ON-SITE REAL-TIME MONITORING OF DIOXINS AND RELATED COMPOUNDS

我们研制了一种灵敏的实时监测二恶英的分析仪器，并利用该分析仪器进行了基础研究。结果，多光子电离的效率大大降低。为了克服这个问题，有必要使用脉冲宽度与分析物分子寿命相似的激光器。这一预期从理论和实验两方面都得到了证实。在这项工作中，我们开发了一台脉冲宽度为皮秒的分布反馈染料激光器，并证实了使用该激光器可以获得高的电离效率。为了提高二恶英分析的灵敏度，需要使用能够有效检测由多光子电离引起的离子的质谱仪。在…中设计了一种新型的质谱计此外，这项研究和预期的性能是使用SIMION软件计算的。我们还构建了这个质谱仪，并通过实验证实了它具有足够的性能来灵敏地检测二恶英及其前体。在这项工作中，我们用超声波喷射光谱仪测量了聚氯乙烯的热分解产物。研究发现，聚氯乙烯不生成二恶英前体，而氯化聚氯乙烯(聚偏二氯乙烯)主要生成氯苯前体。我们还研究了氯代酚在FeCl3催化剂存在和无催化作用下生成二恶英的反应机理。发现了一种意想不到的二恶英异构体，它是通过“微笑重排”形成的。用传统的质谱计很难实时监测S的特定异构体，因此我们可以展示超声喷射/多光子电离/质谱仪相对于传统质谱学的优势。我们的项目《二恶英在线实时监测分析仪器的研制》在2000-2002年期间被国家能源局接受。开发的分析仪器计划从2003年开始商业化。较少

We developed an analytical instrument for sensitive real-time monitoring of dioxins and investigated basic researches using this analytical instrument.The lifetimes of the electronic excited state of aromatic hydrocarbons containing many chlorine atoms such as dioxins are shortened by a spin-orbit interaction. As a result of this, the efficiency of multiphoton ionization is substantially reduced. In order to overcome this problem, it is necessary to use a laser whose pulsewidth is similar to the lifetime of the analyte molecule. This expectation was confirmed from both sides of theory and experiment. In this work, we developed a distributed-feedback dye laser having a picosecond pulsewidth and confirmed that a high ionization efficiency was obtained using this laser.In order to improve the sensitivity in dioxin analysis, it is desirable to use a mass spectrometer which allows efficient detection of ions induced by multiphoton ionization. A new type of mass spectrometer was designed in … More this study and performance expected was calculated using a SIMION software. We also constructed this mass spectrometer and confirmed experimentally to have sufficient performance for sensitive detection of dioxins and their precursors.In this work, we measured thermally decomposed ploducts of polyvinylchloride by supersonic jet spectrometry. It was found that no dioxin precursors are formed from polyvinylchloride, while a precursor of chlorobenzene is formed as a major product from chlorinated polyvinylchloride (polyvinylidene). We also investigated the reaction mechanism of dioxins induced from chlorophenols in the absence and presence of a catalyst of FeCl_3. An unexpected isomer of dioxin was found, which was formed through the "Smile Rearrangement". Real-time monitoring of s pecific isomer is difficult using a conventional mass spectrometer, and hence we could demonstrate the advantage of supersonic jet/multiphoton ionization/mass spectrometry over conventional mass spectrometry.Our proposal entitled, "Development of analytical instrument for on-line real-time monitoring of dioxins" was accepted by NEDO in the period of 2000-2002. The analytical instrument developed is scheduled to be commercialized from 2003. Less