U.S.-U.K. Cooperative Research: Atmospheric Oxidation of Dimethyl Sulphide

该奖项将支持佐治亚理工学院的Anthony J.Hynes博士和英国利兹大学化学学院的D.L.Bauch博士在大气化学方面的合作研究。本研究的目的是利用流动放电技术研究二甲基硫醚常压氧化的动力学和机理。众所周知，二甲基硫是由海洋生物排放的，被认为是海洋环境中气溶胶和云形成的前驱物质；因此，它对研究全球气候特别有意义。实验将利用放电流动装置，结合激光诱导荧光和质谱学检测反应中间体和反应产物。使用校准的激光诱导荧光，同时观察反应物损失和产物形成，可以建立甲基硫化物自由基和二氧化硫在羟基引发的二甲基硫化物氧化反应中的定量产率。将尝试建立用于检测稳定反应产物的质谱学采样的可行性。该项目将受益于海恩斯博士在分子束、大气采样和大气动力学方面开发激光诊断技术的专业知识。英国合作者鲍赫博士在应用放电流动技术研究氧和羟基自由基反应方面拥有多年的经验。这项研究的结果应有助于理解全球大气化学中的硫循环。

This award will support collaborative research in atmospheric chemistry between Dr. Anthony J. Hynes, Georgia Institute of Technology and Dr. D.L. Bauch, School of Chemistry, University of Leeds, England. The objective of the proposed research is to study the kinetics and mechanisms of the atmospheric oxidation of dimethyl sulfide using flow discharge techniques. Dimethyl sulfide is known to be emitted by marine organisms and has been suggested to be a precursor to aerosol and cloud formation in marine environments; it is therefore of particular interest for the study of global climate. Experiments will utilize a discharge flow apparatus coupled with laser induced fluorescence and mass spectrometric detection of reactive intermediates and reaction products. Use of calibrated laser induced fluorescence and simultaneous observation of reactant loss and product formation should allow quantitative yields of methyl sulfide radical and sulfur dioxide from the hydroxyl radical initiated oxidation of dimethyl sulfide to be established. Attempts will be made to establish the feasibility of mass spectrometric sampling for the detection of stable reaction products. The project will benefit from the expertise of Dr. Hynes in the development of laser diagnostic techniques in molecular beams, atmospheric sampling and atmospheric kinetics. The British collaborator Dr. Bauch has many years of experience in the application of discharge flow technique to the study of oxygen and hydroxyl radical reactions. The results of this research should contribute to the understanding of the sulphur cycle in global atmospheric chemistry.