1
|
Yuan D, Qi Y, Ma C, Fu P, Volmer DA. Selective molecular characterization of organic aerosols using in situ laser desorption ionization mass spectrometry. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2024; 38:e9847. [PMID: 38890224 DOI: 10.1002/rcm.9847] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/20/2024] [Revised: 05/26/2024] [Accepted: 05/27/2024] [Indexed: 06/20/2024]
Abstract
RATIONALE The sources and chemical compositions of organic aerosol (OA) exert a significant influence on both regional and global atmospheric conditions, thereby having far-reaching implications on environmental chemistry. However, existing mass spectrometry (MS) methods have limitations in characterizing the detailed composition of OA due to selective ionization as well as fractionation during cold-water extraction and solid-phase extraction (SPE). METHODS A comprehensive MS study was conducted using aerosol samples collected on dusty, clean, and polluted days. To supplement the data obtained from electrospray ionization (ESI), a strategy for analyzing OAs collected using the quartz fiber filter directly utilizing laser desorption ionization (LDI) was employed. Additionally, the ESI method was conducted to explore suitable approaches for determining various OA compositions from samples collected on dusty, clean, and polluted days. RESULTS In situ LDI has the advantages of significantly reducing the sample volume, simplifying sample preparation, and overcoming the problem of overestimating sulfur-containing compounds usually encountered in ESI. It is suitable for the characterization of highly unsaturated and hydrophobic aerosols, such as brown carbon-type compounds with low volatility and high stability, which is supplementary to ESI. CONCLUSIONS Compared with other ionization methods, in situ LDI helps provide a complementary description of the molecular compositions of OAs, especially for analyzing OAs in polluted day samples. This method may contribute to a more comprehensive MS analysis of the elusive compositions and sources of OA in the atmosphere.
Collapse
Affiliation(s)
- Daohe Yuan
- Institute of Surface-Earth System Science, School of Earth System Science, Tianjin University, Tianjin, China
| | - Yulin Qi
- Institute of Surface-Earth System Science, School of Earth System Science, Tianjin University, Tianjin, China
- Tianjin Bohai Rim Coastal Earth Critical Zone National Observation and Research Station, Tianjin University, Tianjin, China
- Haihe Laboratory of Sustainable Chemical Transformations, Tianjin, China
| | - Chao Ma
- Institute of Surface-Earth System Science, School of Earth System Science, Tianjin University, Tianjin, China
| | - Pingqing Fu
- Institute of Surface-Earth System Science, School of Earth System Science, Tianjin University, Tianjin, China
- Tianjin Bohai Rim Coastal Earth Critical Zone National Observation and Research Station, Tianjin University, Tianjin, China
- Haihe Laboratory of Sustainable Chemical Transformations, Tianjin, China
| | - Dietrich A Volmer
- Bioanalytical Chemistry, Department of Chemistry, Humboldt University Berlin, Berlin, Germany
| |
Collapse
|
2
|
Li Z, Xiao H, Walters WW, Hastings MG, Min J, Song L, Lu W, Wu L, Yan W, Liu S, Fang Y. Nitrogen isotopic characteristics of aerosol ammonium in a Chinese megacity indicate the reduction from vehicle emissions during the lockdown period. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 922:171265. [PMID: 38417516 DOI: 10.1016/j.scitotenv.2024.171265] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2023] [Revised: 02/01/2024] [Accepted: 02/23/2024] [Indexed: 03/01/2024]
Abstract
The role of agricultural versus vehicle emissions in urban atmospheric ammonia (NH3) remains unclear. The lockdown due to the outbreak of COVID-19 provided an opportunity to assess the role of source emissions on urban NH3. Concentrations and δ15N of aerosol ammonium (NH4+) were measured before (autumn in 2017) and during the lockdown (summer, autumn, and winter in 2020), and source contributions were quantified using SIAR. Despite the insignificant decrease in NH4+ concentrations, significantly lower δ15N-NH4+ was found in 2020 (0.6 ± 1.0‰ in PM2.5 and 1.4 ± 2.1‰ in PM10) than in 2017 (15.2 ± 6.7‰ in PM2.5), which indicates the NH3 from vehicle emissions has decreased by∼50% during the lockdown while other source emissions are less affected. Moreover, a reversed seasonal pattern of δ15N-NH4+ during the lockdown in Changsha has been revealed compared to previous urban studies, which can be explained by the dominant effect of non-fossil fuel emissions due to the reductions of vehicle emissions during the lockdown period. Our results highlight the effects of lockdown on aerosol δ15N-NH4+ and the importance of vehicle emissions to urban atmospheric NH3, providing conclusive evidence that reducing vehicle NH3 emissions could be an effective strategy to reduce PM2.5 in Chinese megacities.
Collapse
Affiliation(s)
- Zhengjie Li
- National Engineering Laboratory for Applied Technology of Forestry & Ecology in Southern China, College of Biological Science and Technology, Central South University of Forestry and Technology, Changsha, Hunan 410004, China
| | - Hongwei Xiao
- School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Wendell W Walters
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, SC 29208, USA
| | - Meredith G Hastings
- Institute at Brown for Environment and Society, Department of Earth, Environmental and Planetary Sciences, Brown University, Providence, RI 02912, USA
| | - Juan Min
- National Engineering Laboratory for Applied Technology of Forestry & Ecology in Southern China, College of Biological Science and Technology, Central South University of Forestry and Technology, Changsha, Hunan 410004, China
| | - Linlin Song
- CAS Key Laboratory of Forest Ecology and Management, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, Liaoning 110016, China; Key Laboratory of Stable Isotope Techniques and Applications, Liaoning Province 110016, China
| | - Weizhi Lu
- National Engineering Laboratory for Applied Technology of Forestry & Ecology in Southern China, College of Biological Science and Technology, Central South University of Forestry and Technology, Changsha, Hunan 410004, China
| | - Libin Wu
- Institute of Surface-Earth System Science, School of Earth System Science, Tianjin University, Tianjin 300072, China
| | - Wende Yan
- National Engineering Laboratory for Applied Technology of Forestry & Ecology in Southern China, College of Biological Science and Technology, Central South University of Forestry and Technology, Changsha, Hunan 410004, China
| | - Shuguang Liu
- National Engineering Laboratory for Applied Technology of Forestry & Ecology in Southern China, College of Biological Science and Technology, Central South University of Forestry and Technology, Changsha, Hunan 410004, China.
| | - Yunting Fang
- CAS Key Laboratory of Forest Ecology and Management, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, Liaoning 110016, China; Key Laboratory of Stable Isotope Techniques and Applications, Liaoning Province 110016, China; Qingyuan Forest CERN, Chinese Academy of Sciences, Shenyang, Liaoning 110016, China.
| |
Collapse
|
3
|
Feng S, Li M, Wang K, Liu X, Xu W. Source apportionment of atmospheric ammonia in suburban Beijing revealed through 15N-stable isotopes. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 920:170728. [PMID: 38325487 DOI: 10.1016/j.scitotenv.2024.170728] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/18/2023] [Revised: 01/29/2024] [Accepted: 02/03/2024] [Indexed: 02/09/2024]
Abstract
Addressing the urgent issue of atmospheric ammonia (NH3) emissions is crucial in combating poor air quality in megacities. Previous research has highlighted the significant contribution of nonagricultural sources, particularly fossil fuel emissions, to urban NH3 levels. However, there is limited assessment of NH3 dynamics in suburban areas. This study focuses on four suburban sites in Beijing, covering a 16 to 22-month observation period, to investigate spatial and temporal patterns of NH3 concentrations. The δ15N-stable isotope method is employed to identify NH3 sources and their contributions. Our results demonstrate that agricultural sources (53 %) dominate atmospheric NH3 emissions in suburban areas of Beijing, surpassing nonagricultural sources, and primarily emanate from local sources. Notably, fertilizer application (37 ± 11 %) and livestock breeding (32 ± 6 %) emerge as the primary contributors in summer and spring, respectively, leading to significantly elevated NH3 concentrations during these seasons. Even in autumn and winter, both agricultural (49 %) and nonagricultural (51 %) sources contribute almost equally to NH3 emissions. This study emphasizes the need for coordinated efforts to control atmospheric NH3 pollution in Beijing City, with particular attention to addressing both vehicular and agricultural emissions.
Collapse
Affiliation(s)
- Sijie Feng
- State Key Laboratory of Nutrient Use and Management, College of Resources and Environmental Sciences, National Academy of Agriculture Green Development, National Observation and Research Station of Agriculture Green Development (Quzhou, Hebei), China Agricultural University, Beijing 100193, China
| | - Meitong Li
- State Key Laboratory of Nutrient Use and Management, College of Resources and Environmental Sciences, National Academy of Agriculture Green Development, National Observation and Research Station of Agriculture Green Development (Quzhou, Hebei), China Agricultural University, Beijing 100193, China
| | - Kaiyan Wang
- State Key Laboratory of Nutrient Use and Management, College of Resources and Environmental Sciences, National Academy of Agriculture Green Development, National Observation and Research Station of Agriculture Green Development (Quzhou, Hebei), China Agricultural University, Beijing 100193, China
| | - Xuejun Liu
- State Key Laboratory of Nutrient Use and Management, College of Resources and Environmental Sciences, National Academy of Agriculture Green Development, National Observation and Research Station of Agriculture Green Development (Quzhou, Hebei), China Agricultural University, Beijing 100193, China
| | - Wen Xu
- State Key Laboratory of Nutrient Use and Management, College of Resources and Environmental Sciences, National Academy of Agriculture Green Development, National Observation and Research Station of Agriculture Green Development (Quzhou, Hebei), China Agricultural University, Beijing 100193, China.
| |
Collapse
|