重庆白市驿PM2.5中糖类特征及来源
- Characteristics and Sources of Saccharides in PM2.5 in Baishiyi over Chongqing, China
- 基金项目：国家自然科学青年科学(No.42007188)；四川省自然科学(No.2022NSFSC1000)；成都信息工程大学,引进人才科研启动经费 (No. KYTZ202133);成都信息工程大学，校级大学生创新创业训练计划项目(No.202310621380)
- 徐成华
- 成都信息工程大学资源环境学院；大气环境模拟与污染控制四川省高校重点实验室，成都平原城市气象与环境四川省野外科学观测研究站
- 任红
- 成都信息工程大学资源环境学院；大气环境模拟与污染控制四川省高校重点实验室，成都平原城市气象与环境四川省野外科学观测研究站
- 摘要：大气有机颗粒物是引起大气污染的重要成分之一,而四川盆地典型山地城市大气PM2.5的有机组成及其特征研究较少。为探究盆地城市大气PM2.5中糖类化合物的特征,利用气相色谱-质谱联用(GC-MS)检测了重庆市白市驿不同季节PM2.5昼夜样品中的12种糖类化合物的浓度水平,包括脱水糖、初级糖和糖醇。糖类化合物的特征存在明显的昼夜变化和季节变化。研究结果表明：(1) 重庆市大气PM2.5中脱水糖占比超过85%,其中左旋葡聚糖占比最大。(2) 总糖浓度为(264±208) ng.m-3,白天(226±198) ng.m-3低于晚上(307±212) ng.m-3,主要由脱水糖的昼夜差异引起。(3) 总糖浓度呈现季节差异夏季(52.5±47.9 ng.m-3) < 秋季(287±172 ng.m-3) < 春季(294±206 ng.m-3) < 冬季(420±176 ng.m-3),受到气象条件、民用取暖、植被生长等多因素的影响。(4) 分子标志物源解析结果表明,生物质燃烧(BB-OC)、植物碎屑(P-OC)和真菌孢子(F-OC)排放的有机碳(Organic Carbon, OC)浓度分别为2166±1711 ngC.m-3、11.7±11.8 ngC.m-3和47.5±36.9 ngC.m-3,其对的OC的贡献分别为16.9 %、0.09 %和0.53 %。
- Abstract：Atmospheric organic particulate matter is one of the important components of air pollution, but there are few studies on the organic compositions and characteristics of PM2.5 in typical mountain city over Sichuan Basin. In order to investigate the characteristics of saccharide compounds of PM2.5 in urban areas of the Sichuan basin, daily and night samples of PM2.5 were collected in Baishiyi, Chongqing from July 2021 to April 2022. The concentrations of 12 saccharides were detected by gas chromatography-mass spectrometry (GC-MS), including anhydrosugars, primary sugars, and sugar alcohols. The results showed that: (1) anhydrosugar accounted for more than 85% was the main component in PM2.5, among which levoglucosan contributed the largest. (2) The total saccharide concentration was (264±208 ng.m-3), which showed lower concentration in the daytime (226±198 ng.m-3) than that of 307±212 ng.m-3 at night, mainly caused by the diurnal difference of anhydrosugars. (3) The total saccharide concentration showed seasonal differences in summer (52.5±47.9 ng.m-3) < autumn (287±172 ng.m-3) < spring (294±206 ng.m-3) < winter (420±176 ng.m-3), which might be related to factors such as meteorological conditions, domestic heating and vegetation growth. (4) The results of apportionment analysis by molecular marker showed that the contribution of organic carbon (OC) from biomass burning (BB-OC), plant debris (P-OC) and fungal spores (F-OC) was 2166±1711 ngC.m-3, 11.7±11.8 ngC.m-3 and 47.5±36.9 ngC.m-3, respectively, which accounted for 16.9%, 0.09% and 0.53% of OC, respectively.
