气候变化领域集成服务门户(CCPortal): Highly time-resolved chemical speciation and source apportionment of organic aerosol components in Delhi, India, using extractive electrospray ionization mass spectrometry

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DOI	10.5194/acp-22-7739-2022
	Highly time-resolved chemical speciation and source apportionment of organic aerosol components in Delhi, India, using extractive electrospray ionization mass spectrometry
	Kumar, Varun; Giannoukos, Stamatios; Haslett, Sophie L.; Tong, Yandong; Singh, Atinderpal; Bertrand, Amelie; Lee, Chuan Ping; Wang, Dongyu S.; Bhattu, Deepika; Stefenelli, Giulia; Dave, Jay S.; Puthussery, Joseph V.; Qi, Lu; Vats, Pawan; Rai, Pragati; Casotto, Roberto; Satish, Rangu; Mishra, Suneeti; Pospisilova, Veronika; Mohr, Claudia; Bell, David M.; Ganguly, Dilip; Verma, Vishal; Rastogi, Neeraj; Baltensperger, Urs; Tripathi, Sachchida N.; Prevot, Andre S. H.; Slowik, Jay G.
发表日期	2022
ISSN	1680-7316
EISSN	1680-7324
起始页码	7739
结束页码	7761
卷号	22 期号:11 页码:23
英文摘要	In recent years, the Indian capital city of Delhi has been impacted by very high levels of air pollution, especially during winter. Comprehensive knowledge of the composition and sources of the organic aerosol (OA), which constitutes a substantial fraction of total particulate mass (PM) in Delhi, is central to formulating effective public health policies. Previous source apportionment studies in Delhi identified key sources of primary OA (POA) and showed that secondary OA (SOA) played a major role but were unable to resolve specific SOA sources. We address the latter through the first field deployment of an extractive electrospray ionization timeof-flight mass spectrometer (EESI-TOF) in Delhi, together with a high-resolution aerosol mass spectrometer (AMS). Measurements were conducted during the winter of 2018/19, and positive matrix factorization (PMF) was used separately on AMS and EESI-TOF datasets to apportion the sources of OA. AMS PMF analysis yielded three primary and two secondary factors which were attributed to hydrocarbon-like OA (HOA), biomass burning OA (BBOA-1 and BBOA-2), more oxidized oxygenated OA (M0-00A), and less oxidized oxygenated OA (LO-OOA). On average, 40 % of the total OA mass was apportioned to the secondary factors. The SOA contribution to total OA mass varied greatly between the daytime (76.8 %, 10:00-16:00 local time (LT)) and nighttime (31.0 %, 21:00-04:00 LT). The higher chemical resolution of EESI-TOF data allowed identification of individual SOA sources. The EESI-TOF PMF analysis in total yielded six factors, two of which were primary factors (primary biomass burning and cooking-related OA). The remaining four factors were predominantly of secondary origin: aromatic SOA, biogenic SOA, aged biomass burning SOA, and mixed urban SOA. Due to the uncertainties in the EESI-TOF ion sensitivities, mass concentrations of EESI-TOF SOA-dominated factors were related to the total AMS SOA (i.e. MO-00A + LO-00A) by multiple linear regression (MLR). Aromatic SOA was the major SOA component during the daytime, with a 55.2 % contribution to total SOA mass (42.4 % contribution to total OA). Its contribution to total SOA, however, decreased to 25.4 % (7.9 % of total OA) during the nighttime. This factor was attributed to the oxidation of light aromatic compounds emitted mostly from traffic. Biogenic SOA accounted for 18.4 % of total SOA mass (14.2 % of total OA) during the daytime and 36.1 % of total SOA mass (11.2 % of total OA) during the nighttime. Aged biomass burning and mixed urban SOA accounted for 15.2 % and 11.0 % of total SOA mass (11.7 % and 8.5 % of total OA mass), respectively, during the daytime and 15.4 % and 22.9 % of total SOA mass (4.8 % and 7.1 % of total OA mass), respectively, during the nighttime. A simple dilution-partitioning model was applied on all EESI-TOF factors to estimate the fraction of observed daytime concentrations resulting from local photochemical production (SOA) or emissions (POA). Aromatic SOA, aged biomass burning, and mixed urban SOA were all found to be dominated by local photochemical production, likely from the oxidation of locally emitted volatile organic compounds (VOCs). In contrast, biogenic SOA was related to the oxidation of diffuse regional emissions of isoprene and monoterpenes. The findings of this study show that in Delhi, the nighttime high concentrations are caused by POA emissions led by traffic and biomass burning and the daytime OA is dominated by SOA, with aromatic SOA accounting for the largest fraction. Because aromatic SOA is possibly more toxic than biogenic SOA and primary OA, its dominance during the daytime suggests an increased OA toxicity and health-related consequences for the general public.
学科领域	Environmental Sciences; Meteorology & Atmospheric Sciences
语种	英语
WOS研究方向	Environmental Sciences & Ecology ; Meteorology & Atmospheric Sciences
WOS记录号	WOS:000811027600001
来源期刊	ATMOSPHERIC CHEMISTRY AND PHYSICS
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/273926
作者单位	Swiss Federal Institutes of Technology Domain; Paul Scherrer Institute; Stockholm University; Department of Space (DoS), Government of India; Physical Research Laboratory - India; University of Illinois System; University of Illinois Urbana-Champaign; Indian Institute of Technology System (IIT System); Indian Institute of Technology (IIT) - Delhi; Indian Institute of Technology System (IIT System); Indian Institute of Technology (IIT) - Kanpur; Indian Institute of Technology System (IIT System); Indian Institute of Technology (IIT) - Kanpur; Swiss Federal Institutes of Technology Domain; ETH Zurich; University of Delhi; Indian Institute of Technology System (IIT System); Indian Institute of Technology (IIT) - Jodhpur; TOFWERK AG
推荐引用方式 GB/T 7714	Kumar, Varun,Giannoukos, Stamatios,Haslett, Sophie L.,et al. Highly time-resolved chemical speciation and source apportionment of organic aerosol components in Delhi, India, using extractive electrospray ionization mass spectrometry[J],2022,22(11):23.
APA	Kumar, Varun.,Giannoukos, Stamatios.,Haslett, Sophie L..,Tong, Yandong.,Singh, Atinderpal.,...&Slowik, Jay G..(2022).Highly time-resolved chemical speciation and source apportionment of organic aerosol components in Delhi, India, using extractive electrospray ionization mass spectrometry.ATMOSPHERIC CHEMISTRY AND PHYSICS,22(11),23.
MLA	Kumar, Varun,et al."Highly time-resolved chemical speciation and source apportionment of organic aerosol components in Delhi, India, using extractive electrospray ionization mass spectrometry".ATMOSPHERIC CHEMISTRY AND PHYSICS 22.11(2022):23.