School of Studies in Chemistry, Pt. Ravishankar Shukla University, Raipur, Chhattisgarh, 492010, India.
School of Studies in Chemistry, Pt. Ravishankar Shukla University, Raipur, Chhattisgarh, 492010, India.
Environ Res. 2021 Apr;195:110802. doi: 10.1016/j.envres.2021.110802. Epub 2021 Jan 28.
Samples of ambient aerosols were collected at an urban site of eastern central India from monsoon to summer 2016-17 for the characterization of biogenic secondary organic aerosols (BSOA). The BSOA tracers derived from isoprene, α/β-pinene and β-caryophyllene in size-distributed aerosols were studied. Concentrations of total SOAI (Isoprene secondary organic aerosols) were found more abundant than α/β-pinene in summer, while contradictory trends were found in the winter season, where SOAM (monoterpene derived SOA) and SOAS (sesquiterpenes derived SOA) were dominated. Size-distribution study revealed that most of the BSOA were formed in the aerosol phase and dominated in fine mode, except cis-pinonic acid. They were formed in the gaseous phase and partitioned onto the aerosol phase. The alkaline nature of mineral dust particles that triggered the adsorption of gaseous species onto pre-existing particles could be the reason for bimodal size distribution with major coarse mode peak and miner fine mode peak. Temporal variations suggest that the BSOA must be derived from terrestrial vegetation and biomass burning. The isoprene SOC (secondary organic carbon) contributed 0.91%, 1.38%, 0.88% and 1.04% to OC during winter, summer, post-monsoon and monsoon season, respectively. The isoprene SOC in fine mode was found to be higher than the coarse mode.
本研究于 2016-17 年季风季至夏季在印度中东部的城市地区采集环境气溶胶样本，旨在分析其生物成因的二次有机气溶胶（BSOA）特性。通过对大气气溶胶中异戊二烯、α/β-蒎烯和β-石竹烯等 BSOA 示踪物的研究，发现总 SOAI（异戊二烯二次有机气溶胶）浓度在夏季比α/β-蒎烯更为丰富，而在冬季则呈现相反的趋势，此时 SOAM（单萜烯衍生的 SOA）和 SOAS（倍半萜烯衍生的 SOA）则占据主导地位。粒径分布研究表明，大部分 BSOA 是在气溶胶相中形成的，并以细模态为主，除顺式-戊烯二酸外。它们是在气相中形成的，并分配到气溶胶相中。矿物粉尘颗粒的碱性性质可能导致了双峰粒径分布，主要的粗模态峰和细模态峰，这触发了气态物质向预存在颗粒上的吸附。时间变化表明，BSOA 必须源自陆地植被和生物质燃烧。在冬季、夏季、季风后期和季风期，异戊二烯 SOC（二次有机碳）分别占 OC 的 0.91%、1.38%、0.88%和 1.04%。在细模态中，异戊二烯 SOC 高于粗模态。
