Construction And Basic Study On Application Of Microwave Plasma Torch Ionization Source

Mass spectrometry as an important analytical technique, is widely used in the fields of chemistry, physics, biology, medicine and so on. Ionization source is the core of the mass spectrometer, and ambient ionization technique is a trend of development of the ionization techniques for mass spectrometry. The dissertation set up a novel ambient ionization source which was based on the technologies of microwave plasma torch. In the process of development, we design the all solid-state microwave source which has advantages of good reliability, high stability, low voltage and easy maintenance. In addition, begin the study of Modbus protocol, we develop a control system, introduce the configuration of hardware and software program of PC. The application shows that this system runs stably and easy to be operated, it effectively improves the overall performance of the ionization source. Finally, we test and optimize the parameters and used it to analyze the gunshot residue. The result prove that it has as many advantages:no need for sample pre-treatment, fast detection, high sensitivity.The main studies done in this dissertation are as follows:1. Discuss the development of mass spectrometry technology. Briefly introduce the plasma technology and ionization technology.2. Ionization source for mass spectrometry are reviewed from the traditional and ambient areas. The principle, construction, applications, advantage and disadvantage of these techniques are summarized systemically.3. A novel ionization source is developed for microwave plasma torch ionization. The principle and structure are described. The key point is to design the all solid-state microwave source and control system4. Basic study on application of microwave plasma torch of ionization source. Optimized some parameters and analyzed the background of atmospheric, designed a rapid method for detection of the gunshot residue.5. Summary and perspective.