Thermal Desorption/Tunable Vacuum-Ultraviolet Time-of-Flight Photoionization Aerosol Mass Spectrometry for Investigating Secondary Organic Aerosols in Chamber Experiments
Thermal Desorption/Tunable Vacuum-Ultraviolet Time-of-Flight Photoionization Aerosol Mass Spectrometry for Investigating Secondary Organic Aerosols in Chamber Experiments
复制标题
热解吸/可调真空紫外飞行时间光电离气溶胶质谱法用于研究室内实验中的二次有机气溶胶
DOI：
10.1021/ac201838e
复制
发表时间：
2011-12-01
影响因子：
7.4
通讯作者：
Sheng, Liusi
中科院分区：
文献类型：
--
作者：
Fang, Wenzheng;Gong, Lei;Sheng, Liusi
本文介绍了热解吸/可调真空紫外光电离飞行时间气溶胶质谱仪 (TD-VUV-TOF-PIAMS)，用于烟雾室实验中二次有机气溶胶 (SOA) 的实时分析。 SOA 直接从大气压力中采样，并通过空气动力透镜组件聚焦到质谱仪中。一旦粒子进入源区域，它们就会撞击加热器并被蒸发。然后新生蒸气被可调谐 VUV 同步加速器辐射轻轻电离。 TD-VUV-TOF-PIAMS 与烟雾室结合使用，研究甲苯与羟基自由基光氧化形成 SOA。这些 SOA 产品的电离能 (IE) 有时彼此差异很大。由于理想光子源是可调的，因此可以针对每个要电离的分子调整其能量。在不同光子能量下获得的质谱可用于分子识别。 SOA 质谱的实时分析与之前的离线测量进行了比较。这些结果说明了 TD-VUV-TOF-PIAMS 在烟雾室实验中直接对 SOA 进行分子表征的潜力。
This paper describes thermal desorption/tunable vacuum-ultraviolet photoionization time-of-flight aerosol mass spectrometry (TD-VUV-TOF-PIAMS) for the real-time analysis of secondary organic aerosols (SOAs) in smog chamber experiments. SOAs are sampled directly from atmospheric pressure and are focused through an aerodynamic lens assembly into the mass spectrometer. Once the particles have entered the source region, they impact on a heater and are vaporized. The nascent vapor is then softly ionized by tunable VUV synchrotron radiation. TD-VUV-TOF-PIAMS was used in conjunction with the smog chamber to study SOA formation from the photooxidation of toluene with hydroxyl radicals. The ionization energies (IEs) of these SOA products are sometimes very different with each other. As the ideal photon source is tunable, its energy can be adjusted for each molecular to be ionized. The mass spectra obtained at different photon energies are then to be useful for molecular identification. Real-time analysis of the mass spectra of SOAs is compared with previous off-line measurements. These results illustrate the potential of TD-VUV-TOF-PIAMS for direct molecular characterization of SOAs in smog chamber experiments.