Speciated measurements of semivolatile and intermediate volatility organic compounds (S/IVOCs) in a pine forest during BEACHON-RoMBAS 2011
Speciated measurements of semivolatile and intermediate volatility organic compounds (S/IVOCs) in a pine forest during BEACHON-RoMBAS 2011
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DOI：
10.5194/acp-16-1187-2016
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发表时间：
2016-01-01
影响因子：
6.3
通讯作者：
Goldstein, A. H.
中科院分区：
文献类型：
--
作者：
Chan, A. W. H.;Kreisberg, N. M.;Goldstein, A. H.
了解气体和颗粒的有机组成对于确定有机气溶胶（OA）的来源和大气过程至关重要，但大气化学的复杂性和现有的分析技术往往限制了这种分析。在这里，我们使用一种新型的两用仪器（sv - tags - ams），在能源、气溶胶、碳、水、有机物和氮的生物-水-大气相互作用-落基山生物气溶胶研究（BEACHON-RoMBAS） 2011活动期间，在CO . Manitou Forest部署了半挥发性和中间挥发性有机化合物（S/IVOCs）的特定测量。该仪器提供环境有机化合物的在线形态与2小时的时间分辨率。在这个挥发性范围内的物质组成复杂，但它们的化学特性揭示了潜在的来源。观察到的生物源性化合物包括分子式为C15H24的倍半萜（如-石蜡烯和长叶烯），它们在夜间含量最高。还观察到多种其他生物源化合物，包括分子式为C15H22的倍半萜类化合物、二萜烯等萜类化合物。许多这些化合物已经在精油和分支封闭研究中发现，但在我们的研究中首次在环境空气中观察到。半挥发性多环芳烃（PAHs）和烷烃的浓度在白天最高，对温度的依赖表明蒸发源的作用。利用正矩阵分解（PMF）的统计分析方法，将观测到的S/IVOCs按其可能的来源和过程进行分类，并根据化学成分对其进行表征。可洗脱S/IVOCs的总质量浓度估计约为0.7 μ g m(-3)，其挥发性分布估计用于模拟气溶胶形成化学。
Understanding organic composition of gases and particles is essential to identifying sources and atmospheric processing leading to organic aerosols (OA), but atmospheric chemical complexity and the analytical techniques available often limit such analysis. Here we present speciated measurements of semivolatile and intermediate volatility organic compounds (S/IVOCs) using a novel dual-use instrument (SV-TAG-AMS) deployed at Manitou Forest, CO, during the Bio-hydro-atmosphere interactions of Energy, Aerosols, Carbon, H2O, Organics & Nitrogen - Rocky Mountain Biogenic Aerosol Study (BEACHON-RoMBAS) 2011 campaign. This instrument provides on-line speciation of ambient organic compounds with 2 h time resolution. The species in this volatility range are complex in composition, but their chemical identities reveal potential sources. Observed compounds of biogenic origin include sesquiterpenes with molecular formula C15H24 (e.g., beta-caryophyllene and longifolene), which were most abundant at night. A variety of other biogenic compounds were observed, including sesquiterpenoids with molecular formula C15H22, abietatriene and other terpenoid compounds. Many of these compounds have been identified in essential oils and branch enclosure studies but were observed in ambient air for the first time in our study. Semivolatile polycyclic aromatic hydrocarbons (PAHs) and alkanes were observed with highest concentrations during the day and the dependence on temperature suggests the role of an evaporative source. Using statistical analysis by positive matrix factorization (PMF), we classify observed S/IVOCs by their likely sources and processes, and characterize them based on chemical composition. The total mass concentration of elutable S/IVOCs was estimated to be on the order of 0.7 mu g m(-3) and their volatility distributions are estimated for modeling aerosol formation chemistry.