Molecular Composition and Volatility of Nucleated Particles from α-Pinene Oxidation between −50 °C and +25 °C
Molecular Composition and Volatility of Nucleated Particles from α-Pinene Oxidation between −50 °C and +25 °C
复制标题
α-蒎烯氧化成核颗粒在 50 °C 至 25 °C 温度下的分子组成和挥发性
DOI：
10.1021/acs.est.9b03265
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发表时间：
2019
影响因子：
11.4
通讯作者：
Brilke, Sophia
中科院分区：
文献类型：
--
作者：
Ye, Qing;Wang, Mingyi;Hofbauer, Victoria;Stolzenburg, Dominik;Chen, Dexian;Schervish, Meredith;Vogel, Alexander;Mauldin, Roy L.;Baalbaki, Rima;Brilke, Sophia
我们使用实时控温解吸化学电离质谱仪（FIGAERO-CIMS）测量粒子相组成和成核粒子的挥发性，研究了CERN CLOUD室在- 50°C至+25°C的宽温度范围内纯α-蒎烯氧化。在高温下形成的颗粒中，高氧有机分子的含量要高得多，这使得化合物的O/C值更高，本征挥发性（300 K）更低。我们发现纯生物成核和生长对温度的依赖性很弱。这是因为氧化度（和极性）的正温度依赖性和挥发性的负温度依赖性相互抵消。与之前依赖于估计挥发性的工作不同，我们通过校准的温度程序解吸直接测量挥发性。我们的颗粒相测量结果与气相结果一致，表明在α-蒎烯氧化形成新颗粒的过程中，气相化学直接决定了凝聚相中材料的性质。我们现在在测量的气相产物浓度、产物挥发性、测量和模拟的增长率以及对流层中大多数温度下的颗粒组成之间有了一致性。
We use a real-time temperature-programmed desorption chemical-ionization mass spectrometer (FIGAERO–CIMS) to measure particle-phase composition and volatility of nucleated particles, studying pure α-pinene oxidation over a wide temperature range (−50 °C to +25 °C) in the CLOUD chamber at CERN. Highly oxygenated organic molecules are much more abundant in particles formed at higher temperatures, shifting the compounds toward higher O/C and lower intrinsic (300 K) volatility. We find that pure biogenic nucleation and growth depends only weakly on temperature. This is because the positive temperature dependence of degree of oxidation (and polarity) and the negative temperature dependence of volatility counteract each other. Unlike prior work that relied on estimated volatility, we directly measure volatility via calibrated temperature-programmed desorption. Our particle-phase measurements are consistent with gas-phase results and indicate that during new-particle formation from α-pinene oxidation, gas-phase chemistry directly determines the properties of materials in the condensed phase. We now have consistency between measured gas-phase product concentrations, product volatility, measured and modeled growth rates, and the particle composition over most temperatures found in the troposphere.