Relative rate constants for the heterogeneous reactions of NO2 and OH radicals with polycyclic aromatic hydrocarbons adsorbed on carbonaceous particles.: Part 2:: PAHs adsorbed on diesel particulate exhaust SRM 1650a
Relative rate constants for the heterogeneous reactions of NO2 and OH radicals with polycyclic aromatic hydrocarbons adsorbed on carbonaceous particles.: Part 2:: PAHs adsorbed on diesel particulate exhaust SRM 1650a
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DOI：
10.1016/j.atmosenv.2005.07.053
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发表时间：
2006-01-01
影响因子：
5
通讯作者：
Villenave, E
中科院分区：
文献类型：
--
作者：
Esteve, W;Budzinski, H;Villenave, E
研究了柴油机排气微粒(NIST SRM 1650a)中天然存在的多环芳烃(PAHs)与NO2和OH自由基的非均相反应。利用快速流动反应器，通过跟踪颗粒物-多环芳烃浓度随反应时间的衰减，确定了相对降解速率常数。定量分析采用气相色谱-质谱联用内标法进行。相对速率常数表明，多环芳烃与NO2的反应具有明显的结构反应性效应。Py和苯并(A)Py与NO2的反应活性最强，而所研究的所有多环芳烃在不确定度范围内与OH的反应活性相似。所有多环芳烃与OH的反应性似乎比与NO2的反应性高约四个数量级。这些速率常数证实了与NO2相比，多环芳烃在大气中的主要损失过程是以OH多相反应为主。我们的数据与以前的文献研究进行了比较。关于颗粒和气相。这项工作表明，多环芳烃在气相中的反应性将显著大于与碳质颗粒底物相关的反应性。(C)2005爱思唯尔有限公司。保留所有权利。
The heterogeneous reactions of NO2 and OH radicals with polycyclic aromatic hydrocarbons (PAHs) naturally present in diesel particulate exhaust (NIST SRM 1650a) have been investigated. Using a fast flow reactor, relative degradation rate constants have been determined by following the decays of particulate-PAH concentrations vs. the reaction time. Quantitative analyses have been performed by gas chromatography coupled to mass spectrometry detection using internal standards. Relative rate constants show a significant structure reactivity effect for the reaction of PAHs with NO2. Pyrene and benzo(a)pyrene are the most reactive with NO2 whereas all PAHs studied present similar reactivities with OH within uncertainties. All PAHs appeared to be approximately four orders of magnitude more reactive with OH than with NO2. These rate constants confirm that the OH heterogeneous reaction will be the dominant atmospheric loss process of PAHs compared to that with NO2. Our data are compared to previous literature studies. concerning both the particulate and the gas phases. This work demonstrates that the reactivity of PAHs in the gas phase would be significantly larger than when associated with carbonaceous particulate substrates. (c) 2005 Elsevier Ltd. All rights reserved.