研究报告

  • 徐俊,黄明强,冯状状,蔡顺有,赵卫雄,胡长进,顾学军,张为俊.氨对甲苯二次有机气溶胶形成和化学组分的影响研究[J].环境科学学报,2018,38(8):3243-3251

  • 氨对甲苯二次有机气溶胶形成和化学组分的影响研究
  • Experimental study the effects of ammonia on the formation and chemical composition of toluene secondary organic aerosol
  • 基金项目:国家自然科学基金(No.41575118,41305109);福建省自然科学基金(No.2015J06009)
  • 作者
  • 单位
  • 徐俊
  • 闽南师范大学化学与环境学院, 福建省现代分离分析科学与技术重点实验室, 漳州 363000
  • 黄明强
  • 闽南师范大学化学与环境学院, 福建省现代分离分析科学与技术重点实验室, 漳州 363000
  • 冯状状
  • 闽南师范大学化学与环境学院, 福建省现代分离分析科学与技术重点实验室, 漳州 363000
  • 蔡顺有
  • 闽南师范大学化学与环境学院, 福建省现代分离分析科学与技术重点实验室, 漳州 363000
  • 赵卫雄
  • 中国科学院安徽光学精密机械研究所大气物理化学实验室, 合肥 230031
  • 胡长进
  • 中国科学院安徽光学精密机械研究所大气物理化学实验室, 合肥 230031
  • 顾学军
  • 中国科学院安徽光学精密机械研究所大气物理化学实验室, 合肥 230031
  • 张为俊
  • 中国科学院安徽光学精密机械研究所大气物理化学实验室, 合肥 230031
  • 摘要:氨(NH3)是大气中常见的主要碱性污染气体,能够影响二次有机气溶胶(SOA)的形成和化学组分.本文利用自制的烟雾腔系统开展了NH3对甲苯SOA形成和化学组分的影响研究,先后采用扫描移动粒径谱仪(SMPS)、气溶胶激光飞行时间质谱仪(ALTOFMS)、紫外-可见分光光度计(UV-Vis)、衰减全反射傅里叶变换红外光谱仪(ATR-FTIR)和荧光光谱仪(MF)测量反应产生的SOA粒子的物理化学性质.结果显示,在光照60 min的时间范围内,有NH3条件下形成的SOA质量浓度和中心粒径相比于无NH3条件下分别增加了50%和25%,这说明NH3能够显著促进甲苯SOA的形成.与无NH3条件下相比,NH3存在时甲苯SOA化学组分的紫外可见吸收光谱在270 nm处有明显的吸收峰;红外吸收光谱出现了C=N、C—N、N—H键的吸收峰;激光解吸附质谱图中含有m/z=67(C3H3N2+)、m/z=41(C2H2N+)和m/z=28(CH2N+)碎片峰.这些谱图信息综合表明是NH3和甲苯SOA中的二醛组分反应形成了咪唑类新产物.这为研究人为源SOA的形成机制提供了实验依据.
  • Abstract:Ammonia (NH3) is the primary alkaline pollution gas commonly found in the atmosphere that can affect the formation and chemical composition of secondary organic aerosols (SOA) in atmosphere. The effects of NH3 on the formation and chemical composition of toluene secondary organic aerosols (SOA) were investigated using home-made smog chamber system in this study. The physical and chemical properties of the formed SOA particles were measured by using scanning mobile particle size spectrometer (SMPS), aerosol laser time of flight mass spectrometry (ALTOFMS), ultraviolet visible spectrophotometer (UV-Vis), attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) and fluorescence spectroscopy (MF), respectively. Compared to without NH3,the higher mass concentration and central particle size of SOA (increased by 50% and 25%, respectively) after 60 minutes of light under NH3 conditions indicated that NH3 could significantly promote the formation of toluene SOA, Meanwhile, the UV-Vis absorption spectrum of toluene SOA in the presence of NH3 showed obvious absorption peak at 270 nm. The absorption peak of C=N, C-N and N-H bond appeared in its infrared absorption spectrum. Also, the laser desorption mass spectra of toluene SOA with NH3 obtained by ALTOFMS contained fragment peaks at m/z 28 (CH2N+), 41 (C2H2N+) and 67 (C3H3N2+). These spectral information indicated that imidazole compounds newly formed via NH3 reaction with dialdehyde component of toluene SOA. These would provide experimental basis for the formation mechanism of anthropogenic SOA studying.

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