Characteristics of 2-methyltetrols in ambient aerosol in Beijing, China

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• 作者：Linlin Liang ; Guenter Engling ; Fengkui Duan ; Yuan Cheng ; Kebin He
• 关键词：2-Methyltetrols ; Seasonal variation ; Biogenic SOA ; Isoprene oxidation ; HPAEC
• 刊名：Atmospheric Environment
• 出版年：2012
• 出版时间：November, 2012
• 年：2012
• 卷：59
• 期：Complete
• 页码：376-381
• 全文大小：726 K

文摘

PM₁₀ and PM_2.5 samples were collected from November, 2010 to October, 2011 at Tsinghua University in Beijing. Various carbohydrates were quantified by high-performance anion exchange chromatography with pulsed amperometric detection (HPAEC-PAD), including the 2-methyltetrols (2-methylthreitol and 2-methylerythritol). A clear seasonal variation in the ambient 2-methyltetrol concentrations was observed, with the highest levels occurring in the summer, followed by autumn, spring and winter. The average concentrations of the 2-methyltetrols in PM₁₀ and PM_2.5 were 17.5?¡À?15.4?ng?m^?3 and 13.8?¡À?12.2?ng?m^?3, respectively. The 2-methyltetrols exhibited significant positive correlations with ambient relative humidity and temperature, likely due to the higher isoprene emission strength and enhanced formation yield under higher temperature and humidity conditions. In contrast, there was no relationship between the concentration of 2-methyltetrols and sunshine duration. The significant positive correlation (R²?=?0.76) between 2-methyltetrols and SO₄^2? indicated that high concentrations of SO₄^2? can increase the formation rate of 2-methyltetrols from isoprene. Moreover, 2-methyltetrols were also observed in the winter time in Beijing, illustrating the enhancement of the 2-methyltetrol formation rate by high concentrations of pollutants in ambient aerosol.