Study On Determination Of Reactive Oxygen Species (ROS) By Sequential Injection Analysis Coupled With Chemilummescence Detection

Numerous free radicals are generated in the course of biology metabolism. Superoxide anion radical (O2-) and hydroxyl radical (OH) are the typical ones. Free radicals are continuously formed via environmental influence and aerobic metabolism. In healthy subject, there is a balance between the generation of ROS and the capacity of the antioxidant protective system, whereas, excessive ROS will induce aging and many diseases. It is necessary to study on the antioxidants which have scavenging free radical activity that has attracted many scientists’attention.The types, sources of free radicals and free radicals’promotion and damage influence on people had been reviewed, besides the definitions and a variety of measurement methods of superoxide anion radical and hydroxyl radical, this paper also summarized the research of antioxidant capacity of seven general Chinese Medicines.In the second part section of the thesis, a procedure for the determination of hydroxyl radical (OH) by sequential injection analysis coupled with chemiluminescence was described, which was based on the greatly increasing of chemiluminescence intensity of luminol-H2O2in a alkalic medium containing Co(Ⅱ)/EDTA as sensitizer. This method had been used to determine the scavenging activity of several hydroxyl radical scavengers. It was found that all samples within a certain range of concentrations had the inhibition activity to hydroxyl radical (OH). The method was successfully applied to compare the scavenging hydroxyl radical activity among seven Chinese Medicines. It was also found that Schisandra, Fleece-flower root and Gynostemma had stronger scavenging hydroxyl radical activity.In the third section, a new SI-CL method was developed for the determination of superoxide anion radical (O2-). Under the optimized condition, the detection limit (3a) was5.1×10-10mol/L. This method had been used to determine scavenging superoxide anion radical activity of several superoxide anion radical scavengers and seven Chinese Medicines. It was found that Licorice and Angelica had stronger scavenging superoxide anion radical activity (O2-).In the last section, a summary for the content of the experimentation was described.