Laboratory Studies of Tropospheric Sulfur Chemistry

本研究计画为一实验室研究，旨在阐明控制含硫化合物大气氧化的动力学与反应机制。 本项目的重点是二甲硫醚（DMS，CH 3SCH 3）及其中间氧化产物二甲亚砜（DMSO，CH 3S（O）CH 3）和甲烷亚磺酸（MSIA，CH 3S（O）OH）的氧化途径。目前，人们对大气硫氧化有相当大的兴趣，以促进我们对（1）冰芯分析解释的过去气候和（2）硫在大气中颗粒形成和生长中的作用及其对当前和未来气候的影响的理解。 具体的实验研究包括：（1）BrO自由基与DMS、DMSO反应的动力学和机理研究，以及Cl、Br和O原子与DMSO反应的动力学和机理研究，（2）CH_3SCH_2 OO + HO_2自由基-自由基反应的动力学和机理研究，（3）CH_3SCH_2 OO + HO_2自由基-自由基反应的动力学和机理研究，（4）CH_3SCH_2 OO + HO_2自由基-自由基反应的动力学和机理研究。（3）OH、SO_4 ~-、NO_3、Cl_2 ~-自由基与DMSO、MSIA、MSA、二甲基砜的水相反应研究（DMSO 2，CH 3（O）S（O）CH 3）;（4）MSIA（g）的反应动力学研究;（5）开发用于检测CH 3SOx（x = 1-3）自由基的光学和/或质谱技术。 在本研究过程中，将建造和使用一种新的高压湍流反应器。 流动反应器将与CIMS（化学电离质谱法）、PIMS（光电离质谱法）和TDLAS（可调谐二极管激光吸收光谱法）检测器耦合。

This research project is a laboratory study aimed at elucidating the kinetics and reaction mechanisms which control the atmospheric oxidation of sulfur compounds. The emphasis of this project is on oxidation pathways for dimethylsulfide (DMS, CH3SCH3), and its intermediate oxidation products dimethylsulfoxide (DMSO, CH3S(O)CH3) and methanesulfinic acid (MSIA, CH3S(O)OH). There is currently considerable interest in atmospheric sulfur oxidation in order to facilitate our understanding of (1) past climate as interpreted from ice core analyses and (2) the role sulfur plays in particle formation and growth in the atmosphere and its resulting impact on current and future climate. Specific experimental investigations which will be undertaken include (1) studies of the kinetics and mechanisms of the reactions of BrO radicals with DMS and DMSO, as well as the reactions of Cl, Br, and O atoms with DMSO; (2) a study of the CH3SCH2OO + HO2 radical-radical reaction; (3) studies of the aqueous phase reactions of OH, SO4-, NO3, and Cl2- radicals with DMSO, MSIA, MSA, and dimethylsulfone (DMSO2, CH3(O)S(O)CH3); (4) studies of the reaction kinetics of MSIA(g); and (5) development of optical and/or mass spectrometric techniques for detection of CH3SOx (x = 1-3) radicals. A new, high pressure turbulent flow reactor will be constructed and utilized during the course of this research. The flow reactor will be coupled with CIMS (chemical ionization mass spectrometry, PIMS (photoionization mass spectrometry), and TDLAS (tunable diode laser absorption spectroscopy) detectors.