfonate(SDBS). The primal investigated about the MCPBA chemiluminescent system provided method guidance for the widening and choice of chemiluminescent oxidants.