Measurement of the Trends, Behaviors, and Emissions of Trace Gases in the Atmosphere, and its Application to the Analysis in Atmospheric Sciences.

主要研究了以大气稳定氪（Kr）为内标进行大气四氟化碳（CF4）浓度精确测量的分布和趋势。虽然CF4是最强的全球变暖气体，但由于其与空气主要组分的性质接近，在GC/MS分析前的预浓缩过程中，由于捕获效率较差或收集因子不稳定，目前报道的CF4大气浓度测量比年增量或分布梯度具有更大的不确定性。由于预富集和GC/MS测量过程中的物理性质和行为相似，本文建立了一种高效、可重复的预富集方法，并与新采用的大气Kr作为内标相结合。由于Kr在全球大气中均匀且持续存在，没有变化或趋势，因此通过GC/MS测量中的Kr同位素峰对CF4峰进行归一化，可以显著提高CF4测定的精度（从几个百分点提高到不到1%）。所需的样品量也大大减少。利用新采集的样品和实验室保存20多年的样品，获得了对流层和平流层CF4的精确分布和趋势。我们在尝试用大气Kr作为内标精确测定大气中微量气体时，发现半个世纪以来引用的大气Kr浓度1.14±0.01 ppmv与观测值有出入。通过三步浓缩后的GC/MS精确测量，我们得到的Kr浓度为1.099±0.004 ppmv，比目前公认的值低约4%。

Distribution and trend of atmospheric carbon tetrafluoride (CF4) concentration by its precise and accurate measurement adopting atmospheric stable Krypton(Kr) as an internal standard was mainly developed. While CF4 is the strongest global warming gas, the measurement of its atmospheric concentration reported so far contains much larger uncertainties than the annual increment or the distribution gradient due to the worse trapping efficiency or unstable collection factor during the preconcentration process prior to GC/MS analysis because of its close properties to the major components of the air. An efficient and reproducible preconcentration method was developed and combined with the newly adopted atmospheric Kr as an internal standard because of their close physical properties and similar behaviors during the preconcentration and the GC/MS measurement. Since Kr exists uniformly and constantly in the global atmosphere with no variation or trend, extraordinarily improvement of the precision of CF4 determination (from several per cents to less than one per cent) was attained by normalizing the CF4 peak with a Kr isotope peak in the GC/MS measurement. The sample volume necessary was also extremely reduced. The precise and accurate distributions and trends of CF4 in the troposphere and stratosphere were obtained from the samples newly collected and those stored in our laboratory for more than 20 years. During our attempt of the precise determination of trace gases in the atmosphere by using atmospheric Kr as the internal standard, we noticed that the atmospheric Kr concentration of 1.14±0.01 ppmv which had been quoted through half a century was different from the observation. The Kr concentration we obtained with three step concentration followed by precise GC/MS measurement was 1.099±0.004 ppmv, about 4% lower than the currently accepted value.