FASTOF: Fully automated in-situ GC-TOF Observation of atmospheric trace gases

卤代烃化合物在大气化学、平流层臭氧消耗和大气辐射强迫中起着重要作用。它们最常用的测量方法是气相色谱-四极质谱联用。我们建议开发一种新的测量系统，其中的四极质谱仪是由一个更强大的飞行时间质谱仪，最近已成为可用的形式，这是适合现场部署。这种新的质谱仪的主要优点是它达到了四极质谱仪的灵敏度，四极质谱仪被调谐到单个质量，但同时提供了所有质量的信息（全扫描模式）。我们建议完全自动化这个仪器，以便能够部署在远程现场。在仪器研制的早期阶段就可以进行首次大气观测，而在第二个项目年之后将具备完全自动化的测量能力。我们建议在三个科学领域利用这一仪器进行首次测量，重点是大气中的卤代烃：（i）测量可能影响平流层臭氧的溴化和碘化卤化碳的来源区域、海洋边界层，（ii）利用该仪器的扫描能力寻找大气中新的、迄今尚未查明的卤代烃，（iii）测量氢氟碳化合物，因为氢氟碳化合物在未来可能成为更为重要的温室气体，并利用飞行时间质谱仪的扫描能力建立一个空气档案，以便对迄今尚未查明的物种进行量化，通过本文的工作，我们希望建立一种用于大气痕量气体测量的GC-TOF技术，这将在未来提供更详细的信息。可以预见，这一工具在国家和国际项目中还有许多进一步的应用，例如，研究非二氧化碳温室气体和消耗臭氧层的化学品、其大气趋势、汇和源、分布、变异性及其对大气化学和气候的影响。

Halocarbon compounds play an essential role in atmospheric chemistry, in the depletion ofstratospheric ozone and in radiative forcing of the atmosphere. They are most commonlymeasured by gas chromatography coupled to quadrupole mass spectrometry. We propose todevelop a novel measurement system, in which the quadrupole mass spectrometer is replacedby a much more powerful time-of-flight mass spectrometer, which has recently becomeavailable in a form which is suited for field deployment. The main advantage of this newlyavailable mass spectrometer is that it achieves the sensitivity of a quadrupole massspectrometer which is tuned to a single mass, but in the same time provides information on allmasses (full scan mode). We suggest to fully automate this instrument in order to be able todeploy it at remote field sites. First atmospheric observations will already be possible at anearly stage of the instrument development, while fully automated measurement capability willbe available after the second project year.We suggest three scientific areas for the first measurements with this instrument, focussing onhalogenated hydrocarbons in the atmosphere: (i) measure brominated and iodinatedhalocarbons which may impact stratospheric ozone in their source region, the marineboundary layer, (ii) use the scanning capability of the instrument to search for new, so farunidentified halocarbons in the atmosphere and (iii) measure hydrofluorocarbons, which couldbecome much more important greenhouse gases in the future and use the scanning capabilitiesof the TOF mass spectrometer in order to create an air archive allowing to quantify so farunidentified species, even at a later stage.With the work proposed here we would like to establish the GC-TOF technique foratmospheric trace gas measurements, which will provide much more detailed information inthe future. Many further applications of this instrument in national and international projectsare foreseeable, e.g. for studies of non-CO2 greenhouse gases and ozone depleting chemicals,their atmospheric trends, sinks and sources, distributions, variabilities and their impact onchemistry and climate of the atmosphere.