The aerosol size distribution of organic compounds is one of the fundamental characteristics that regulates their atmospheric deposition and environmental fate. In this study, we characterized the organic components (mostly nonpolar organic compounds) in size‐resolved particles, with a focus on polycyclic aromatic hydrocarbons (PAHs), oxygenated PAHs (O‐PAHs), n‐alkanes, and polybrominated diphenyl ethers (PBDEs), in the urban Shanghai atmosphere during a 1‐year sampling period using gas chromatography (GC) coupled to tandem mass spectrometry (GC‐MS/MS) and two‐dimensional GC with a flame ionization detector (GC × GC‐FID). These compounds ranged from volatile organic compounds (VOCs) to extremely low volatility organic compounds (ELVOCs). We related their aerosol size distributions with their volatilities. On average, high positive correlations (p  < 0.01) were observed between the size distribution characteristics (e.g., geometric mean diameter [GMD] and mass fraction in coarse particles) and volatility (logarithmic value of the saturation mass concentration, log C ^* ) for the compounds that we examined. A higher ambient temperature tends to increase the slope of the regression line between size distribution and volatility (log C ^* ). Further dry deposition modeling of size‐resolved particles showed a positive correlation (p  < 0.01) between the bulk dry deposition velocity and GMD and between the bulk dry deposition velocity and volatility of the target compounds, indicating that low‐volatility organic compounds have a lower dry deposition velocity and are more likely to be transported to remote areas if they do not have a short half‐life in the atmosphere.

中文翻译：

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非极性有机化合物气溶胶粒径分布的挥发性依赖性：以上海为例

有机化合物的气溶胶尺寸分布是调节其大气沉积和环境命运的基本特征之一。在这项研究中，我们对尺寸分离颗粒中的有机成分（主要是非极性有机化合物）进行了表征，重点研究了多环芳烃（PAH），氧化型PAH（O-PAH），正烷烃和多溴联苯醚（PBDEs） ），在气相色谱（GC）结合串联质谱（GC-MS / MS）和带有火焰离子化检测器（GC×GC-FID）的二维GC的1年采样期内，在上海城市大气中。这些化合物的范围从挥发性有机化合物（VOC）到极低挥发性的有机化合物（ELVOC）。我们将它们的气溶胶粒径分布与其挥发性联系起来。平均而言，高正相关（ 在我们研究的化合物的尺寸分布特征（例如，几何平均直径[GMD]和粗颗粒中的质量分数）与挥发性（饱和质量浓度的对数值，log C ^*）之间观察到p <0.01 。较高的环境温度往往会增加尺寸分布和挥发性之间的回归线斜率（log C ^*）。尺寸分辨颗粒的进一步干法沉积模型显示出正相关（p <0.01）在目标化合物的总干沉降速度和GMD之间以及总干沉降速度和挥发性之间，这表明低挥发性有机化合物的干沉降速度较低，如果将其运输到偏远地区大气中的半衰期不短。