A model framework to retrieve thermodynamic and kinetic properties of organic aerosol from composition-resolved thermal desorption measurements
A model framework to retrieve thermodynamic and kinetic properties of organic aerosol from composition-resolved thermal desorption measurements
复制标题
从成分分辨热解吸测量中检索有机气溶胶的热力学和动力学特性的模型框架
DOI：
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发表时间：
2018
影响因子：
6.3
通讯作者：
J. Thornton
中科院分区：
文献类型：
--
作者：
S. Schobesberger;E. D’Ambro;F. Lopez‐Hilfiker;C. Mohr;J. Thornton
抽象的。开发出化学电离质谱仪（CIMS）技术
允许对有机物进行定量和成分分辨测量
当化合物从二次有机气溶胶 (SOA) 颗粒中解吸时，
特别是在热诱导蒸发过程中。一种这样的技术采用
气体和气溶胶过滤器入口 (FIGAERO)。在这里，我们推出了一个新的
开发模型框架，主要目的是重现Figaero-CIMS
热分析图：信号与斜坡解吸温度。该模型模拟
受控加热过程中有机化合物的解吸
过滤采样的 SOA 粒子，以及这些粒子的后续传输
化合物通过 FigAERO 歧管进入碘化物-CIMS。解吸是
由修正的 Hertz-Knudsen 方程描述，主要由
与温度相关的饱和浓度 C*，质量调节
（蒸发）系数和颗粒表面积。后续运输是
由与过滤器和歧管表面的相互作用控制。可逆
吸积反应（低聚物形成和分解）和热反应
分解按照阿伦尼乌斯关系进行正式描述。我们使用
校准实验调整仪器特定参数，然后应用
测试用例模型：暗臭氧分解产生的 SOA 测量
α-蒎烯。然后我们讨论模型描述的能力
来自简单校准实验和复杂 SOA 的热分析图，以及
SOA 的化学和物理特性的相关影响。
对于我们的 SOA 测试用例中观察到的主要个体组合 (#C=8
到 10)，热谱图峰通常可以通过分配来描述
C25∘C* 值范围为 0.05 至
5 μg m−3，留下较大的高温部分
(>50 %) 的热分析图通过热描述
分解，解离速率约为 ∼1 h−1
25 ∘C。我们以具体的实验设计来总结，以更好地
约束仪器模型参数并帮助解决剩余问题
对更复杂的 SOA 热分析图行为的解释存在模糊性。
该模型允许检索定量波动和质量传输
来自Figaero热分析图的信息，并用于检查影响
各种环境或化学条件对这些特性的影响。
Abstract. Chemical ionization mass spectrometer (CIMS) techniques have been developed
that allow for quantitative and composition-resolved measurements of organic
compounds as they desorb from secondary organic aerosol (SOA) particles, in
particular during their heat-induced evaporation. One such technique employs
the Filter Inlet for Gases and AEROsol (FIGAERO). Here, we present a newly
developed model framework with the main aim of reproducing FIGAERO-CIMS
thermograms: signal vs. ramped desorption temperature. The model simulates
the desorption of organic compounds during controlled heating of
filter-sampled SOA particles, plus the subsequent transport of these
compounds through the FIGAERO manifold into an iodide-CIMS. Desorption is
described by a modified Hertz–Knudsen equation and controlled chiefly by the
temperature-dependent saturation concentration C*, mass accommodation
(evaporation) coefficient, and particle surface area. Subsequent transport is
governed by interactions with filter and manifold surfaces. Reversible
accretion reactions (oligomer formation and decomposition) and thermal
decomposition are formally described following the Arrhenius relation. We use
calibration experiments to tune instrument-specific parameters and then apply
the model to a test case: measurements of SOA generated from dark ozonolysis
of α-pinene. We then discuss the ability of the model to describe
thermograms from simple calibration experiments and from complex SOA, and the
associated implications for the chemical and physical properties of the SOA.
For major individual compositions observed in our SOA test case (#C=8
to 10), the thermogram peaks can typically be described by assigning
C25∘C* values in the range 0.05 to
5 µg m−3, leaving the larger, high-temperature fractions
(>50 %) of the thermograms to be described by thermal
decomposition, with dissociation rates on the order of ∼1 h−1 at
25 ∘C. We conclude with specific experimental designs to better
constrain instrumental model parameters and to aid in resolving remaining
ambiguities in the interpretation of more complex SOA thermogram behaviors.
The model allows retrieval of quantitative volatility and mass transport
information from FIGAERO thermograms, and for examining the effects of
various environmental or chemical conditions on such properties.
影响因子：
21.8
作者：
Isaacman-VanWertz G;Massoli P;O'Brien R;Lim C;Franklin JP;Moss JA;Hunter JF;Nowak JB;Canagaratna MR;Misztal PK;Arata C;Roscioli JR;Herndon ST;Onasch TB;Lambe AT;Jayne JT;Su L;Knopf DA;Goldstein AH;Worsnop DR;Kroll JH
通讯作者：
Kroll JH