Molecular signatures and formation mechanisms of water-soluble chromophores in particulate matter from Karachi in Pakistan

doi:10.1016/j.scitotenv.2024.169890

	Molecular signatures and formation mechanisms of water-soluble chromophores in particulate matter from Karachi in Pakistan
	Tang, Jiao 1,2; Li, Jun 1,2; Zhao, Shizhen 1,2; Zhong, Guangcai 1,2; Mo, Yangzhi 1,2; Jiang, Hongxing 3; Jiang, Bin 1,2; Chen, Yingjun 3; Tang, Jianhui 4; Tian, Chongguo 4
刊名	SCIENCE OF THE TOTAL ENVIRONMENT
	2024-03-01
卷号	914 页码:12
关键词	Brown carbon Fluorescence spectroscopy Molecular composition Formation pathways
ISSN号	0048-9697
DOI	10.1016/j.scitotenv.2024.169890
通讯作者	Li, Jun(junli@gig.ac.cn) ; Zhang, Gan(zhanggan@gig.ac.cn)
英文摘要	Excitation -emission matrix (EEM) fluorescence spectroscopy is a widely -used method for characterizing the chemical components of brown carbon (BrC). However, the molecular basics and formation mechanisms of chromophores, which are decomposed by parallel factor (PARAFAC) analysis, are not yet fully understood. In this study, we characterized the water-soluble organic carbon (WSOC) in aerosols collected from Karachi, Pakistan, using EEM spectroscopy and Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS). We identified three PARAFAC components, including two humic-like components (C1 and C2) and one phenolic -like species (C3). We determined the molecular families associated with each component by performing Spearman correlation analysis between FT-ICR MS peaks and PARAFAC component intensities. We found that the C1 and C2 components were associated with nitrogen -enriched compounds, where C2 with the longest emission wavelength exhibited a higher level of aromaticity, N content, and oxygenation than C1. The C3 associated formulas have fewer nitrogen -containing species, a lower unsaturation degree, and a lower oxidation state. An oxidation pathway was identified as an important process in the formation of C1 and C2 components at the molecular level, particularly for the assigned CHON compounds associated with the gas -phase oxidation process, despite their diverse precursor types. Numerous C2 formulas were found in the "potential BrC" region and overlapped with the BrC-associated formulas. It can be inferred that the compounds that fluoresce C2 contributed considerably to the light absorption of BrC. These findings are essential for future studies utilizing the EEM-PARAFAC method to explore the sources, processes, and compositions of atmospheric BrC.
WOS关键词	DISSOLVED ORGANIC-MATTER ; LIGHT-ABSORPTION CHARACTERISTICS ; BROWN CARBON ; OPTICAL-PROPERTIES ; MASS-SPECTROMETRY ; SEASONAL SNOW ; AEROSOLS ; FLUORESCENCE ; IDENTIFICATION ; REGION
WOS研究方向	Environmental Sciences & Ecology
语种	英语
WOS记录号	WOS:001163575100001
资助机构	National Natural Science Foundation of China ; Alliance of International Science Organizations ; Guangdong Basic and Applied Basic Research Foundation ; Youth Innovation Promotion Association, CAS
内容类型	期刊论文
源URL	[http://ir.yic.ac.cn/handle/133337/34875]
专题	中国科学院烟台海岸带研究所
通讯作者	Li, Jun; Zhang, Gan
作者单位	1.Chinese Acad Sci, State Key Lab Organ Geochem, Guangzhou 510640, Peoples R China 2.Chinese Acad Sci, Guangzhou Inst Geochem, Guangdong Prov Key Lab Environm Protect & Resource, Guangdong Hong Kong Macao Joint Lab Environm Pollu, Hong Kong 510640, Guangdong, Peoples R China 3.Fudan Univ, Dept Environm Sci & Engn, Shanghai Key Lab Atmospher Particle Pollut & Preve, Shanghai 200433, Peoples R China 4.Chinese Acad Sci, Yantai Inst Coastal Zone Res, Key Lab Coastal Environm Proc & Ecol Remediat, Yantai 264003, Peoples R China 5.Shandong Univ, Environm Res Inst, Qingdao 266237, Peoples R China 6.COMSATS Univ Islamabad CUI, Dept Meteorol, Islamabad 45550, Pakistan
推荐引用方式 GB/T 7714	Tang, Jiao,Li, Jun,Zhao, Shizhen,et al. Molecular signatures and formation mechanisms of water-soluble chromophores in particulate matter from Karachi in Pakistan[J]. SCIENCE OF THE TOTAL ENVIRONMENT,2024,914:12.
APA	Tang, Jiao.,Li, Jun.,Zhao, Shizhen.,Zhong, Guangcai.,Mo, Yangzhi.,...&Zhang, Gan.(2024).Molecular signatures and formation mechanisms of water-soluble chromophores in particulate matter from Karachi in Pakistan.SCIENCE OF THE TOTAL ENVIRONMENT,914,12.
MLA	Tang, Jiao,et al."Molecular signatures and formation mechanisms of water-soluble chromophores in particulate matter from Karachi in Pakistan".SCIENCE OF THE TOTAL ENVIRONMENT 914(2024):12.