Characterization of water-soluble organic matter in urban aerosol by (1)H-NMR spectroscopy.
Characterization of water-soluble organic matter in urban aerosol by (1)H-NMR spectroscopy.
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DOI：
10.1016/j.atmosenv.2015.12.067
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发表时间：
2016-03
期刊：
影响因子：
--
通讯作者：
Kavouras IG
中科院分区：
文献类型：
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作者：
Chalbot MG;Chitranshi P;da Costa GG;Pollock E;Kavouras IG
利用核磁共振（1H-NMR）和同位素比值质谱（IRMS）技术对密西西比河流域南部城市大气气溶胶中水溶性有机碳（WSOC）的功能组分和13 C同位素组成进行了测定。利用有机氢的官能团分布、δ 13 C比值和正矩阵因子分解（PMF）解析了WSOC的来源。基于NMR光谱仓加载保留三个因子。两个因素（因素1和3）表现出较强的关联与脂肪区的NMR光谱和左旋葡聚糖共振。两个因子之间的差异包括：因子1的芳香族官能团丰度，表明新鲜排放物;因子3的共振归因于二次硝酸铵和低δ 13 C比值，表明二次有机气溶胶。因子1和因子3分别增加了0.89和1.08 μgC m−3，夏季和秋季的贡献最大。因子2保留共振一致，并归因于花粉颗粒。其对WSOC的贡献从冬季的0.22 μ gCm −3到春季的1.04 μ gCm −3不等。
The functional and 13C isotopic compositions of water-soluble organic carbon (WSOC) in atmospheric aerosol were determined by nuclear magnetic resonance (1H-NMR) and isotope ratio mass spectrometry (IRMS) in an urban location in the Southern Mississippi Valley. The origin of WSOC was resolved using the functional distribution of organic hydrogen, δ13C ratio, and positive matrix factorization (PMF). Three factors were retained based on NMR spectral bins loadings. Two factors (factors 1 and 3) demonstrated strong associations with the aliphatic region in the NMR spectra and levoglucosan resonances. Differences between the two factors included the abundance of the aromatic functional group for factor 1, indicating fresh emissions and, for factor 3, the presence of resonances attributed to secondary ammonium nitrate and low δ13C ratio values that are indicative of secondary organic aerosol. Factors 1 and 3 added 0.89 and 1.08 μgC m−3, respectively, with the highest contribution in the summer and fall. Factor 2 retained resonances consistent with saccharides and was attributed to pollen particles. Its contribution to WSOC varied from 0.22 μgC m−3 in winter to 1.04 μgC m−3 in spring.