北京及周边6个城市大气PM2.5中左旋葡聚糖及其异构体的时空分布特征  

Spatial and Temporal Distribution Characteristics of Levoglucosan and Its Isomers in PM2.5 in Beijing and Six Surrounding Cities

作　　者：朱红霞[1] 陶雪梅 王超[1] 张霖琳[1] 郑晓燕[1] ZHU Hong-xia;TAO Xue-mei;WANG Chao;ZHANG Lin-lin;ZHENG Xiao-yan(China National Environmental Monitoring Centre,Beijing 100012,China;Gansu Province Environmental Monitoring Centre,Lanzhou 730030,China)

机构地区：[1]中国环境监测总站,北京100012 [2]甘肃省环境监测中心站,兰州730030

出　　处：《环境科学》2020年第4期1544-1549,共6页Environmental Science

基　　金：国家重点研发计划项目(2016YFC0208500,2016YFF0103000)。

摘　　要：采集北京及周边6个城市春、夏、秋、冬这4个季节大气PM2.5样品,用离子色谱法测定其中的左旋葡聚糖(LG)、甘露聚糖(MN)和半乳聚糖(GT),对比这3种脱水聚糖与PM2.5及有机碳(OC)的浓度水平和时空分布特征,应用SPSS 24.0软件分析了数据间的显著性差异.结果表明, 6个城市PM2.5、OC和LG浓度水平的季节分布规律高度相似,呈现冬季>春季>秋季>夏季, 4个季节3种脱水聚糖的浓度水平有显著性差异.从空间角度分析3种脱水聚糖浓度水平,北京与天津、保定、石家庄无显著性差异,但北京与济南、郑州有显著性差异.根据6个城市的LG/MN和LG/(MN+GT)等浓度水平的比较,初步判断该区域PM2.5中的生物质燃烧源主要来源于农作物秸秆和硬木.春季的PM2.5污染过程中,北京、天津、石家庄和济南的左旋葡聚糖在PM2.5中的含量变化基本保持稳定,显示该污染过程受生物质燃烧排放的影响较弱.Air PM2.5 samples from Beijing and six surrounding cities were collected during spring, summer, autumn, and winter. Levoglucosan(LG), mannosan(MN), and galactosan(GT) contents were analyzed by ion chromatography. The concentrations and distribution characteristics of the three anhydroglucoses with PM2.5 and organic carbon(OC) were compared. SPSS 24.0 was used to analyze the significant differences. The results indicated that the seasonal distributions of PM2.5, OC, and LG in the six cities were highly similar and followed the order winter>spring>autumn>summer. There were significant differences in the concentration levels of the three anhydroglucoses in the four seasons. Between Beijing and Tianjin, Baoding, and Shijiazhuang, there was no significant difference in the three anhydroglucose concentrations. However, significant differences in the three anhydroglucose concentrations appeared between Beijing, Ji’nan, and Zhengzhou. Based on the ratios of LG/MN and LG/(MN+GT) measured in the six cities, it could be determined that the biomass combustion sources in PM2.5 mainly came from crop straw and hardwood in this region. During the air pollution process in spring, LG stably existed in PM2.5 in Beijing, Tianjin, Shijiazhuang, and Ji’nan, indicating that this pollution process was weakly affected by biomass combustion.

关 键 词：左旋葡聚糖(LG) 甘露聚糖(MN) 半乳聚糖(GT) PM2.5 有机碳(OC) 时空分布 北京及周边6个城市 

分 类 号：X513[环境科学与工程—环境工程]