In this work, a sensitive and robust vacuum ultra-violet (VUV) single-photon ionization (SPI) ion trap time-of-flight mass spectrometer (VUV-SPI-IT-TOFMS) for on-line, realtime monitoring of chlorinated organic compounds in waste incineration flue gas has been newly developed. The fragment-free SPI technique with 121.6-nm VUV lamp irradiated by a microwave generator and the quadrupole ion trap to accumulate and select analyte ions were combined with a reflectron time-of-flight mass spectrometer to detect chlorinated organic compounds at trace level. This measuring system was tuned up to detect dioxins precursors with the aim at an application to monitoring trace level toxic substances in flue gases from incinerator furnaces. As a result, this technology has made it possible to analyze trichlorobenzene (T3CB), a dioxin precursor, in 18 s with a sensitivity of 80 ng/m3-N (10 pptv) using the selective accumulation of analyte substances and separation of interfering substances in the ion trap. Moreover, the first field test of the continuous monitoring T3CB in an actual waste incineration flue gas had been done for 7 months. The results show that this system has an exceeding robust performance and is able to maintain the high sensitivity in analyzing T3CB for long months of operation.
A new synthesis method of fullerenes has been investigated for microwave induced naphthalene-nitrogen plasma at atmospheric pressure using a cylindrical coaxial cavity. The toluene extract solution of soot obtained after discharges showed HPLC peaks with retention times corresponding well to those of C60 and C70. The production of fullerenes was also confirmed by mass-spectrometric analysis. Gas temperature of nitrogen plasma determined from radiative transitions of N2+ was 3800–5700 K. From a comparison of the gas temperature and the incident microwave power, it was found that the reaction efficiency for fullerenes decreases with the increase in the gas temperature of the plasma and shows a maximum at about 4500 K.
Photolysis in the NH3-NO system was studied by using an ArF-excimer laser. It was found that the concentration of NO decreases during laser irradiation for a mixture of gaseous of NH3 and NO. From a quadrupole-mass spectroscopic analysis of the gases, the decomposition of NO molecules yields selectively H2O and N2 molecules. The dependence of quantum yield of NO decomposition on the concentration of NH3 shows a maximum at the same concentration as that of NO.
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