痕量挥发性有机物在线质谱PTR-MS高灵敏检测方法研究

As the most powerful real-time and on-line detection mass spectrometry, the proton transfer reaction mass spectrometer (PTR-MS) has been used for on-site monitoring of atmospheric volatile organic compounds in various platforms such as airborne, vehicles and boats. Meanwhile, PTR-MS is also cross-applied to many field frontiers including food hygiene, national security, biology and medical health. The applicant's group has established domestic first usable PTR-MS experimental apparatus. However, due to the performance limitation by the quadrupole rods, the current detection limit is around 200 ppt. To solve these problems, this project proposes to develop high sensitive measurement method for online mass spectrometry PTR-MS: under circumstance of unchanging the mass detector, through a tandem combination of the funnel-shaped ion source and the funnel-shaped ion reaction drift tube, due to an ion funnel's ion focusing, the densities of reactant ions and product ions will be increased by more than 10 times respectively, which would result in PTR-MS detection sensitivity increased over 100 times. Thus, the detection limit of PTR-MS device is expected to be better than 1ppt, reaching the most advanced level in the world. In addition, in combination with GC-MS/MS machine, such a PTR-MS device will be used to detect air, the headspace of food or pharmaceutical packaging so as to learn the status information about ultra-trace volatile organic compounds and to demonstrate its high sensitivity detection feature and new technique superiority.

质子转移反应质谱PTR-MS是当今流行的实时在线质谱技术，国际上，以机载、车载、船载等形式被用于大气挥发性有机物的现场监测，该技术也正交叉应用到食品卫生、国家安全、生物以及医疗健康等前沿领域。申请人研究组已建立了国内第一套可运行的PTR-MS实验装置，受四极杆性能的限制，目前的检测限在200ppt。为此，本项目拟开展在线质谱PTR-MS高灵敏检测新方法研究：在不改变质谱探测器的前提下，通过具有离子聚焦功能的漏斗状离子源和漏斗状离子反应漂移管的串联，将反应离子和产物离子强度分别提高10倍以上，从而将PTR-MS的检测灵敏度提高100倍以上，检测限预期将优于1ppt，将达到世界先进水平。同时，结合标准化的GC-MS/MS技术，开展大气、食品和药品包装顶空气体检测实验研究，获取超痕量挥发性有机物状况信息，展现PTR-MS高灵敏检测功能与技术优势。

申请人所在单位于2008年研制了国内第一套可运行的质子转移反应质谱仪PTR-MS，本项目开展了PTR-MS高灵敏检测新方法研究。借助计算模拟，设计并研制了具有聚焦功能的离子源/离子反应迁移管PTR-MS，通过仪器参数的系统优化，将PTR-MS检测的离子信号强度提高了4~155倍，基本实现了PTR-MS 检测灵敏度提高100 倍以上的研究目标。结合GC-MS分析，运用PTR-MS成功地开展了大气、食品和药品包装顶空气体中痕量VOC的高灵敏检测。项目中掌握的高灵敏关键技术，为提升国产PTR-MS仪器智造水平打下了科学基础。