Diurnal variation in the water-soluble inorganic ions, organic carbon and isotopic compositions of total carbon and nitrogen in biomass burning aerosols from the LBA-SMOCC campaign in Rondonia, Brazil
Diurnal variation in the water-soluble inorganic ions, organic carbon and isotopic compositions of total carbon and nitrogen in biomass burning aerosols from the LBA-SMOCC campaign in Rondonia, Brazil
复制标题
DOI：
10.1016/j.jaerosci.2009.08.006
复制
发表时间：
2010-01-01
影响因子：
4.5
通讯作者：
Andreae, Meinrat O.
中科院分区：
文献类型：
--
作者：
Kundu, Shuvashish;Kawamura, Kimitaka;Andreae, Meinrat O.
2002年9月16日至26日，在巴西Rondonia的一个热带牧场，在生物质密集燃烧期间（n = 6）白天和夜间（n = 9）收集了气溶胶颗粒（PM2.5）。白天SO42-和CH3SO3-较高的标准化（通过K+、左旋葡萄糖糖或表观元素碳，ECa）质量浓度表明它们的光化学产物，而NO3-的相反趋势表明其在较低温度和较高湿度下转移到气溶胶相，以及可能通过水解N2O5在水溶液气溶胶颗粒上产生。利用GC-MS和GC-FID可以在分子水平上表征约4.2-7.5%的有机碳（5-13%的水溶性有机碳）。在检测到的有机化合物类别中，无水糖和芳烃的丰度在夜间样品中较高，而糖/糖醇、二酸、氧酸和α -二羰基的丰度在白天样品中较高。连续的白天和夜间样品表明，总碳（TC）的δ C-13值在白天样品中较低，这可以解释为由于主要是火焰燃烧，C-13中消耗的难熔TC贡献较大。总氮(TN) δ N-15值在+23.5 ~ +25.7‰之间，但昼夜样品无变化趋势。生物质燃烧颗粒的δ C-13和δ N-15值高于未燃烧植被的δ C-13和δ N-15值，反映了在颗粒形成过程中或颗粒向大气排放后的正同位素富集。2009爱思唯尔有限公司版权所有。
Aerosol particles (PM2.5) were collected during the day (n = 6) and nighttime (n = 9) from a tropical pasture site in Rondonia, Brazil during an intensive biomass burning period (16-26 September, 2002). Higher normalized (by K+, levoglucosan, or apparent elemental carbon, ECa) mass concentrations of SO42- and CH3SO3- in daytime suggest their photochemical production, while the opposite trend for NO3- suggests its transfer to the aerosol phase at lower temperatures and higher humidities, as well as possibly production through hydrolysis of N2O5 on aqueous aerosol particles. About 4.2-7.5% of OC (5-13% of water-soluble organic carbon (WSOC)) could be characterized at the molecular level using GC-MS and GC-FID. Among the detected organic compound classes, abundances of anhydrosugars and aromatics were higher in night samples, but sugars/sugar alcohols, diacids, oxoacids and alpha-dicarbonyls were more abundant in day samples. Consecutive day and night samples showed that delta C-13 values of total carbon (TC) were lower in daytime samples, which can be interpreted as resulting from higher contributions of refractory TC depleted in C-13 due to predominantly flaming combustion. The delta N-15 values of total nitrogen (TN) ranged from +23.5 parts per thousand to +25.7 parts per thousand, however, there was no trend in day and night samples. Higher values of delta C-13 and delta N-15 for biomass burning particles than those of unburned vegetation reflect positive isotopic enrichment either during the formation of particles or after the emission of particles in the atmosphere. (C) 2009 Elsevier Ltd. All rights reserved.