State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry (LAPC), Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China; Key Laboratory of Eco-environments in Three Gorges Reservoir Region, Ministry of Education, College of Resources and Environment, Southwest University, Chongqing 400716, China.
State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry (LAPC), Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China.
J Environ Sci (China). 2018 Jan;63:16-27. doi: 10.1016/j.jes.2017.03.036. Epub 2017 Apr 8.
In this study, we performed a highly time-resolved chemical characterization of non-refractory submicron particles (NR-PM) in Beijing by using an Aerodyne high-resolution time-of-flight aerosol mass spectrometer (HR-ToF-AMS). The results showed the average NR-PM mass concentration to be 56.4±58.0μg/m, with a peak at 307.4μg/m. Due to the high frequency of biomass burning in autumn, submicron particles significantly increased in organic content, which accounted for 51% of NR-PM on average. Secondary inorganic aerosols (sulfate+nitrate+ammonium) accounted for 46% of NR-PM, of which sulfate, nitrate, and ammonium contributed 15%, 20%, and 11%, respectively. To determine the intrinsic relationships between the organic and inorganic species, we used the positive matrix factorization (PMF) model to merge the high-resolution mass spectra of the organic species and NO and NO ions. The PMF analysis separated the mixed organic and nitrate (NO and NO) spectra into four organic factors, including hydrocarbon-like organic aerosol (HOA), oxygenated organic aerosol (OOA), cooking organic aerosol (COA), and biomass burning organic aerosol (BBOA), as well as one nitrate inorganic aerosol (NIA) factor. COA (33%) and OOA (30%) contributed the most to the total organic aerosol (OA) mass, followed by BBOA (20%) and HOA (17%). We successfully quantified the mass concentrations of the organic and inorganic nitrates by the NO and NO ions signal in the organic and NIA factors. The organic nitrate mass varied from 0.01-6.8μg/m, with an average of 1.0±1.1μg/m, and organic nitrate components accounted for 10% of the total nitrate mass in this observation.
在这项研究中，我们使用 Aerodyne 高分辨率飞行时间气溶胶质谱仪（HR-ToF-AMS）对北京的非难熔亚微米颗粒（NR-PM）进行了高度时间分辨的化学特性分析。结果表明，NR-PM 的平均质量浓度为 56.4±58.0μg/m，峰值为 307.4μg/m。由于秋季生物质燃烧频率较高，亚微米颗粒中的有机含量显著增加，平均占 NR-PM 的 51%。二次无机气溶胶（硫酸盐+硝酸盐+铵）占 NR-PM 的 46%，其中硫酸盐、硝酸盐和铵分别占 15%、20%和 11%。为了确定有机和无机物种之间的内在关系，我们使用正定矩阵因子分解（PMF）模型将有机物种和 NO 和 NO 离子的高分辨率质谱合并。PMF 分析将混合有机和硝酸盐（NO 和 NO）光谱分为四个有机因子，包括烃类有机气溶胶（HOA）、含氧有机气溶胶（OOA）、烹饪有机气溶胶（COA）和生物质燃烧有机气溶胶（BBOA），以及一个硝酸盐无机气溶胶（NIA）因子。COA（33%）和 OOA（30%）对总有机气溶胶（OA）质量的贡献最大，其次是 BBOA（20%）和 HOA（17%）。我们成功地通过有机和 NIA 因子中的 NO 和 NO 离子信号量化了有机和无机硝酸盐的质量浓度。有机硝酸盐的质量浓度在 0.01-6.8μg/m 之间，平均值为 1.0±1.1μg/m，有机硝酸盐成分占该观测中总硝酸盐质量的 10%。
