Development Of A New Ambient Ionization Source Based On Electrothermal Vaporization And Pulsed Corona Discharge

With the improvement of the people living standards, and the acceleration of industrialization and urbanization, Human activities had done harm to the environment, such as the heavy metal contamination and the air pollution which were hazards to human health and life. Because of the heavy metal contamination and the air pollution, conventional detection methods at this stage can not meet the trace heavy metal contamination and air pollution monitoring requirements. So from the above problems, the essay had done in-depth study about the heavy metal contamination and air pollution monitoring techniques. Then we developed a new ambient ionization source which was based on the technologies of electrothermal vaporization and pulsed corona discharge. It had a good result on the heavy metal contamination and air pollution detection. Main tasks were as follows:1. The mass spectrometry technology and the developing trend were introduced briefly. Then we discussed the traditional mass spectrometry ionization source, systematic summarized the current research and development about the ambient ionization source.2. The overall structure of the new ambient ionization source and the composition of the various parts were briefly introduced, analyzed the functions of the various parts. We introduced the automatic sampling system, the structure of the hardware and software.3. The current research and the detection methods about the heavy metal pollutants detection were showed. Then we explained how to detect the heavy metal pollutants using the electrothermal vaporization-assisted pulsed corona discharge ionization source under ambient conditions. With the experimental conditions optimized, we analyzed the mass spectra, got the limit of detection and the good results. Then we had a discussion about the phenomenon and results.4. The current research and the detection methods about the air pollutants detection were showed. Then we explained how to detect the air pollutants using the electrothermal vaporization-assisted pulsed corona discharge ionization source under ambient conditions. With the experimental conditions optimized, we analyzed the mass spectra, got the good results. Then we had a discussion about the phenomenon and results.Using the new ambient ionization source, we had good results on detecting the vanadium, chromium, manganese, arsenic, the limit of detection could get to 6.5×10-13 g,1.4×10-12 g,1.7×10-12 g,2.1×10-12 g, better than the conventional detection techniques. We could detect the toluene in the nitrogen, the limit of detection can be 0.13 mg/m3, better than the conventional gas chromatography techniques. The new ionization source had a simple structure, convenient operation, low energy consumption, and easy to use online.