Articles | Volume 3, issue 2
https://doi.org/10.5194/ar-3-619-2025
© Author(s) 2025. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
https://doi.org/10.5194/ar-3-619-2025
© Author(s) 2025. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Research article
| 
08 Dec 2025
Research article |
| 08 Dec 2025
| 08 Dec 2025
The evolution of carbon oxidation state during secondary organic aerosol formation from individual and mixed organic precursors
Yunqi Shao
School of Earth and Environmental Science, University of Manchester, Manchester, M13 9PL, UK
Aristeidis Voliotis
School of Earth and Environmental Science, University of Manchester, Manchester, M13 9PL, UK
National Centre for Atmospheric Science (NCAS), University of Manchester, Manchester, M13 9PL, UK
School of Earth and Environmental Science, University of Manchester, Manchester, M13 9PL, UK
now at: School of Geography Earth and Environment Sciences, University of Birmingham, Birmingham, B15 2TT, UK
School of Earth and Environmental Science, University of Manchester, Manchester, M13 9PL, UK
now at: School of Geosciences, University of Edinburgh, Edinburgh, EH9 3FF, UK
Thomas J. Bannan
School of Earth and Environmental Science, University of Manchester, Manchester, M13 9PL, UK
Jacqueline F. Hamilton
Wolfson Atmospheric Chemistry Laboratories, Department of Chemistry, University of York, York, YO105DD, UK
M. Rami Alfarra
School of Earth and Environmental Science, University of Manchester, Manchester, M13 9PL, UK
National Centre for Atmospheric Science (NCAS), University of Manchester, Manchester, M13 9PL, UK
now at: Qatar Environment and Energy Research Institute, Hamad Bin Khalifa University, Doha, Qatar
Gordon McFiggans
CORRESPONDING AUTHOR
School of Earth and Environmental Science, University of Manchester, Manchester, M13 9PL, UK
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Ensuring the atmospheric relevance of experimental conditions is crucial for advancing understanding of secondary organic aerosols (SOA). We investigated the impact of CO, a common trace gas, on SOA particle mass yields and composition from biogenic and anthropogenic precursors and their mixture in the presence of NOx. The results show different CO effects between single- and mixed-precursor systems, highlighting the need to capture atmospheric complexity in laboratory studies.
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Mixing experiments are crucial and highly beneficial for our understanding of atmospheric chemical interactions. However, interpretation quickly becomes complex, and both the experimental design and evaluation need to be scrutinised carefully. Advanced online and offline compositional measurements can reveal substantial additional information to aid in the interpretation of yield data, including components uniquely found in mixtures and property changes in SOA formed from mixtures of VOCs.
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Atmospheric chemistry plays a key role in the understanding of aerosol formation and air pollution. We designed chamber experiments for the characterization of secondary organic aerosol (SOA) from a biogenic precursor with inorganic seed. Our results highlight the advantages of a combination of online FIGAERO-CIMS and offline LC-Orbitrap MS analytical techniques to characterize the chemical composition of SOA in chamber studies.
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Here, we developed new techniques for investigating these properties in the laboratory and applied these to BC and BrC from different sources, including diesel exhaust, inverted propane flame and wood combustion. These have allowed us to quantify the changes in shape and chemical composition of different soots according to source and variables such as the moisture content of wood.
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Yarê Baker, Sungah Kang, Hui Wang, Rongrong Wu, Jian Xu, Annika Zanders, Quanfu He, Thorsten Hohaus, Till Ziehm, Veronica Geretti, Thomas J. Bannan, Simon P. O'Meara, Aristeidis Voliotis, Mattias Hallquist, Gordon McFiggans, Sören R. Zorn, Andreas Wahner, and Thomas F. Mentel
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Joanna E. Dyson, Lisa K. Whalley, Eloise J. Slater, Robert Woodward-Massey, Chunxiang Ye, James D. Lee, Freya Squires, James R. Hopkins, Rachel E. Dunmore, Marvin Shaw, Jacqueline F. Hamilton, Alastair C. Lewis, Stephen D. Worrall, Asan Bacak, Archit Mehra, Thomas J. Bannan, Hugh Coe, Carl J. Percival, Bin Ouyang, C. Nicholas Hewitt, Roderic L. Jones, Leigh R. Crilley, Louisa J. Kramer, W. Joe F. Acton, William J. Bloss, Supattarachai Saksakulkrai, Jingsha Xu, Zongbo Shi, Roy M. Harrison, Simone Kotthaus, Sue Grimmond, Yele Sun, Weiqi Xu, Siyao Yue, Lianfang Wei, Pingqing Fu, Xinming Wang, Stephen R. Arnold, and Dwayne E. Heard
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Daniel J. Bryant, Beth S. Nelson, Stefan J. Swift, Sri Hapsari Budisulistiorini, Will S. Drysdale, Adam R. Vaughan, Mike J. Newland, James R. Hopkins, James M. Cash, Ben Langford, Eiko Nemitz, W. Joe F. Acton, C. Nicholas Hewitt, Tuhin Mandal, Bhola R. Gurjar, Shivani, Ranu Gadi, James D. Lee, Andrew R. Rickard, and Jacqueline F. Hamilton
Atmos. Chem. Phys., 23, 61–83, https://doi.org/10.5194/acp-23-61-2023, https://doi.org/10.5194/acp-23-61-2023, 2023
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Alfred W. Mayhew, Ben H. Lee, Joel A. Thornton, Thomas J. Bannan, James Brean, James R. Hopkins, James D. Lee, Beth S. Nelson, Carl Percival, Andrew R. Rickard, Marvin D. Shaw, Peter M. Edwards, and Jaqueline F. Hamilton
Atmos. Chem. Phys., 22, 14783–14798, https://doi.org/10.5194/acp-22-14783-2022, https://doi.org/10.5194/acp-22-14783-2022, 2022
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Isoprene nitrates are chemical species commonly found in the atmosphere that are important for their impacts on air quality and climate. This paper compares 3 different representations of the chemistry of isoprene nitrates in computational models highlighting cases where the choice of chemistry included has significant impacts on the concentration and composition of the modelled nitrates. Calibration of mass spectrometers is also shown to be an important factor when analysing isoprene nitrates.
Aristeidis Voliotis, Mao Du, Yu Wang, Yunqi Shao, M. Rami Alfarra, Thomas J. Bannan, Dawei Hu, Kelly L. Pereira, Jaqueline F. Hamilton, Mattias Hallquist, Thomas F. Mentel, and Gordon McFiggans
Atmos. Chem. Phys., 22, 14147–14175, https://doi.org/10.5194/acp-22-14147-2022, https://doi.org/10.5194/acp-22-14147-2022, 2022
Short summary
Short summary
Mixing experiments are crucial and highly beneficial for our understanding of atmospheric chemical interactions. However, interpretation quickly becomes complex, and both the experimental design and evaluation need to be scrutinised carefully. Advanced online and offline compositional measurements can reveal substantial additional information to aid in the interpretation of yield data, including components uniquely found in mixtures and property changes in SOA formed from mixtures of VOCs.
Aristeidis Voliotis, Mao Du, Yu Wang, Yunqi Shao, Thomas J. Bannan, Michael Flynn, Spyros N. Pandis, Carl J. Percival, M. Rami Alfarra, and Gordon McFiggans
Atmos. Chem. Phys., 22, 13677–13693, https://doi.org/10.5194/acp-22-13677-2022, https://doi.org/10.5194/acp-22-13677-2022, 2022
Short summary
Short summary
The addition of a low-yield precursor to the reactive mixture of aVOC and bVOC can increase or decrease the SOA volatility that is system-dependent. Therefore, the SOA volatility of the mixtures cannot always be predicted based on the additivity. In complex mixtures the formation of lower-volatility products likely outweighs the formation of products with higher volatility. The unique products of each mixture contribute significantly to the signal, suggesting interactions can be important.
Ruiqi Man, Zhijun Wu, Taomou Zong, Aristeidis Voliotis, Yanting Qiu, Johannes Größ, Dominik van Pinxteren, Limin Zeng, Hartmut Herrmann, Alfred Wiedensohler, and Min Hu
Atmos. Chem. Phys., 22, 12387–12399, https://doi.org/10.5194/acp-22-12387-2022, https://doi.org/10.5194/acp-22-12387-2022, 2022
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Regional and total deposition doses for different age groups were quantified based on explicit hygroscopicity measurements. We found that particle hygroscopic growth led to a reduction (~24 %) in the total dose. The deposition rate of hygroscopic particles was higher in the daytime, while hydrophobic particles exhibited a higher rate at night and during rush hours. The results will deepen the understanding of the impact of hygroscopicity and the mixing state on deposition patterns in the lungs.
Yunqi Shao, Aristeidis Voliotis, Mao Du, Yu Wang, Kelly Pereira, Jacqueline Hamilton, M. Rami Alfarra, and Gordon McFiggans
Atmos. Chem. Phys., 22, 9799–9826, https://doi.org/10.5194/acp-22-9799-2022, https://doi.org/10.5194/acp-22-9799-2022, 2022
Short summary
Short summary
This study explored the chemical properties of secondary organic aerosol (SOA) that formed from photo-oxidation of single and mixed biogenic and anthropogenic precursors. We showed that SOA chemical properties in a mixed vapour system are mainly affected by the
higher-yield precursor's oxidation products and products from
cross-product formation. This study also identifies potential tracer compounds in a mixed vapour system that might be used in SOA source attribution in future ambient studies.
Mao Du, Aristeidis Voliotis, Yunqi Shao, Yu Wang, Thomas J. Bannan, Kelly L. Pereira, Jacqueline F. Hamilton, Carl J. Percival, M. Rami Alfarra, and Gordon McFiggans
Atmos. Meas. Tech., 15, 4385–4406, https://doi.org/10.5194/amt-15-4385-2022, https://doi.org/10.5194/amt-15-4385-2022, 2022
Short summary
Short summary
Atmospheric chemistry plays a key role in the understanding of aerosol formation and air pollution. We designed chamber experiments for the characterization of secondary organic aerosol (SOA) from a biogenic precursor with inorganic seed. Our results highlight the advantages of a combination of online FIGAERO-CIMS and offline LC-Orbitrap MS analytical techniques to characterize the chemical composition of SOA in chamber studies.
Sebastian Diez, Stuart E. Lacy, Thomas J. Bannan, Michael Flynn, Tom Gardiner, David Harrison, Nicholas Marsden, Nicholas A. Martin, Katie Read, and Pete M. Edwards
Atmos. Meas. Tech., 15, 4091–4105, https://doi.org/10.5194/amt-15-4091-2022, https://doi.org/10.5194/amt-15-4091-2022, 2022
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Regardless of the cost of the measuring instrument, there are no perfect measurements. For this reason, we compare the quality of the information provided by cheap devices when they are used to measure air pollutants and we try to emphasise that before judging the potential usefulness of the devices, the user must specify his own needs. Since commonly used performance indices/metrics can be misleading in qualifying this, we propose complementary visual analysis to the more commonly used metrics.
Yu Wang, Aristeidis Voliotis, Dawei Hu, Yunqi Shao, Mao Du, Ying Chen, Judith Kleinheins, Claudia Marcolli, M. Rami Alfarra, and Gordon McFiggans
Atmos. Chem. Phys., 22, 4149–4166, https://doi.org/10.5194/acp-22-4149-2022, https://doi.org/10.5194/acp-22-4149-2022, 2022
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Aerosol water uptake plays a key role in atmospheric physicochemical processes. We designed chamber experiments on aerosol water uptake of secondary organic aerosol (SOA) from mixed biogenic and anthropogenic precursors with inorganic seed. Our results highlight this chemical composition influences the reconciliation of the sub- and super-saturated water uptake, providing laboratory evidence for understanding the chemical controls of water uptake of the multi-component aerosol.
Jessica Slater, Hugh Coe, Gordon McFiggans, Juha Tonttila, and Sami Romakkaniemi
Atmos. Chem. Phys., 22, 2937–2953, https://doi.org/10.5194/acp-22-2937-2022, https://doi.org/10.5194/acp-22-2937-2022, 2022
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This paper shows the specific impact of black carbon (BC) on the aerosol–planetary boundary layer (PBL) feedback and its influence on a Beijing haze episode. Overall, this paper shows that strong temperature inversions prevent BC heating within the PBL from significantly increasing PBL height, while BC above the PBL suppresses PBL development significantly through the day. From this we suggest a method by which both locally and regionally emitted BC may impact urban pollution episodes.
Yunqi Shao, Yu Wang, Mao Du, Aristeidis Voliotis, M. Rami Alfarra, Simon P. O'Meara, S. Fiona Turner, and Gordon McFiggans
Atmos. Meas. Tech., 15, 539–559, https://doi.org/10.5194/amt-15-539-2022, https://doi.org/10.5194/amt-15-539-2022, 2022
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A comprehensive description and characterisation of the Manchester Aerosol Chamber (MAC) was conducted. The MAC has good temperature and relative humidity homogeneity, fast mixing times, and comparable losses of gases and particles with other chambers. The MAC's bespoke control system allows improved duty cycles and repeatable experiments. Moreover, the effect of contamination on performance was also investigated. It is highly recommended to regularly track the chamber's performance.
Dawei Hu, M. Rami Alfarra, Kate Szpek, Justin M. Langridge, Michael I. Cotterell, Claire Belcher, Ian Rule, Zixia Liu, Chenjie Yu, Yunqi Shao, Aristeidis Voliotis, Mao Du, Brett Smith, Greg Smallwood, Prem Lobo, Dantong Liu, Jim M. Haywood, Hugh Coe, and James D. Allan
Atmos. Chem. Phys., 21, 16161–16182, https://doi.org/10.5194/acp-21-16161-2021, https://doi.org/10.5194/acp-21-16161-2021, 2021
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Here, we developed new techniques for investigating these properties in the laboratory and applied these to BC and BrC from different sources, including diesel exhaust, inverted propane flame and wood combustion. These have allowed us to quantify the changes in shape and chemical composition of different soots according to source and variables such as the moisture content of wood.
Aristeidis Voliotis, Yu Wang, Yunqi Shao, Mao Du, Thomas J. Bannan, Carl J. Percival, Spyros N. Pandis, M. Rami Alfarra, and Gordon McFiggans
Atmos. Chem. Phys., 21, 14251–14273, https://doi.org/10.5194/acp-21-14251-2021, https://doi.org/10.5194/acp-21-14251-2021, 2021
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Secondary organic aerosol (SOA) formation from mixtures of volatile precursors can be affected by the molecular interactions of the products. Composition and volatility measurements of SOA formed from mixtures of anthropogenic and biogenic precursors reveal processes that can increase or decrease the SOA volatility. The unique products of the mixture were more oxygenated and less volatile than those from either precursor. Analytical context is provided to explore the SOA volatility in mixtures.
Xuan Wang, Daniel J. Jacob, William Downs, Shuting Zhai, Lei Zhu, Viral Shah, Christopher D. Holmes, Tomás Sherwen, Becky Alexander, Mathew J. Evans, Sebastian D. Eastham, J. Andrew Neuman, Patrick R. Veres, Theodore K. Koenig, Rainer Volkamer, L. Gregory Huey, Thomas J. Bannan, Carl J. Percival, Ben H. Lee, and Joel A. Thornton
Atmos. Chem. Phys., 21, 13973–13996, https://doi.org/10.5194/acp-21-13973-2021, https://doi.org/10.5194/acp-21-13973-2021, 2021
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Halogen radicals have a broad range of implications for tropospheric chemistry, air quality, and climate. We present a new mechanistic description and comprehensive simulation of tropospheric halogens in a global 3-D model and compare the model results with surface and aircraft measurements. We find that halogen chemistry decreases the global tropospheric burden of ozone by 11 %, NOx by 6 %, and OH by 4 %.
Beth S. Nelson, Gareth J. Stewart, Will S. Drysdale, Mike J. Newland, Adam R. Vaughan, Rachel E. Dunmore, Pete M. Edwards, Alastair C. Lewis, Jacqueline F. Hamilton, W. Joe Acton, C. Nicholas Hewitt, Leigh R. Crilley, Mohammed S. Alam, Ülkü A. Şahin, David C. S. Beddows, William J. Bloss, Eloise Slater, Lisa K. Whalley, Dwayne E. Heard, James M. Cash, Ben Langford, Eiko Nemitz, Roberto Sommariva, Sam Cox, Shivani, Ranu Gadi, Bhola R. Gurjar, James R. Hopkins, Andrew R. Rickard, and James D. Lee
Atmos. Chem. Phys., 21, 13609–13630, https://doi.org/10.5194/acp-21-13609-2021, https://doi.org/10.5194/acp-21-13609-2021, 2021
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Ozone production at an urban site in Delhi is sensitive to volatile organic compound (VOC) concentrations, particularly those of the aromatic, monoterpene, and alkene VOC classes. The change in ozone production by varying atmospheric pollutants according to their sources, as defined in an emissions inventory, is investigated. The study suggests that reducing road transport emissions alone does not reduce reactive VOCs in the atmosphere enough to perturb an increase in ozone production.
James Weber, Scott Archer-Nicholls, Nathan Luke Abraham, Youngsub M. Shin, Thomas J. Bannan, Carl J. Percival, Asan Bacak, Paulo Artaxo, Michael Jenkin, M. Anwar H. Khan, Dudley E. Shallcross, Rebecca H. Schwantes, Jonathan Williams, and Alex T. Archibald
Geosci. Model Dev., 14, 5239–5268, https://doi.org/10.5194/gmd-14-5239-2021, https://doi.org/10.5194/gmd-14-5239-2021, 2021
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The new mechanism CRI-Strat 2 features state-of-the-art isoprene chemistry not previously available in UKCA and improves UKCA's ability to reproduce observed concentrations of isoprene, monoterpenes, and OH in tropical regions. The enhanced ability to model isoprene, the most widely emitted non-methane volatile organic compound (VOC), will allow understanding of how isoprene and other biogenic VOCs affect atmospheric composition and, through biosphere–atmosphere feedbacks, climate change.
Ernesto Reyes-Villegas, Upasana Panda, Eoghan Darbyshire, James M. Cash, Rutambhara Joshi, Ben Langford, Chiara F. Di Marco, Neil J. Mullinger, Mohammed S. Alam, Leigh R. Crilley, Daniel J. Rooney, W. Joe F. Acton, Will Drysdale, Eiko Nemitz, Michael Flynn, Aristeidis Voliotis, Gordon McFiggans, Hugh Coe, James Lee, C. Nicholas Hewitt, Mathew R. Heal, Sachin S. Gunthe, Tuhin K. Mandal, Bhola R. Gurjar, Shivani, Ranu Gadi, Siddhartha Singh, Vijay Soni, and James D. Allan
Atmos. Chem. Phys., 21, 11655–11667, https://doi.org/10.5194/acp-21-11655-2021, https://doi.org/10.5194/acp-21-11655-2021, 2021
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This paper shows the first multisite online measurements of PM1 in Delhi, India, with measurements over different seasons in Old Delhi and New Delhi in 2018. Organic aerosol (OA) source apportionment was performed using positive matrix factorisation (PMF). Traffic was the main primary aerosol source for both OAs and black carbon, seen with PMF and Aethalometer model analysis, indicating that control of primary traffic exhaust emissions would make a significant reduction to Delhi air pollution.
Yu Wang, Aristeidis Voliotis, Yunqi Shao, Taomou Zong, Xiangxinyue Meng, Mao Du, Dawei Hu, Ying Chen, Zhijun Wu, M. Rami Alfarra, and Gordon McFiggans
Atmos. Chem. Phys., 21, 11303–11316, https://doi.org/10.5194/acp-21-11303-2021, https://doi.org/10.5194/acp-21-11303-2021, 2021
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Aerosol phase behaviour plays a profound role in atmospheric physicochemical processes. We designed dedicated chamber experiments to study the phase state of secondary organic aerosol from biogenic and anthropogenic mixed precursors. Our results highlight the key role of the organic–inorganic ratio and relative humidity in phase state, but the sources and organic composition are less important. The result provides solid laboratory evidence for understanding aerosol phase in a complex atmosphere.
Benjamin A. Nault, Duseong S. Jo, Brian C. McDonald, Pedro Campuzano-Jost, Douglas A. Day, Weiwei Hu, Jason C. Schroder, James Allan, Donald R. Blake, Manjula R. Canagaratna, Hugh Coe, Matthew M. Coggon, Peter F. DeCarlo, Glenn S. Diskin, Rachel Dunmore, Frank Flocke, Alan Fried, Jessica B. Gilman, Georgios Gkatzelis, Jacqui F. Hamilton, Thomas F. Hanisco, Patrick L. Hayes, Daven K. Henze, Alma Hodzic, James Hopkins, Min Hu, L. Greggory Huey, B. Thomas Jobson, William C. Kuster, Alastair Lewis, Meng Li, Jin Liao, M. Omar Nawaz, Ilana B. Pollack, Jeffrey Peischl, Bernhard Rappenglück, Claire E. Reeves, Dirk Richter, James M. Roberts, Thomas B. Ryerson, Min Shao, Jacob M. Sommers, James Walega, Carsten Warneke, Petter Weibring, Glenn M. Wolfe, Dominique E. Young, Bin Yuan, Qiang Zhang, Joost A. de Gouw, and Jose L. Jimenez
Atmos. Chem. Phys., 21, 11201–11224, https://doi.org/10.5194/acp-21-11201-2021, https://doi.org/10.5194/acp-21-11201-2021, 2021
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Secondary organic aerosol (SOA) is an important aspect of poor air quality for urban regions around the world, where a large fraction of the population lives. However, there is still large uncertainty in predicting SOA in urban regions. Here, we used data from 11 urban campaigns and show that the variability in SOA production in these regions is predictable and is explained by key emissions. These results are used to estimate the premature mortality associated with SOA in urban regions.
Michael Priestley, Thomas J. Bannan, Michael Le Breton, Stephen D. Worrall, Sungah Kang, Iida Pullinen, Sebastian Schmitt, Ralf Tillmann, Einhard Kleist, Defeng Zhao, Jürgen Wildt, Olga Garmash, Archit Mehra, Asan Bacak, Dudley E. Shallcross, Astrid Kiendler-Scharr, Åsa M. Hallquist, Mikael Ehn, Hugh Coe, Carl J. Percival, Mattias Hallquist, Thomas F. Mentel, and Gordon McFiggans
Atmos. Chem. Phys., 21, 3473–3490, https://doi.org/10.5194/acp-21-3473-2021, https://doi.org/10.5194/acp-21-3473-2021, 2021
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A significant fraction of emissions from human activity consists of aromatic hydrocarbons, e.g. benzene, which oxidise to form new compounds important for particle growth. Characterisation of benzene oxidation products highlights the range of species produced as well as their chemical properties and contextualises them within relevant frameworks, e.g. MCM. Cluster analysis of the oxidation product time series distinguishes behaviours of CHON compounds that could aid in identifying functionality.
Gareth J. Stewart, Beth S. Nelson, W. Joe F. Acton, Adam R. Vaughan, Naomi J. Farren, James R. Hopkins, Martyn W. Ward, Stefan J. Swift, Rahul Arya, Arnab Mondal, Ritu Jangirh, Sakshi Ahlawat, Lokesh Yadav, Sudhir K. Sharma, Siti S. M. Yunus, C. Nicholas Hewitt, Eiko Nemitz, Neil Mullinger, Ranu Gadi, Lokesh K. Sahu, Nidhi Tripathi, Andrew R. Rickard, James D. Lee, Tuhin K. Mandal, and Jacqueline F. Hamilton
Atmos. Chem. Phys., 21, 2407–2426, https://doi.org/10.5194/acp-21-2407-2021, https://doi.org/10.5194/acp-21-2407-2021, 2021
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Biomass burning releases many lower-molecular-weight organic species which are difficult to analyse but important for the formation of organic aerosol. This study examined a new high-resolution technique to better characterise these difficult-to-analyse organic components. Some burning sources analysed in this study, such as cow dung cake and municipal solid waste, released extremely complex mixtures containing many thousands of different lower-volatility organic compounds.
Gareth J. Stewart, W. Joe F. Acton, Beth S. Nelson, Adam R. Vaughan, James R. Hopkins, Rahul Arya, Arnab Mondal, Ritu Jangirh, Sakshi Ahlawat, Lokesh Yadav, Sudhir K. Sharma, Rachel E. Dunmore, Siti S. M. Yunus, C. Nicholas Hewitt, Eiko Nemitz, Neil Mullinger, Ranu Gadi, Lokesh K. Sahu, Nidhi Tripathi, Andrew R. Rickard, James D. Lee, Tuhin K. Mandal, and Jacqueline F. Hamilton
Atmos. Chem. Phys., 21, 2383–2406, https://doi.org/10.5194/acp-21-2383-2021, https://doi.org/10.5194/acp-21-2383-2021, 2021
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Biomass burning is a major source of trace gases to the troposphere; however, the composition and quantity of emissions vary greatly between different fuel types. This work provided near-total quantitation of non-methane volatile organic compounds from combustion of biofuels from India. Emissions from cow dung cake combustion were significantly larger than conventional fuelwood combustion, potentially indicating that this source has a disproportionately large impact on regional air quality.
Lisa K. Whalley, Eloise J. Slater, Robert Woodward-Massey, Chunxiang Ye, James D. Lee, Freya Squires, James R. Hopkins, Rachel E. Dunmore, Marvin Shaw, Jacqueline F. Hamilton, Alastair C. Lewis, Archit Mehra, Stephen D. Worrall, Asan Bacak, Thomas J. Bannan, Hugh Coe, Carl J. Percival, Bin Ouyang, Roderic L. Jones, Leigh R. Crilley, Louisa J. Kramer, William J. Bloss, Tuan Vu, Simone Kotthaus, Sue Grimmond, Yele Sun, Weiqi Xu, Siyao Yue, Lujie Ren, W. Joe F. Acton, C. Nicholas Hewitt, Xinming Wang, Pingqing Fu, and Dwayne E. Heard
Atmos. Chem. Phys., 21, 2125–2147, https://doi.org/10.5194/acp-21-2125-2021, https://doi.org/10.5194/acp-21-2125-2021, 2021
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To understand how emission controls will impact ozone, an understanding of the sources and sinks of OH and the chemical cycling between peroxy radicals is needed. This paper presents measurements of OH, HO2 and total RO2 taken in central Beijing. The radical observations are compared to a detailed chemistry model, which shows that under low NO conditions, there is a missing OH source. Under high NOx conditions, the model under-predicts RO2 and impacts our ability to model ozone.
Mike J. Newland, Daniel J. Bryant, Rachel E. Dunmore, Thomas J. Bannan, W. Joe F. Acton, Ben Langford, James R. Hopkins, Freya A. Squires, William Dixon, William S. Drysdale, Peter D. Ivatt, Mathew J. Evans, Peter M. Edwards, Lisa K. Whalley, Dwayne E. Heard, Eloise J. Slater, Robert Woodward-Massey, Chunxiang Ye, Archit Mehra, Stephen D. Worrall, Asan Bacak, Hugh Coe, Carl J. Percival, C. Nicholas Hewitt, James D. Lee, Tianqu Cui, Jason D. Surratt, Xinming Wang, Alastair C. Lewis, Andrew R. Rickard, and Jacqueline F. Hamilton
Atmos. Chem. Phys., 21, 1613–1625, https://doi.org/10.5194/acp-21-1613-2021, https://doi.org/10.5194/acp-21-1613-2021, 2021
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We report the formation of secondary pollutants in the urban megacity of Beijing that are typically associated with remote regions such as rainforests. This is caused by extremely low levels of nitric oxide (NO), typically expected to be high in urban areas, observed in the afternoon. This work has significant implications for how we understand atmospheric chemistry in the urban environment and thus for how to implement effective policies to improve urban air quality.
Simon Patrick O'Meara, Shuxuan Xu, David Topping, M. Rami Alfarra, Gerard Capes, Douglas Lowe, Yunqi Shao, and Gordon McFiggans
Geosci. Model Dev., 14, 675–702, https://doi.org/10.5194/gmd-14-675-2021, https://doi.org/10.5194/gmd-14-675-2021, 2021
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User-friendly and open-source software for simulating aerosol chambers is a valuable tool for research scientists in designing and analysing their experiments. This paper describes a new version of such software and will therefore provide a useful reference for those applying it. Central to the paper is an assessment of the software's accuracy through comparison against previously published simulations.
Patrick A. Barker, Grant Allen, Martin Gallagher, Joseph R. Pitt, Rebecca E. Fisher, Thomas Bannan, Euan G. Nisbet, Stéphane J.-B. Bauguitte, Dominika Pasternak, Samuel Cliff, Marina B. Schimpf, Archit Mehra, Keith N. Bower, James D. Lee, Hugh Coe, and Carl J. Percival
Atmos. Chem. Phys., 20, 15443–15459, https://doi.org/10.5194/acp-20-15443-2020, https://doi.org/10.5194/acp-20-15443-2020, 2020
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Africa is estimated to account for approximately 52 % of global biomass burning (BB) carbon emissions. Despite this, there has been little previous in situ study of African BB emissions. This work presents BB emission factors for various atmospheric trace gases sampled from an aircraft in two distinct areas of Africa (Senegal and Uganda). Intracontinental variability in biomass burning methane emission is identified, which is attributed to difference in the specific fuel mixtures burnt.
Cited articles
Ahlberg, E., Falk, J., Eriksson, A., Holst, T., Brune, W. H., Kristensson, A., Roldin, P., and Svenningsson, B.: Secondary organic aerosol from VOC mixtures in an oxidation flow reactor, Atmospheric Environment, 161, 210–220, https://doi.org/10.1016/j.atmosenv.2017.05.005, 2017.
Aiken, A. C., DeCarlo, P. F., Kroll, J. H., Worsnop, D. R., Huffman, J. A., Docherty, K. S., Ulbrich, I. M., Mohr, C., Kimmel, J. R., Sueper, D., Sun, Y., Zhang, Q., Trimborn, A., Northway, M., Ziemann, P. J., Canagaratna, M. R., Onasch, T. B., Alfarra, M. R., Prevot, A. S. H., Dommen, J., Duplissy, J., Metzger, A., Baltensperger, U., and Jimenez, J. L.: O
Alfarra, M. R., Coe, H., Allan, J. D., Bower, K. N., Boudries, H., Canagaratna, M. R., Jimenez, J. L., Jayne, J. T., Garforth, A. A., Li, S.-M., and Worsnop, D. R.: Characterization of urban and rural organic particulate in the Lower Fraser Valley using two Aerodyne Aerosol Mass Spectrometers, Atmospheric Environment, 38, 5745–5758, https://doi.org/10.1016/j.atmosenv.2004.01.054, 2004.
Atkinson, R., Baulch, D. L., Cox, R. A., Crowley, J. N., Hampson, R. F., Hynes, R. G., Jenkin, M. E., Rossi, M. J., and Troe, J.: Evaluated kinetic and photochemical data for atmospheric chemistry: Volume I - gas phase reactions of Ox, HOx, NOx and SOx species, Atmos. Chem. Phys., 4, 1461–1738, https://doi.org/10.5194/acp-4-1461-2004, 2004.
Bruns, E. A., Perraud, V., Zelenyuk, A., Ezell, M. J., Johnson, S. N., Yu, Y., Imre, D., Finlayson-Pitts, B. J., and Alexander, M. L.: Comparison of FTIR and Particle Mass Spectrometry for the Measurement of Particulate Organic Nitrates, Environmental Science & Technology, 44, 1056–1061, https://doi.org/10.1021/es9029864, 2010.
Carlton, A. G., Wiedinmyer, C., and Kroll, J. H.: A review of Secondary Organic Aerosol (SOA) formation from isoprene, Atmos. Chem. Phys., 9, 4987–5005, https://doi.org/10.5194/acp-9-4987-2009, 2009.
Chen, X., Li, K., Li, R., Fang, L., Bian, H., Jiang, W., Yan, C., and Du, L.: NOx-driven chemical transformation of terpene mixtures: Linking highly oxygenated organic molecules to health effects in secondary organic aerosol, Journal of Environmental Sciences, https://doi.org/10.1016/j.jes.2025.09.004, 2025.
Chhabra, P. S., Flagan, R. C., and Seinfeld, J. H.: Elemental analysis of chamber organic aerosol using an aerodyne high-resolution aerosol mass spectrometer, Atmos. Chem. Phys., 10, 4111–4131, https://doi.org/10.5194/acp-10-4111-2010, 2010.
Cui, Y., Chen, K., Zhang, H., Lin, Y.-H., and Bahreini, R.: Chemical Composition and Optical Properties of Secondary Organic Aerosol from Photooxidation of Volatile Organic Compound Mixtures, ACS ES&T Air, 1, 247–258, https://doi.org/10.1021/acsestair.3c00041, 2024.
D'Ambro, E. L., Schobesberger, S., Gaston, C. J., Lopez-Hilfiker, F. D., Lee, B. H., Liu, J., Zelenyuk, A., Bell, D., Cappa, C. D., Helgestad, T., Li, Z., Guenther, A., Wang, J., Wise, M., Caylor, R., Surratt, J. D., Riedel, T., Hyttinen, N., Salo, V.-T., Hasan, G., Kurtén, T., Shilling, J. E., and Thornton, J. A.: Chamber-based insights into the factors controlling epoxydiol (IEPOX) secondary organic aerosol (SOA) yield, composition, and volatility, Atmos. Chem. Phys., 19, 11253–11265, https://doi.org/10.5194/acp-19-11253-2019, 2019.
Daumit, K. E., Kessler, S. H., and Kroll, J. H.: Average chemical properties and potential formation pathways of highly oxidized organic aerosol, Faraday Discuss, 165, 181–202, https://doi.org/10.1039/c3fd00045a, 2013.
DeCarlo, P. F., Kimmel, J. R., Trimborn, A., Northway, M. J., Jayne, J. T., Aiken, A. C., Gonin, M., Fuhrer, K., Horvath, T., Docherty, K. S., Worsnop, D. R., and Jimenez, J. L.: Field-Deployable, High-Resolution, Time-of-Flight Aerosol Mass Spectrometer, Analytical Chemistry, 78, 8281–8289, https://doi.org/10.1021/ac061249n, 2006.
Dillon, T. J., Dulitz, K., Groß, C. B. M., and Crowley, J. N.: Temperature-dependent rate coefficients for the reactions of the hydroxyl radical with the atmospheric biogenics isoprene, alpha-pinene and delta-3-carene, Atmos. Chem. Phys., 17, 15137–15150, https://doi.org/10.5194/acp-17-15137-2017, 2017.
Docherty, K. S., Corse, E. W., Jaoui, M., Offenberg, J. H., Kleindienst, T. E., Krug, J. D., Riedel, T. P., and Lewandowski, M.: Trends in the oxidation and relative volatility of chamber-generated secondary organic aerosol, Aerosol Science and Technology, 52, 992–1004, https://doi.org/10.1080/02786826.2018.1500014, 2018.
Du, M., Voliotis, A., Shao, Y., Wang, Y., Bannan, T. J., Pereira, K. L., Hamilton, J. F., Percival, C. J., Alfarra, M. R., and McFiggans, G.: Combined application of online FIGAERO-CIMS and offline LC-Orbitrap mass spectrometry (MS) to characterize the chemical composition of secondary organic aerosol (SOA) in smog chamber studies, Atmos. Meas. Tech., 15, 4385–4406, https://doi.org/10.5194/amt-15-4385-2022, 2022.
Eddingsaas, N. C., Loza, C. L., Yee, L. D., Chan, M., Schilling, K. A., Chhabra, P. S., Seinfeld, J. H., and Wennberg, P. O.: α-pinene photooxidation under controlled chemical conditions – Part 2: SOA yield and composition in low- and high-NOx environments, Atmos. Chem. Phys., 12, 7413–7427, https://doi.org/10.5194/acp-12-7413-2012, 2012.
Fry, J. L., Kiendler-Scharr, A., Rollins, A. W., Wooldridge, P. J., Brown, S. S., Fuchs, H., Dubé, W., Mensah, A., dal Maso, M., Tillmann, R., Dorn, H.-P., Brauers, T., and Cohen, R. C.: Organic nitrate and secondary organic aerosol yield from NO3 oxidation of β-pinene evaluated using a gas-phase kinetics/aerosol partitioning model, Atmos. Chem. Phys., 9, 1431–1449, https://doi.org/10.5194/acp-9-1431-2009, 2009.
Han, S., Li, Z., Lau, Y. S., Xiao, Y., Miljevic, B., Horchler, J., Li, J., Hu, W.-P., Wang, H., Wang, B., and Ristovski, Z.: Unraveling secondary organic aerosol formation from isoprene and toluene mixture, npj Climate and Atmospheric Science, 8, 311, https://doi.org/10.1038/s41612-025-01189-4, 2025.
Hildebrandt, L., Henry, K. M., Kroll, J. H., Worsnop, D. R., Pandis, S. N., and Donahue, N. M.: Evaluating the Mixing of Organic Aerosol Components Using High-Resolution Aerosol Mass Spectrometry, Environmental Science & Technology, 45, 6329–6335, https://doi.org/10.1021/es200825g, 2011.
Hoffmann, T., Odum, J. R., Bowman, F., Collins, D., Klockow, D., Flagan, R. C., and Seinfeld, J. H.: Formation of Organic Aerosols from the Oxidation of Biogenic Hydrocarbons, Journal of Atmospheric Chemistry, 26, 189–222, https://doi.org/10.1023/A:1005734301837, 1997.
Hoffmann, T., Huang, R.-J., and Kalberer, M.: Atmospheric Analytical Chemistry, Analytical Chemistry, 83, 4649–4664, https://doi.org/10.1021/ac2010718, 2011.
Jayne, J. T., Leard, D. C., Zhang, X., Davidovits, P., Smith, K. A., Kolb, C. E., and Worsnop, D. R.: Development of an aerosol mass spectrometer for size and composition analysis of submicron particles, Aerosol Science & Technology, 33, 49–70, 2000.
Jimenez, J. L., Jayne, J. T., Shi, Q., Kolb, C. E., Worsnop, D. R., Yourshaw, I., Seinfeld, J. H., Flagan, R. C., Zhang, X., Smith, K. A., Morris, J. W., and Davidovits, P.: Ambient aerosol sampling using the Aerodyne Aerosol Mass Spectrometer, Journal of Geophysical Research: Atmospheres, 108, https://doi.org/10.1029/2001JD001213, 2003.
Kroll, J. H., Ng, N. L., Murphy, S. M., Flagan, R. C., and Seinfeld, J. H.: Secondary organic aerosol formation from isoprene photooxidation under high-NOx conditions, Geophysical Research Letters, 32, https://doi.org/10.1029/2005GL023637, 2005a.
Kroll, J. H., Ng, N. L., Murphy, S. M., Varutbangkul, V., Flagan, R. C., and Seinfeld, J. H.: Chamber studies of secondary organic aerosol growth by reactive uptake of simple carbonyl compounds, Journal of Geophysical Research: Atmospheres, 110, https://doi.org/10.1029/2005JD006004, 2005b.
Kroll, J. H., Donahue, N. M., Jimenez, J. L., Kessler, S. H., Canagaratna, M. R., Wilson, K. R., Altieri, K. E., Mazzoleni, L. R., Wozniak, A. S., Bluhm, H., Mysak, E. R., Smith, J. D., Kolb, C. E., and Worsnop, D. R.: Carbon oxidation state as a metric for describing the chemistry of atmospheric organic aerosol, Nature Chemistry, 3, 133–139, https://doi.org/10.1038/nchem.948, 2011.
Kroll, J. H., Lim, C. Y., Kessler, S. H., and Wilson, K. R.: Heterogeneous Oxidation of Atmospheric Organic Aerosol: Kinetics of Changes to the Amount and Oxidation State of Particle-Phase Organic Carbon, The Journal of Physical Chemistry A, 119, 10767–10783, https://doi.org/10.1021/acs.jpca.5b06946, 2015.
Lee, B.-H., Pierce, J. R., Engelhart, G. J., and Pandis, S. N.: Volatility of secondary organic aerosol from the ozonolysis of monoterpenes, Atmospheric Environment, 45, 2443–2452, https://doi.org/10.1016/j.atmosenv.2011.02.004, 2011.
Lee, B. H., Lopez-Hilfiker, F. D., Mohr, C., Kurtén, T., Worsnop, D. R., and Thornton, J. A.: An Iodide-Adduct High-Resolution Time-of-Flight Chemical-Ionization Mass Spectrometer: Application to Atmospheric Inorganic and Organic Compounds, Environmental Science & Technology, 48, 6309–6317, https://doi.org/10.1021/es500362a, 2014.
Li, K., Zhang, X., Zhao, B., Bloss, W. J., Lin, C., White, S., Yu, H., Chen, L., Geng, C., Yang, W., Azzi, M., George, C., and Bai, Z.: Suppression of anthropogenic secondary organic aerosol formation by isoprene, npj Climate and Atmospheric Science, 5, 12, https://doi.org/10.1038/s41612-022-00233-x, 2022.
Lopez-Hilfiker, F. D., Mohr, C., Ehn, M., Rubach, F., Kleist, E., Wildt, J., Mentel, Th. F., Lutz, A., Hallquist, M., Worsnop, D., and Thornton, J. A.: A novel method for online analysis of gas and particle composition: description and evaluation of a Filter Inlet for Gases and AEROsols (FIGAERO), Atmos. Meas. Tech., 7, 983–1001, https://doi.org/10.5194/amt-7-983-2014, 2014.
McFiggans, G., Mentel, T. F., Wildt, J., Pullinen, I., Kang, S., Kleist, E., Schmitt, S., Springer, M., Tillmann, R., and Wu, C.: Secondary organic aerosol reduced by mixture of atmospheric vapours, Nature, 565, 587, https://doi.org/10.1038/s41586-018-0871-y, 2019.
McFiggans, G.: Atmospheric simulation chamber study: alpha-pinene + ortho-cresol + isoprene + OH – Aerosol study – particle formation – 2019-07-19 (Version 1.0), AERIS [dataset], https://doi.org/10.25326/HNCK-KE85, 2020.
Pandis, S. N., Paulson, S. E., Seinfeld, J. H., and Flagan, R. C.: Aerosol formation in the photooxidation of isoprene and β-pinene, Atmospheric Environment. Part A. General Topics, 25, 997–1008, https://doi.org/10.1016/0960-1686(91)90141-S, 1991.
Pereira, K., Ward, M., Wilkinson, J., Sallach, J., Bryant, D., Dixon, W., Hamilton, J., and Lewis, A.: An Automated Methodology for Non-targeted Compositional Analysis of Small Molecules in High Complexity Environmental Matrices Using Coupled Ultra Performance Liquid Chromatography Orbitrap Mass Spectrometry, Environmental Science & Technology, https://doi.org/10.1021/acs.est.0c08208, 2021.
Presto, A. A., Miracolo, M. A., Kroll, J. H., Worsnop, D. R., Robinson, A. L., and Donahue, N. M.: Intermediate-Volatility Organic Compounds: A Potential Source of Ambient Oxidized Organic Aerosol, Environmental Science & Technology, 43, 4744–4749, https://doi.org/10.1021/es803219q, 2009.
Pullinen, I., Schmitt, S., Kang, S., Sarrafzadeh, M., Schlag, P., Andres, S., Kleist, E., Mentel, T. F., Rohrer, F., Springer, M., Tillmann, R., Wildt, J., Wu, C., Zhao, D., Wahner, A., and Kiendler-Scharr, A.: Impact of NOx on secondary organic aerosol (SOA) formation from α-pinene and β-pinene photooxidation: the role of highly oxygenated organic nitrates, Atmos. Chem. Phys., 20, 10125–10147, https://doi.org/10.5194/acp-20-10125-2020, 2020.
Shao, Y., Voliotis, A., Du, M., Wang, Y., Pereira, K., Hamilton, J., Alfarra, M. R., and McFiggans, G.: Chemical composition of secondary organic aerosol particles formed from mixtures of anthropogenic and biogenic precursors, Atmos. Chem. Phys., 22, 9799–9826, https://doi.org/10.5194/acp-22-9799-2022, 2022a.
Shao, Y., Wang, Y., Du, M., Voliotis, A., Alfarra, M. R., O'Meara, S. P., Turner, S. F., and McFiggans, G.: Characterisation of the Manchester Aerosol Chamber facility, Atmos. Meas. Tech., 15, 539–559, https://doi.org/10.5194/amt-15-539-2022, 2022b.
Shilling, J. E., Chen, Q., King, S. M., Rosenoern, T., Kroll, J. H., Worsnop, D. R., DeCarlo, P. F., Aiken, A. C., Sueper, D., Jimenez, J. L., and Martin, S. T.: Loading-dependent elemental composition of α-pinene SOA particles, Atmos. Chem. Phys., 9, 771–782, https://doi.org/10.5194/acp-9-771-2009, 2009.
Stark, H., Yatavelli, R. L. N., Thompson, S. L., Kimmel, J. R., Cubison, M. J., Chhabra, P. S., Canagaratna, M. R., Jayne, J. T., Worsnop, D. R., and Jimenez, J. L.: Methods to extract molecular and bulk chemical information from series of complex mass spectra with limited mass resolution, International Journal of Mass Spectrometry, 389, 26–38, https://doi.org/10.1016/j.ijms.2015.08.011, 2015.
Stroud, C. A., Roberts, J. M., Goldan, P. D., Kuster, W. C., Murphy, P. C., Williams, E. J., Hereid, D., Parrish, D., Sueper, D., Trainer, M., Fehsenfeld, F. C., Apel, E. C., Riemer, D., Wert, B., Henry, B., Fried, A., Martinez-Harder, M., Harder, H., Brune, W. H., Li, G., Xie, H., and Young, V. L.: Isoprene and its oxidation products, methacrolein and methylvinyl ketone, at an urban forested site during the 1999 Southern Oxidants Study, Journal of Geophysical Research: Atmospheres, 106, 8035–8046, https://doi.org/10.1029/2000JD900628, 2001.
Sueper, D. and collaborators: ToF-AMS Data Analysis Software, University of Colorado Boulder, http://cires1.colorado.edu/jimenez-group/wiki/index.php/ToF-AMS_Analysis_Software (last access: 3 December 2025), 2023.
Surratt, J. D., Kroll, J. H., Kleindienst, T. E., Edney, E. O., Claeys, M., Sorooshian, A., Ng, N. L., Offenberg, J. H., Lewandowski, M., Jaoui, M., Flagan, R. C., and Seinfeld, J. H.: Evidence for Organosulfates in Secondary Organic Aerosol, Environmental Science & Technology, 41, 517–527, https://doi.org/10.1021/es062081q, 2007.
Surratt, J. D., Gómez-González, Y., Chan, A. W. H., Vermeylen, R., Shahgholi, M., Kleindienst, T. E., Edney, E. O., Offenberg, J. H., Lewandowski, M., Jaoui, M., Maenhaut, W., Claeys, M., Flagan, R. C., and Seinfeld, J. H.: Organosulfate Formation in Biogenic Secondary Organic Aerosol, The Journal of Physical Chemistry A, 112, 8345–8378, https://doi.org/10.1021/jp802310p, 2008.
Voliotis, A., Wang, Y., Shao, Y., Du, M., Bannan, T. J., Percival, C. J., Pandis, S. N., Alfarra, M. R., and McFiggans, G.: Exploring the composition and volatility of secondary organic aerosols in mixed anthropogenic and biogenic precursor systems, Atmos. Chem. Phys., 21, 14251–14273, https://doi.org/10.5194/acp-21-14251-2021, 2021.
Voliotis, A., Du, M., Wang, Y., Shao, Y., Bannan, T. J., Flynn, M., Pandis, S. N., Percival, C. J., Alfarra, M. R., and McFiggans, G.: The influence of the addition of isoprene on the volatility of particles formed from the photo-oxidation of anthropogenic–biogenic mixtures, Atmos. Chem. Phys., 22, 13677–13693, https://doi.org/10.5194/acp-22-13677-2022, 2022a.
Voliotis, A., Du, M., Wang, Y., Shao, Y., Alfarra, M. R., Bannan, T. J., Hu, D., Pereira, K. L., Hamilton, J. F., Hallquist, M., Mentel, T. F., and McFiggans, G.: Chamber investigation of the formation and transformation of secondary organic aerosol in mixtures of biogenic and anthropogenic volatile organic compounds, Atmos. Chem. Phys., 22, 14147–14175, https://doi.org/10.5194/acp-22-14147-2022, 2022b.
Wennberg, P. O., Bates, K. H., Crounse, J. D., Dodson, L. G., McVay, R. C., Mertens, L. A., Nguyen, T. B., Praske, E., Schwantes, R. H., Smarte, M. D., St Clair, J. M., Teng, A. P., Zhang, X., and Seinfeld, J. H.: Gas-Phase Reactions of Isoprene and Its Major Oxidation Products, Chemical Reviews, 118, 3337–3390, https://doi.org/10.1021/acs.chemrev.7b00439, 2018.
Winterhalter, R., Van Dingenen, R., Larsen, B. R., Jensen, N. R., and Hjorth, J.: LC-MS analysis of aerosol particles from the oxidation of α-pinene by ozone and OH-radicals, Atmos. Chem. Phys. Discuss., 3, 1–39, https://doi.org/10.5194/acpd-3-1-2003, 2003.
Xu, L., Middlebrook, A. M., Liao, J., de Gouw, J. A., Guo, H., Weber, R. J., Nenes, A., Lopez-Hilfiker, F. D., Lee, B. H., Thornton, J. A., Brock, C. A., Neuman, J. A., Nowak, J. B., Pollack, I. B., Welti, A., Graus, M., Warneke, C., and Ng, N. L.: Enhanced formation of isoprene-derived organic aerosol in sulfur-rich power plant plumes during Southeast Nexus, Journal of Geophysical Research: Atmospheres, 121, 11137–11153, https://doi.org/10.1002/2016jd025156, 2016.
Zhao, Y., Zhao, Y., Wang, C., Shao, Y., Xie, H., Yang, J., Zhang, W., Wu, G., Li, G., Jiang, L., and Yang, X.: Photooxidation and ozonolysis of α-pinene and limonene mixtures: Mechanisms of secondary organic aerosol formation and cross-dimerization, Journal of Environmental Sciences, https://doi.org/10.1016/j.jes.2025.04.020, 2025.
Short summary
This study analysed the average carbon oxidation state (OSc) during secondary organic aerosol formation from mixed volatile organic compounds (VOCs) using three mass spectrometry techniques. Notable discrepancies in OSc were observed across the techniques, with FIGAERO-CIMS reporting higher values. The results also show that OSc in mixed-VOC systems is influenced not only by products from individual precursors but also by accretion products formed through interactions between VOC products.
This study analysed the average carbon oxidation state (OSc) during secondary organic aerosol...
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