Wang Gehui, Kawamura Kimitaka, Hatakeyama Shiro, Takami Akinori, Li Hong, Wang Wei
Institute of Low Temperature Science, Hokkaido University, Kita 19, Nishi 8, Kita-ku, Sapporo 060-0819, Japan.
Environ Sci Technol. 2007 May 1;41(9):3115-20. doi: 10.1021/es062601h.
Lower to middle (0.5-3.0 km altitude) tropospheric aerosols (PM2.5) collected by aircraft over inland and east coastal China were, for the first time, characterized for organic molecular compositions to understand anthropogenic, natural, and photochemical contribution to the air quality. n-Alkanes, fatty acids, sugars, polyacids are detected as major compound classes, whereas lignin and resin products, sterols, polycyclic aromatic hydrocarbons, and phthalic acids are minor species. Average concentrations of all the identified compounds excluding malic acid correspond to 40-50% of those reported on the ground sites. Relative abundances of secondary organic aerosol (SOA) components such as malic acid are much higher in the aircraft samples, suggesting an enhanced photochemical production over China. Organic carbon (OC) concentrations in summer (average, 24.3 microg m(-3)) were equivalent to those reported on the ground sites. Higher OC/EC (elemental carbon) ratios in the summer aircraft samples also support a significant production of SOA over China. High loadings of organic aerosols in the Chinese troposphere may be responsible to an intercontinental transport of the pollutants and potential impact on the regional and global climate changes.
首次对在中国内陆和东部沿海地区上空通过飞机采集的低至中层（海拔0.5 - 3.0千米）对流层气溶胶（PM2.5）的有机分子组成进行了表征，以了解人为、自然和光化学过程对空气质量的贡献。正构烷烃、脂肪酸、糖类、多元酸被检测为主要化合物类别，而木质素和树脂产物、甾醇、多环芳烃和邻苯二甲酸则为次要成分。除苹果酸外，所有已鉴定化合物的平均浓度相当于地面站点报告浓度的40 - 50%。飞机样本中苹果酸等二次有机气溶胶（SOA）成分的相对丰度要高得多，这表明中国上空光化学生成增强。夏季有机碳（OC）浓度（平均为24.3微克/立方米）与地面站点报告的浓度相当。夏季飞机样本中较高的OC/EC（元素碳）比值也支持中国上空存在显著的SOA生成。中国对流层中高含量的有机气溶胶可能是污染物洲际传输的原因，并对区域和全球气候变化产生潜在影响。
