1
|
Kenseth CM, Hafeman NJ, Rezgui SP, Chen J, Huang Y, Dalleska NF, Kjaergaard HG, Stoltz BM, Seinfeld JH, Wennberg PO. Particle-phase accretion forms dimer esters in pinene secondary organic aerosol. Science 2023; 382:787-792. [PMID: 37972156 DOI: 10.1126/science.adi0857] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2023] [Accepted: 10/11/2023] [Indexed: 11/19/2023]
Abstract
Secondary organic aerosol (SOA) is ubiquitous in the atmosphere and plays a pivotal role in climate, air quality, and health. The production of low-volatility dimeric compounds through accretion reactions is a key aspect of SOA formation. However, despite extensive study, the structures and thus the formation mechanisms of dimers in SOA remain largely uncharacterized. In this work, we elucidate the structures of several major dimer esters in SOA from ozonolysis of α-pinene and β-pinene-substantial global SOA sources-through independent synthesis of authentic standards. We show that these dimer esters are formed in the particle phase and propose a mechanism of nucleophilic addition of alcohols to a cyclic acylperoxyhemiacetal. This chemistry likely represents a general pathway to dimeric compounds in ambient SOA.
Collapse
Affiliation(s)
- Christopher M Kenseth
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA 91125, USA
| | - Nicholas J Hafeman
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA 91125, USA
| | - Samir P Rezgui
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA 91125, USA
| | - Jing Chen
- Department of Chemistry, University of Copenhagen, DK-2100 Copenhagen, Denmark
| | - Yuanlong Huang
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA 91125, USA
| | - Nathan F Dalleska
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA 91125, USA
| | - Henrik G Kjaergaard
- Department of Chemistry, University of Copenhagen, DK-2100 Copenhagen, Denmark
| | - Brian M Stoltz
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA 91125, USA
| | - John H Seinfeld
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA 91125, USA
- Division of Engineering and Applied Science, California Institute of Technology, Pasadena, CA 91125, USA
| | - Paul O Wennberg
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA 91125, USA
- Division of Engineering and Applied Science, California Institute of Technology, Pasadena, CA 91125, USA
| |
Collapse
|
2
|
Burdette TC, Bramblett RL, Zimmermann K, Frossard AA. Influence of Air Mass Source Regions on Signatures of Surface-Active Organic Molecules in Size Resolved Atmospheric Aerosol Particles. ACS EARTH & SPACE CHEMISTRY 2023; 7:1578-1591. [PMID: 37609122 PMCID: PMC10441572 DOI: 10.1021/acsearthspacechem.3c00161] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/09/2023] [Revised: 07/21/2023] [Accepted: 07/21/2023] [Indexed: 08/24/2023]
Abstract
The physical and chemical properties of atmospheric aerosol particles depend on their sources and lifetime in the atmosphere. In coastal regions, sources may include influences from marine, continental, anthropogenic, and natural emissions. In this study, particles in ten diameter-size ranges were collected, and particle number size distributions were measured, at Skidaway Island, GA in May and June 2018. Based on air mass back trajectories and concentrations of major ions in the particles, the air mass source regions were identified as Marine Influenced, Mixed, and Continental Influenced. Organic molecules were extracted from the particles using solid-phase extraction and characterized using tensiometry and high-resolution mass spectrometry. The presence of surfactants was confirmed in the extracts through the observation of significant surface tension depressions. The organic formulas contained high hydrogen-to-carbon (H/C) and low oxygen-to-carbon (O/C) ratios, similar to surfactants and lipid-like molecules. In the Marine Influenced particles, the fraction of formulas identified as surfactant-like was negatively correlated with minimum surface tensions; as the surfactant fraction increased, the surface tension decreased. Analyses of fatty acid compounds demonstrated that organic compounds extracted from the Marine Influenced particles had the highest carbon numbers (18), compared to those of the Mixed (15) and Continental Influenced (9) particles. This suggests that the fatty acids in the Continental Influenced particles may have been more aged in the atmosphere and undergone fragmentation. This is one of the first studies to measure the chemical and physical properties of surfactants in size-resolved particles from different air mass source regions.
Collapse
Affiliation(s)
- Tret C. Burdette
- Department
of Chemistry, University of Georgia, Athens, Georgia 30606, United States
| | - Rachel L. Bramblett
- Department
of Chemistry, University of Georgia, Athens, Georgia 30606, United States
| | - Kathryn Zimmermann
- Department
of Chemistry, Georgia Gwinnett College, Lawrenceville, Georgia 30043, United States
| | - Amanda A. Frossard
- Department
of Chemistry, University of Georgia, Athens, Georgia 30606, United States
| |
Collapse
|
3
|
Qi Y, Fu P, Volmer DA. Analysis of natural organic matter via fourier transform ion cyclotron resonance mass spectrometry: an overview of recent non-petroleum applications. MASS SPECTROMETRY REVIEWS 2022; 41:647-661. [PMID: 32412674 DOI: 10.1002/mas.21634] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/17/2019] [Accepted: 11/22/2019] [Indexed: 06/11/2023]
Abstract
Among the different techniques for mass analysis, ultra-high-resolution Fourier transform ion cyclotron resonance (FTICR) is the method of choice for highly complex samples, as it offers unrivaled mass accuracy and resolving power, combined with a high degree of flexibility in hybrid instruments as well as for ion activation techniques. FTICR instruments are readily embraced by the biological and biomedical research communities and applied over a wide range of applications for the analysis of biomolecules such as carbohydrates, lipids, nucleic acids, and proteins. In the field of natural organic matter (NOM) analysis, petroleum-related studies currently dominate FTICR-MS applications. Recently, however, there is a growing interest in developing high-performance MS methods for the characterization of NOM samples from natural aquatic and terrestrial environments. Here, we present an overview of FTICR-MS techniques for complex, non-petroleum NOM samples, including data analysis and novel tandem mass spectrometry (MS/MS) methods for structural classifications. © 2020 The Authors. Mass Spectrometry Reviews published by John Wiley & Sons Ltd.
Collapse
Affiliation(s)
- Yulin Qi
- Institute of Surface-Earth System Science, Tianjin University, Tianjin, China
- Department of Chemistry, Humboldt-Universität zu Berlin, Berlin, Germany
| | - Pingqing Fu
- Institute of Surface-Earth System Science, Tianjin University, Tianjin, China
| | - Dietrich A Volmer
- Department of Chemistry, Humboldt-Universität zu Berlin, Berlin, Germany
| |
Collapse
|
4
|
Madawala C, Lee HD, Kaluarachchi CP, Tivanski AV. Probing the Water Uptake and Phase State of Individual Sucrose Nanoparticles Using Atomic Force Microscopy. ACS EARTH & SPACE CHEMISTRY 2021; 5:2612-2620. [PMID: 34712889 PMCID: PMC8543754 DOI: 10.1021/acsearthspacechem.1c00101] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/13/2021] [Indexed: 06/13/2023]
Abstract
The effects of atmospheric aerosols on the climate and atmosphere of Earth can vary significantly depending upon their properties, including size, morphology, and phase state, all of which are influenced by varying relative humidity (RH) in the atmosphere. A significant fraction of atmospheric aerosols is below 100 nm in size. However, as a result of size limitations of conventional experimental techniques, how the particle-to-particle variability of the phase state of aerosols influences atmospheric processes is poorly understood. To address this issue, the atomic force microscopy (AFM) methodology that was previously established for sub-micrometer aerosols is extended to measure the water uptake and identify the phase state of individual sucrose nanoparticles. Quantified growth factors (GFs) of individual sucrose nanoparticles up to 60% RH were lower than expected values observed on the sub-micrometer sucrose particles. The effect could be attributed to the semisolid sucrose nanoparticle restructuring on a substrate. At RH > 60%, sucrose nanoparticles are liquid and GFs overlap well with the sub-micrometer particles and theoretical predictions. This suggests that quantification of GFs of nanoparticles may be inaccurate for the RH range where particles are semisolid but becomes accurate at elevated RH where particles are liquid. Despite this, however, the identified phase states of the nanoparticles were comparable to their sub-micrometer counterparts. The identified phase transitions between solid and semisolid and between semisolid and liquid for sucrose were at ∼18 and 60% RH, which are equivalent to viscosities of 1011.2 and 102.5 Pa s, respectively. This work demonstrates that measurements of the phase state using AFM are applicable to nanosized particles, even when the substrate alters the shape of semisolid nanoparticles and alters the GF.
Collapse
|
5
|
Kenseth CM, Hafeman NJ, Huang Y, Dalleska NF, Stoltz BM, Seinfeld JH. Synthesis of Carboxylic Acid and Dimer Ester Surrogates to Constrain the Abundance and Distribution of Molecular Products in α-Pinene and β-Pinene Secondary Organic Aerosol. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2020; 54:12829-12839. [PMID: 32813970 DOI: 10.1021/acs.est.0c01566] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Liquid chromatography/negative electrospray ionization mass spectrometry [LC/(-)ESI-MS] is routinely employed to characterize the identity and abundance of molecular products in secondary organic aerosol (SOA) derived from monoterpene oxidation. Due to a lack of authentic standards, however, commercial terpenoic acids (e.g., cis-pinonic acid) are typically used as surrogates to quantify both monomeric and dimeric SOA constituents. Here, we synthesize a series of enantiopure, pinene-derived carboxylic acid and dimer ester homologues. We find that the (-)ESI efficiencies of the dimer esters are 19-36 times higher than that of cis-pinonic acid, demonstrating that the mass contribution of dimers to monoterpene SOA has been significantly overestimated in past studies. Using the measured (-)ESI efficiencies of the carboxylic acids and dimer esters as more representative surrogates, we determine that molecular products measureable by LC/(-)ESI-MS account for only 21.8 ± 2.6% and 18.9 ± 3.2% of the mass of SOA formed from ozonolysis of α-pinene and β-pinene, respectively. The 28-36 identified monomers (C7-10H10-18O3-6) constitute 15.6-20.5% of total SOA mass, whereas only 1.3-3.3% of the SOA mass is attributable to the 46-62 identified dimers (C15-19H24-32O4-11). The distribution of identified α-pinene and β-pinene SOA molecular products is examined as a function of carbon number (nC), average carbon oxidation state (OS¯C), and volatility (C*). The observed order-of-magnitude difference in (-)ESI efficiency between monomers and dimers is expected to be broadly applicable to other biogenic and anthropogenic SOA systems analyzed via (-) or (+) LC/ESI-MS under various LC conditions, and demonstrates that the use of unrepresentative surrogates can lead to substantial systematic errors in quantitative LC/ESI-MS analyses of SOA.
Collapse
Affiliation(s)
- Christopher M Kenseth
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125, United States
| | - Nicholas J Hafeman
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125, United States
| | - Yuanlong Huang
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, California 91125, United States
| | - Nathan F Dalleska
- Environmental Analysis Center, Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, California 91125, United States
| | - Brian M Stoltz
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125, United States
| | - John H Seinfeld
- Divisions of Chemistry and Chemical Engineering and Engineering and Applied Science, California Institute of Technology, Pasadena, California 91125, United States
| |
Collapse
|
6
|
Khare P, Marcotte A, Sheu R, Walsh AN, Ditto JC, Gentner DR. Advances in offline approaches for trace measurements of complex organic compound mixtures via soft ionization and high-resolution tandem mass spectrometry. J Chromatogr A 2019; 1598:163-174. [DOI: 10.1016/j.chroma.2019.03.037] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2018] [Revised: 03/18/2019] [Accepted: 03/19/2019] [Indexed: 12/20/2022]
|
7
|
Schramm S, Zannoni N, Gros V, Tillmann R, Kiendler-Scharr A, Sarda-Estève R, Bridoux M. New application of direct analysis in real time high-resolution mass spectrometry for the untargeted analysis of fresh and aged secondary organic aerosols generated from monoterpenes. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2019; 33 Suppl 1:50-59. [PMID: 29971833 DOI: 10.1002/rcm.8228] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/26/2018] [Revised: 06/27/2018] [Accepted: 06/27/2018] [Indexed: 06/08/2023]
Abstract
RATIONALE Secondary organic aerosols (SOAs) represent a significant portion of total atmospheric aerosols. They are generated by the oxidation of volatile organic compounds (VOCs), and particularly biogenic VOCs (BVOCs). The analysis of such samples is usually performed by targeted methods that often require time-consuming preparation steps that can induce loss of compounds and/or sample contaminations. METHODS Recently, untargeted methods using high-resolution mass spectrometry (HRMS) have been successfully employed for a broad characterization of chemicals in SOAs. Herein we propose a new application of the direct analysis in real time (DART) ionization method combined with HRMS to quickly detect several hundred chemicals in SOAs collected on a quartz filter without sample preparation or separation techniques. RESULTS The reproducibility of measurements was good, with several hundred elemental compositions common to three different replicates. The relative standard deviations of the intensities of the chemical families ranged from 6% to 35%, with sufficient sensitivity to allow the unambiguous detection of 4 ng/mm2 of pinic acid. The presence of oligomers and specific tracers was highlighted by MSn (n ≤ 4) experiments, an achievement that is difficult to attain with other ultrahigh-resolution mass spectrometers. Contributions of this untargeted DART-HRMS method were illustrated by the analysis of fresh and aged SOAs from different gaseous precursors such as limonene, a β-pinene/limonene mixture or scots pines emissions. CONCLUSIONS The results show that it is possible to use DART-HRMS for the identification of tracers of specific aging reactions, or for the identification of aerosols from specific biogenic precursors.
Collapse
Affiliation(s)
- Sébastien Schramm
- LCP-A2MC, Université de Lorraine ICPM, 1 boulevard Arago, 57078, Metz Cedex, 03, France
| | | | | | - Ralf Tillmann
- Institut für Chemie und Dynamik der Geosphäre 2, Forschungszentrum Jülich GmbH, Jülich, Germany
| | - Astrid Kiendler-Scharr
- Institut für Chemie und Dynamik der Geosphäre 2, Forschungszentrum Jülich GmbH, Jülich, Germany
| | | | | |
Collapse
|
8
|
JIANG HX, LI J, TANG J, MO YZ, ZHANG G. Applications of High-Resolution Mass Spectrometry in Studies of Brown Carbon. CHINESE JOURNAL OF ANALYTICAL CHEMISTRY 2018. [DOI: 10.1016/s1872-2040(18)61115-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
|
9
|
Synergistic O 3 + OH oxidation pathway to extremely low-volatility dimers revealed in β-pinene secondary organic aerosol. Proc Natl Acad Sci U S A 2018; 115:8301-8306. [PMID: 30076229 DOI: 10.1073/pnas.1804671115] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
Dimeric compounds contribute significantly to the formation and growth of atmospheric secondary organic aerosol (SOA) derived from monoterpene oxidation. However, the mechanisms of dimer production, in particular the relevance of gas- vs. particle-phase chemistry, remain unclear. Here, through a combination of mass spectrometric, chromatographic, and synthetic techniques, we identify a suite of dimeric compounds (C15-19H24-32O5-11) formed from concerted O3 and OH oxidation of β-pinene (i.e., accretion of O3- and OH-derived products/intermediates). These dimers account for an appreciable fraction (5.9-25.4%) of the β-pinene SOA mass and are designated as extremely low-volatility organic compounds. Certain dimers, characterized as covalent dimer esters, are conclusively shown to form through heterogeneous chemistry, while evidence of dimer production via gas-phase reactions is also presented. The formation of dimers through synergistic O3 + OH oxidation represents a potentially significant, heretofore-unidentified source of low-volatility monoterpene SOA. This reactivity also suggests that the current treatment of SOA formation as a sum of products originating from the isolated oxidation of individual precursors fails to accurately reflect the complexity of oxidation pathways at play in the real atmosphere. Accounting for the role of synergistic oxidation in ambient SOA formation could help to resolve the discrepancy between the measured atmospheric burden of SOA and that predicted by regional air quality and global climate models.
Collapse
|
10
|
Hong S, Ratpukdi T, Sivaguru J, Khan E. Photolysis of glutaraldehyde in brine: A showcase study for removal of a common biocide in oil and gas produced water. JOURNAL OF HAZARDOUS MATERIALS 2018; 353:254-260. [PMID: 29677527 DOI: 10.1016/j.jhazmat.2018.03.056] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/06/2017] [Revised: 03/26/2018] [Accepted: 03/27/2018] [Indexed: 06/08/2023]
Abstract
Glutaraldehyde (GA) has been used extensively as a biocide in hydraulic fracturing fluid leading to its presence in oil and gas produced water. In this study, photolysis was used to degrade GA from brine solutions simulating produced water. Photolysis of GA was performed under ultraviolet (UV) irradiation. GA can be photolyzed by UV at all studied conditions with the efficiency ranging from 52 to 85% within one hour irradiation. Photolysis of GA followed pseudo-first order kinetics. A photolysis rate constant of GA at 0.1 mM in 200 g/L of salt at pH 7 was 0.0269 min-1 with a quantum yield of 0.0549 under 224 W illumination. The degradation rate of GA increased with increasing incident light intensity and decreasing pH. Increasing initial GA concentration resulted in decreasing degradation rate of GA. The degradation of GA was affected by salt concentration. At lower salt concentrations, notable retardation of GA photodegradation rate was observed while at higher salt concentrations GA photodegradation was improved compared to those without salt. OH was more dominant in sample without salt than sample with salt suggesting different photolytic mechanisms, indirect and direct photolysis, respectively. Oligomers were identified as the main photoproducts of GA photolysis.
Collapse
Affiliation(s)
- Soklida Hong
- Environmental and Conservation Sciences Program, North Dakota State University, Fargo, ND 58108, USA; International Postgraduate Programs in Environmental Management, Graduate School Chulalongkorn University, Bangkok 10330, Thailand.
| | - Thunyalux Ratpukdi
- Department of Environmental Engineering, Khon Kaen University, Khon Kaen 40002, Thailand.
| | - Jayaraman Sivaguru
- Center for Photochemical Sciences and Department of Chemistry, Bowling Green State University, Bowling Green, OH, 43403, USA.
| | - Eakalak Khan
- Department of Civil and Environmental Engineering and Construction, University of Nevada, Las Vegas, NV 89154, USA.
| |
Collapse
|
11
|
He Q, Bluvshtein N, Segev L, Meidan D, Flores JM, Brown SS, Brune W, Rudich Y. Evolution of the Complex Refractive Index of Secondary Organic Aerosols during Atmospheric Aging. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2018; 52:3456-3465. [PMID: 29461820 DOI: 10.1021/acs.est.7b05742] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
The wavelength-dependence of the complex refractive indices (RI) in the visible spectral range of secondary organic aerosols (SOA) are rarely studied, and the evolution of the RI with atmospheric aging is largely unknown. In this study, we applied a novel white light-broadband cavity enhanced spectroscopy to measure the changes in the RI (400-650 nm) of β-pinene and p-xylene SOA produced and aged in an oxidation flow reactor, simulating daytime aging under NO x-free conditions. It was found that these SOA are not absorbing in the visible range, and that the real part of the RI, n, shows a slight spectral dependence in the visible range. With increased OH exposure, n first increased and then decreased, possibly due to an increase in aerosol density and chemical mean polarizability for SOA produced at low OH exposures, and a decrease in chemical mean polarizability for SOA produced at high OH exposures, respectively. A simple radiative forcing calculation suggests that atmospheric aging can introduce more than 40% uncertainty due to the changes in the RI for aged SOA.
Collapse
Affiliation(s)
- Quanfu He
- Department of Earth and Planetary Sciences , Weizmann Institute of Science , Rehovot 76100 , Israel
| | - Nir Bluvshtein
- Department of Earth and Planetary Sciences , Weizmann Institute of Science , Rehovot 76100 , Israel
| | - Lior Segev
- Department of Earth and Planetary Sciences , Weizmann Institute of Science , Rehovot 76100 , Israel
| | - Daphne Meidan
- Department of Earth and Planetary Sciences , Weizmann Institute of Science , Rehovot 76100 , Israel
| | - J Michel Flores
- Department of Earth and Planetary Sciences , Weizmann Institute of Science , Rehovot 76100 , Israel
| | - Steven S Brown
- Cooperative Institute for Research in Environmental Sciences , University of Colorado , 216 UCB , Boulder , Colorado 80309 , United States
- Chemical Sciences Division, Earth System Research Laboratory, National Oceanic and Atmospheric Administration, 325 Broadway , Boulder , Colorado 80305 , United States
| | - William Brune
- Department of Meteorology and Atmospheric Science , The Pennsylvania State University , University Park , Pennsylvania 16802-5013 , United States
| | - Yinon Rudich
- Department of Earth and Planetary Sciences , Weizmann Institute of Science , Rehovot 76100 , Israel
| |
Collapse
|
12
|
Baltensperger U. Spiers Memorial Lecture. Introductory lecture: chemistry in the urban atmosphere. Faraday Discuss 2018; 189:9-29. [PMID: 27247983 DOI: 10.1039/c6fd00065g] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
The urban atmosphere is characterised by a multitude of complex processes. Gaseous and particulate components are continuously emitted into the atmosphere from many different sources. These components are then dispersed in the urban atmosphere via turbulent mixing. Numerous chemical reactions modify the gas phase chemistry on multiple time scales, producing secondary pollutants. Through partitioning, the chemical and physical properties of the aerosol particles are also constantly changing as a consequence of dispersion and gas phase chemistry. This review presents an overview of the involved processes, focusing on the contributions presented at this conference and putting them into a broader context. Advanced methods for aerosol source apportionment are presented as well, followed by some aspects of health effects related to air pollution.
Collapse
Affiliation(s)
- Urs Baltensperger
- Laboratory of Atmospheric Chemistry, Paul Scherrer Institute, 5232 Villigen, Switzerland.
| |
Collapse
|
13
|
Gao X, Cai C, Ma J, Zhang Y. Repartitioning of glycerol between levitated and surrounding deposited glycerol/NaNO 3/H 2O droplets. ROYAL SOCIETY OPEN SCIENCE 2018; 5:170819. [PMID: 29410802 PMCID: PMC5792879 DOI: 10.1098/rsos.170819] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/02/2017] [Accepted: 11/24/2017] [Indexed: 06/07/2023]
Abstract
Repartitioning of semi-volatile organic compounds (SVOCs) between particles is an important process to understand the particle growth and shrinkage in the atmosphere environment. Here, by using optical tweezers coupled with cavity-enhanced Raman spectroscopy, we report the repartitioning of glycerol between a levitated glycerol/NaNO3/H2O droplet and surrounding glycerol/NaNO3/H2O droplets deposited on the inner wall of a chamber with different organic to inorganic molar ratios (OIRs). For the high OIR with 3 : 1, no NaNO3 crystallization occurs both for levitated and deposited droplets in the whole relative humidity (RH) range, the radius of the levitated droplet decreases slowly due to the evaporation of glycerol from the levitated droplet at constant RHs. The levitated droplets radii with OIR of 1 : 1 and 1 : 3 increase with constant RHs that are lower than 45.3% and 55.7%, respectively, indicating that the repartitioning of glycerol occurs. The reason is that NaNO3 in the deposited droplets is crystallized when RH is lower than 45.3% for 1 : 1 or 55.7% for 1 : 3. So the vapour pressure of glycerol at the surface of deposited droplets is higher than that of the levitated droplet which always remains as liquid droplet without NaNO3 crystallization, resulting in the transfer of glycerol from the deposited ones to the levitated one. The process of the glycerol repartitioning we discussed herein is a useful model to interpret the repartitioning of SVOCs between the externally mixed particles with different phase states.
Collapse
Affiliation(s)
| | | | - Jiabi Ma
- Authors for correspondence: Jiabi Ma e-mail:
| | | |
Collapse
|
14
|
Lee HD, Ray KK, Tivanski AV. Solid, Semisolid, and Liquid Phase States of Individual Submicrometer Particles Directly Probed Using Atomic Force Microscopy. Anal Chem 2017; 89:12720-12726. [DOI: 10.1021/acs.analchem.7b02755] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Affiliation(s)
- Hansol D. Lee
- Department
of Chemistry, University of Iowa, Iowa City, Iowa 52242, United States
| | - Kamal K. Ray
- Department
of Chemistry, University of Iowa, Iowa City, Iowa 52242, United States
| | - Alexei V. Tivanski
- Department
of Chemistry, University of Iowa, Iowa City, Iowa 52242, United States
| |
Collapse
|
15
|
Kristensen K, Jensen LN, Glasius M, Bilde M. The effect of sub-zero temperature on the formation and composition of secondary organic aerosol from ozonolysis of alpha-pinene. ENVIRONMENTAL SCIENCE. PROCESSES & IMPACTS 2017; 19:1220-1234. [PMID: 28805852 DOI: 10.1039/c7em00231a] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
This study presents a newly constructed temperature controlled cold-room smog chamber at Aarhus University, Denmark. The chamber is herein utilized to study the effect of sub-zero temperature on the formation and chemical composition of secondary organic aerosol (SOA) from ozone initiated oxidation of α-pinene. The chemical composition of α-pinene SOA formed from dark ozonolysis of α-pinene at 293 K and 258 K was investigated using High-Resolution Time-of-Flight Aerosol Mass Spectrometry (HR-ToF-AMS) and Ultra-High Performance Liquid Chromatography/Electrospray Ionization Quadrupole Time-of-Flight Mass Spectrometry (UHPLC/ESI-qToF-MS). For comparison, an OH-initiated oxidation experiment was performed at 293 K. In ozonolysis experiments it was found that oxygen-to-carbon (O : C) ratios were higher in the particles formed at 293 K compared to 258 K. A total of 16 different organic acids and 30 dimers esters were quantified in the collected particles composing up to 34% of the total α-pinene SOA mass with increased mass fraction of carboxylic acids in particles from α-pinene ozonolysis at 258 K compared to 293 K. In contrast, dimer esters showed suppressed formation at the sub-zero reaction temperature, thus contributing 3% to SOA mass at 258 K while contributing 9% at 293 K. SOA formed in the OH-initiated oxidation of α-pinene at 293 K resulted in low concentrations of dimer esters supporting Criegee intermediates as a possible pathway to dimer ester formation. Vapour pressure estimates of the identified carboxylic acids and dimer esters are presented and show how otherwise semi-volatile carboxylic acids at sufficiently low temperatures may classify as low or even extremely low volatile organic compounds (ELVOC), thus may add to an enhanced particle formation observed at the sub-zero temperature through gas-to-particle conversion. The change in chemical composition of the SOA particles with temperature is ascribed to a combination of effects: the decreased vapour pressures and hence increased condensation of carboxylic acids from the gas phase to the particle phase along with suppressed formation of the high molecular weight dimer esters and different gas and particle phase chemistry results in particles of different chemical composition as a consequence of low reaction temperatures.
Collapse
Affiliation(s)
- K Kristensen
- Department of Chemistry, Aarhus University, DK-8000 Aarhus C., Denmark.
| | | | | | | |
Collapse
|
16
|
Giorio C, Monod A, Brégonzio-Rozier L, DeWitt HL, Cazaunau M, Temime-Roussel B, Gratien A, Michoud V, Pangui E, Ravier S, Zielinski AT, Tapparo A, Vermeylen R, Claeys M, Voisin D, Kalberer M, Doussin JF. Cloud Processing of Secondary Organic Aerosol from Isoprene and Methacrolein Photooxidation. J Phys Chem A 2017; 121:7641-7654. [PMID: 28902512 PMCID: PMC5642272 DOI: 10.1021/acs.jpca.7b05933] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2017] [Revised: 09/02/2017] [Indexed: 11/30/2022]
Abstract
Aerosol-cloud interaction contributes to the largest uncertainties in the estimation and interpretation of the Earth's changing energy budget. The present study explores experimentally the impacts of water condensation-evaporation events, mimicking processes occurring in atmospheric clouds, on the molecular composition of secondary organic aerosol (SOA) from the photooxidation of methacrolein. A range of on- and off-line mass spectrometry techniques were used to obtain a detailed chemical characterization of SOA formed in control experiments in dry conditions, in triphasic experiments simulating gas-particle-cloud droplet interactions (starting from dry conditions and from 60% relative humidity (RH)), and in bulk aqueous-phase experiments. We observed that cloud events trigger fast SOA formation accompanied by evaporative losses. These evaporative losses decreased SOA concentration in the simulation chamber by 25-32% upon RH increase, while aqueous SOA was found to be metastable and slowly evaporated after cloud dissipation. In the simulation chamber, SOA composition measured with a high-resolution time-of-flight aerosol mass spectrometer, did not change during cloud events compared with high RH conditions (RH > 80%). In all experiments, off-line mass spectrometry techniques emphasize the critical role of 2-methylglyceric acid as a major product of isoprene chemistry, as an important contributor to the total SOA mass (15-20%) and as a key building block of oligomers found in the particulate phase. Interestingly, the comparison between the series of oligomers obtained from experiments performed under different conditions show a markedly different reactivity. In particular, long reaction times at high RH seem to create the conditions for aqueous-phase processing to occur in a more efficient manner than during two relatively short cloud events.
Collapse
Affiliation(s)
- Chiara Giorio
- Department
of Chemistry, University of Cambridge, Cambridge CB2 1EW, U.K.
- Aix
Marseille Univ, CNRS, LCE, Marseille, France
| | - Anne Monod
- Aix
Marseille Univ, CNRS, LCE, Marseille, France
| | - Lola Brégonzio-Rozier
- Laboratoire
Interuniversitaire des Systèmes Atmosphériques, UMR7583, CNRS, Université Paris-Est-Créteil
et Université Paris Diderot, Institut Pierre Simon Laplace, Créteil, France
| | | | - Mathieu Cazaunau
- Laboratoire
Interuniversitaire des Systèmes Atmosphériques, UMR7583, CNRS, Université Paris-Est-Créteil
et Université Paris Diderot, Institut Pierre Simon Laplace, Créteil, France
| | | | - Aline Gratien
- Laboratoire
Interuniversitaire des Systèmes Atmosphériques, UMR7583, CNRS, Université Paris-Est-Créteil
et Université Paris Diderot, Institut Pierre Simon Laplace, Créteil, France
| | - Vincent Michoud
- Laboratoire
Interuniversitaire des Systèmes Atmosphériques, UMR7583, CNRS, Université Paris-Est-Créteil
et Université Paris Diderot, Institut Pierre Simon Laplace, Créteil, France
| | - Edouard Pangui
- Laboratoire
Interuniversitaire des Systèmes Atmosphériques, UMR7583, CNRS, Université Paris-Est-Créteil
et Université Paris Diderot, Institut Pierre Simon Laplace, Créteil, France
| | | | | | - Andrea Tapparo
- Dipartimento
di Scienze Chimiche, Università degli
Studi di Padova, Padova 35131, Italy
| | - Reinhilde Vermeylen
- Department
of Pharmaceutical Sciences, University of
Antwerp (Campus Drie Eiken), Universiteitsplein 1, BE-2610 Antwerp, Belgium
| | - Magda Claeys
- Department
of Pharmaceutical Sciences, University of
Antwerp (Campus Drie Eiken), Universiteitsplein 1, BE-2610 Antwerp, Belgium
| | - Didier Voisin
- Universités
Joseph Fourier-Grenoble 1, CNRS, UMR5183,
Laboratoire de Glaciologie et Géophysique de l’Environnement, 38402 Saint Martin
d’Hères, France
| | - Markus Kalberer
- Department
of Chemistry, University of Cambridge, Cambridge CB2 1EW, U.K.
| | - Jean-François Doussin
- Laboratoire
Interuniversitaire des Systèmes Atmosphériques, UMR7583, CNRS, Université Paris-Est-Créteil
et Université Paris Diderot, Institut Pierre Simon Laplace, Créteil, France
| |
Collapse
|
17
|
Romonosky DE, Li Y, Shiraiwa M, Laskin A, Laskin J, Nizkorodov SA. Aqueous Photochemistry of Secondary Organic Aerosol of α-Pinene and α-Humulene Oxidized with Ozone, Hydroxyl Radical, and Nitrate Radical. J Phys Chem A 2017; 121:1298-1309. [DOI: 10.1021/acs.jpca.6b10900] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- Dian E. Romonosky
- Department
of Chemistry, University of California, Irvine, California 92697, United States
| | - Ying Li
- National Institute for Environmental Studies, Tsukuba, Ibaraki 305-8506, Japan
| | - Manabu Shiraiwa
- Department
of Chemistry, University of California, Irvine, California 92697, United States
| | | | | | - Sergey A. Nizkorodov
- Department
of Chemistry, University of California, Irvine, California 92697, United States
| |
Collapse
|
18
|
Chen J, Li C, Ristovski Z, Milic A, Gu Y, Islam MS, Wang S, Hao J, Zhang H, He C, Guo H, Fu H, Miljevic B, Morawska L, Thai P, Lam YF, Pereira G, Ding A, Huang X, Dumka UC. A review of biomass burning: Emissions and impacts on air quality, health and climate in China. THE SCIENCE OF THE TOTAL ENVIRONMENT 2017; 579:1000-1034. [PMID: 27908624 DOI: 10.1016/j.scitotenv.2016.11.025] [Citation(s) in RCA: 347] [Impact Index Per Article: 49.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/01/2016] [Revised: 11/04/2016] [Accepted: 11/04/2016] [Indexed: 05/17/2023]
Abstract
Biomass burning (BB) is a significant air pollution source, with global, regional and local impacts on air quality, public health and climate. Worldwide an extensive range of studies has been conducted on almost all the aspects of BB, including its specific types, on quantification of emissions and on assessing its various impacts. China is one of the countries where the significance of BB has been recognized, and a lot of research efforts devoted to investigate it, however, so far no systematic reviews were conducted to synthesize the information which has been emerging. Therefore the aim of this work was to comprehensively review most of the studies published on this topic in China, including literature concerning field measurements, laboratory studies and the impacts of BB indoors and outdoors in China. In addition, this review provides insights into the role of wildfire and anthropogenic BB on air quality and health globally. Further, we attempted to provide a basis for formulation of policies and regulations by policy makers in China.
Collapse
Affiliation(s)
- Jianmin Chen
- Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention, Department of Environmental Science and Engineering, Institute of Atmospheric Sciences, Fudan University, Shanghai 200433, China; Collaborative Innovation Center of Climate Change, School of Atmospheric Sciences, Nanjing University, Nanjing 210023, China.
| | - Chunlin Li
- Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention, Department of Environmental Science and Engineering, Institute of Atmospheric Sciences, Fudan University, Shanghai 200433, China
| | - Zoran Ristovski
- International Laboratory for Air Quality and Health, Queensland University of Technology, Brisbane, QLD 4001, Australia
| | - Andelija Milic
- International Laboratory for Air Quality and Health, Queensland University of Technology, Brisbane, QLD 4001, Australia
| | - Yuantong Gu
- International Laboratory for Air Quality and Health, Queensland University of Technology, Brisbane, QLD 4001, Australia
| | - Mohammad S Islam
- International Laboratory for Air Quality and Health, Queensland University of Technology, Brisbane, QLD 4001, Australia
| | - Shuxiao Wang
- State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China
| | - Jiming Hao
- State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China.
| | - Hefeng Zhang
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China
| | - Congrong He
- International Laboratory for Air Quality and Health, Queensland University of Technology, Brisbane, QLD 4001, Australia
| | - Hai Guo
- Department of Civil and Environmental Engineering, Hong Kong Polytechnic University, Hong Kong, China
| | - Hongbo Fu
- Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention, Department of Environmental Science and Engineering, Institute of Atmospheric Sciences, Fudan University, Shanghai 200433, China
| | - Branka Miljevic
- International Laboratory for Air Quality and Health, Queensland University of Technology, Brisbane, QLD 4001, Australia
| | - Lidia Morawska
- International Laboratory for Air Quality and Health, Queensland University of Technology, Brisbane, QLD 4001, Australia.
| | - Phong Thai
- International Laboratory for Air Quality and Health, Queensland University of Technology, Brisbane, QLD 4001, Australia
| | - Yun Fat Lam
- School of Energy and Environment, City University of Hong Kong, Hong Kong, China
| | - Gavin Pereira
- School of Public Health, Curtin University, Perth, WA, 6000, Australia
| | - Aijun Ding
- Collaborative Innovation Center of Climate Change, School of Atmospheric Sciences, Nanjing University, Nanjing 210023, China
| | - Xin Huang
- Collaborative Innovation Center of Climate Change, School of Atmospheric Sciences, Nanjing University, Nanjing 210023, China
| | - Umesh C Dumka
- Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention, Department of Environmental Science and Engineering, Institute of Atmospheric Sciences, Fudan University, Shanghai 200433, China; Aryabhatta Research Institute of Observational Sciences, Manora Peak, Nainital 263001, India
| |
Collapse
|
19
|
Longnecker K, Kujawinski EB. Using network analysis to discern compositional patterns in ultrahigh-resolution mass spectrometry data of dissolved organic matter. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2016; 30:2388-2394. [PMID: 27524402 DOI: 10.1002/rcm.7719] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/17/2016] [Revised: 08/09/2016] [Accepted: 08/10/2016] [Indexed: 05/22/2023]
Abstract
RATIONALE Marine dissolved organic matter (DOM) has long been recognized as a large and dynamic component of the global carbon cycle. Yet, DOM is chemically varied and complex and these attributes present challenges to researchers interested in addressing questions about the role of DOM in global biogeochemical cycles. METHODS Organic matter extracts from seawater were analyzed by direct infusion with electrospray ionization into a Fourier transform ion cyclotron resonance mass spectrometer. Network analysis was used to quantify the number of chemical transformations between mass-to-charge values in each sample. The network of chemical transformations was calculated using the MetaNetter plug-in within Cytoscape. The chemical transformations serve as markers for the shared structural characteristics of compounds within complex DOM. RESULTS Network analysis revealed that transformations involving selected sulfur-containing moieties and isomers of amino acids were more prevalent in the deep sea than in the surface ocean. Common chemical transformations were not significantly different between the deep sea and surface ocean. Network analysis complements existing computational tools used to analyze ultrahigh-resolution mass spectrometry data. CONCLUSIONS This combination of ultrahigh-resolution mass spectrometry with novel computational tools has identified new potential building blocks of organic compounds in the deep sea, including the unexpected importance of dissolved organic sulfur components. The method described here can be readily applied by researchers to analyze heterogeneous and complex DOM. Copyright © 2016 John Wiley & Sons, Ltd.
Collapse
Affiliation(s)
- Krista Longnecker
- Woods Hole Oceanographic Institution, Marine Chemistry and Geochemistry, Woods Hole, MA, 02543, USA.
| | - Elizabeth B Kujawinski
- Woods Hole Oceanographic Institution, Marine Chemistry and Geochemistry, Woods Hole, MA, 02543, USA
| |
Collapse
|
20
|
Duan FK, He KB, Ma YL, Ihozaki T, Kawasaki H, Arakawa R, Kitayama S, Tujimoto K, Huang T, Kimoto T, Furutani H, Toyoda M. High molecular weight organic compounds (HMW-OCs) in severe winter haze: Direct observation and insights on the formation mechanism. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2016; 218:289-296. [PMID: 27423501 DOI: 10.1016/j.envpol.2016.07.004] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/01/2016] [Revised: 06/29/2016] [Accepted: 07/01/2016] [Indexed: 05/13/2023]
Abstract
High molecular weight organic compounds (HMW-OCs), formed as secondary organic aerosols (SOA), have been reported in many laboratory studies. However, little evidence of HMW-OCs formation, in particular during winter season in the real atmosphere, has been reported. In January 2013, Beijing faced historically severe haze pollution, in which the hourly PM2.5 concentration reached as high as 974 μg m-3. Four typical haze events (HE1 to HE4) were identified, and HE2 (Jan. 9-16) was the most serious of these. Based on the hourly observed chemical composition of PM2.5 and the daily organic composition analyzed by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS), we found that abundant ion peaks in m/z 200-850 appeared on heavy haze days, whereas these were negligible on a clear day, indicating the existence of HMW-OCs in the wintertime haze. A negative nonlinear correlation between HMW-OCs and O3 suggested that gas oxidation was not likely to be the dominant mechanism for HMW-OCs formation. During the heavy haze events, the relative humidity and mass ratio of H2O/PM2.5 reached as high as 80% and 0.2, respectively. The high water content and its good positive correlation with HMW-OCs indicated that an aqueous-phase process may be a significant pathway in wintertime. The evidence that acidity was much higher during HE2 (0.37 μg m-3) than on other days, as well as its strong correlation with HMW-OCs, indicated that acid-catalyzed reactions likely resulted in HMW-OCs formation during the heavy winter haze in Beijing.
Collapse
Affiliation(s)
- F K Duan
- State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing, 100084, China; State Environmental Protection Key Laboratory of Sources and Control of Air Pollution Complex, Tsinghua University, Beijing, 100084, China; Beijing Key Laboratory of Indoor Air Quality Evaluation and Control, Tsinghua University, Beijing, 100084, China.
| | - K B He
- State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing, 100084, China; State Environmental Protection Key Laboratory of Sources and Control of Air Pollution Complex, Tsinghua University, Beijing, 100084, China; Beijing Key Laboratory of Indoor Air Quality Evaluation and Control, Tsinghua University, Beijing, 100084, China.
| | - Y L Ma
- State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing, 100084, China; State Environmental Protection Key Laboratory of Sources and Control of Air Pollution Complex, Tsinghua University, Beijing, 100084, China; Beijing Key Laboratory of Indoor Air Quality Evaluation and Control, Tsinghua University, Beijing, 100084, China
| | - T Ihozaki
- Department of Chemistry and Materials Engineering, Kansai University, Suita, 564-8680, Japan
| | - H Kawasaki
- Department of Chemistry and Materials Engineering, Kansai University, Suita, 564-8680, Japan
| | - R Arakawa
- Department of Chemistry and Materials Engineering, Kansai University, Suita, 564-8680, Japan
| | - S Kitayama
- Kimoto Electric Co. Ltd, Funahashi-Cho, Tennouji-Ku, Osaka, 543-0024, Japan
| | - K Tujimoto
- Kimoto Electric Co. Ltd, Funahashi-Cho, Tennouji-Ku, Osaka, 543-0024, Japan
| | - T Huang
- Kimoto Electric Co. Ltd, Funahashi-Cho, Tennouji-Ku, Osaka, 543-0024, Japan
| | - T Kimoto
- Kimoto Electric Co. Ltd, Funahashi-Cho, Tennouji-Ku, Osaka, 543-0024, Japan
| | - H Furutani
- Project Research Center for Fundamental Sciences, Graduate School of Science, Osaka University, 1-1 Machikaneyama, Toyonaka, Osaka, 560-0043, Japan; Center for Scientific Instrument Renovation and Manufacturing Support, Osaka University, 1-2 Machikaneyama, Toyonaka, Osaka, 560-0043, Japan
| | - M Toyoda
- Project Research Center for Fundamental Sciences, Graduate School of Science, Osaka University, 1-1 Machikaneyama, Toyonaka, Osaka, 560-0043, Japan
| |
Collapse
|
21
|
Detailed Source-Specific Molecular Composition of Ambient Aerosol Organic Matter Using Ultrahigh Resolution Mass Spectrometry and 1H NMR. ATMOSPHERE 2016. [DOI: 10.3390/atmos7060079] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
|
22
|
Tu P, Hall WA, Johnston MV. Characterization of Highly Oxidized Molecules in Fresh and Aged Biogenic Secondary Organic Aerosol. Anal Chem 2016; 88:4495-501. [PMID: 27000653 PMCID: PMC4924475 DOI: 10.1021/acs.analchem.6b00378] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
In this work, highly oxidized multifunctional molecules (HOMs) in fresh and aged secondary organic aerosol (SOA) derived from biogenic precursors are characterized with high-resolution mass spectrometry. Fresh SOA was generated by mixing ozone with a biogenic precursor (β-pinene, limonene, α-pinene) in a flow tube reactor. Aging was performed by passing the fresh SOA through a photochemical reactor where it reacted with hydroxyl radicals. Although these aerosols were as a whole not highly oxidized, molecular analysis identified a significant number of HOMs embedded within it. HOMs in fresh SOA consisted mostly of monomers and dimers, which is consistent with condensation of extremely low-volatility organic compounds (ELVOCs) that have been detected in the gas phase in previous studies and linked to SOA particle formation. Aging caused an increase in the average number of carbon atoms per molecule of the HOMs, which is consistent with particle phase oxidation of (less oxidized) oligomers already existing in fresh SOA. HOMs having different combinations of oxygen-to-carbon ratio, hydrogen-to-carbon ratio and average carbon oxidation state are discussed and compared to low volatility oxygenated organic aerosol (LVOOA), which has been identified in ambient aerosol based on average elemental composition but not fully understood at a molecular level. For the biogenic precursors and experimental conditions studied, HOMs in fresh biogenic SOA have molecular formulas more closely resembling LVOOA than HOMs in aged SOA, suggesting that aging of biogenic SOA is not a good surrogate for ambient LVOOA.
Collapse
Affiliation(s)
- Peijun Tu
- Department of Chemistry and Biochemistry, University of Delaware, Newark, Delaware 19716, USA
| | - Wiley A. Hall
- DFA of California, 1855 South Van Ness Avenue, Fresno, CA 93721, USA
| | - Murray V. Johnston
- Department of Chemistry and Biochemistry, University of Delaware, Newark, Delaware 19716, USA
| |
Collapse
|
23
|
Glasius M, Goldstein AH. Recent Discoveries and Future Challenges in Atmospheric Organic Chemistry. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2016; 50:2754-64. [PMID: 26862779 DOI: 10.1021/acs.est.5b05105] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
Earth's atmosphere contains a multitude of organic compounds, which differ by orders of magnitude regarding fundamental properties such as volatility, reactivity, and propensity to form cloud droplets, affecting their impact on global climate and human health. Despite recent major research efforts and advances, there are still substantial gaps in understanding of atmospheric organic chemistry, hampering efforts to understand, model, and mitigate environmental problems such as aerosol formation in both polluted urban and more pristine regions. The analytical toolbox available for chemists to study atmospheric organic components has expanded considerably during the past decade, opening new windows into speciation, time resolution and detection of reactive and semivolatile compounds at low concentrations. This has provided unprecedented opportunities, but also unveiled new scientific challenges. Specific groundbreaking examples include the role of epoxides in aerosol formation especially from isoprene, the importance of highly oxidized, reactive organics in air-surface processes (whether atmosphere-biosphere exchange or aerosols), as well as the extent of interactions of anthropogenic and biogenic emissions and the resulting impact on atmospheric organic chemistry.
Collapse
Affiliation(s)
- Marianne Glasius
- Department of Chemistry and iNANO, Aarhus University , 8000 Aarhus C, Denmark
| | - Allen H Goldstein
- Department of Environmental Science, Policy and Management, and Department of Civil and Environmental Engineering, University of California , Berkeley, California 94720, United States
| |
Collapse
|
24
|
Hosny NA, Fitzgerald C, Vyšniauskas A, Athanasiadis A, Berkemeier T, Uygur N, Pöschl U, Shiraiwa M, Kalberer M, Pope FD, Kuimova MK. Direct imaging of changes in aerosol particle viscosity upon hydration and chemical aging. Chem Sci 2015; 7:1357-1367. [PMID: 29910892 PMCID: PMC5975791 DOI: 10.1039/c5sc02959g] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2015] [Accepted: 11/07/2015] [Indexed: 12/22/2022] Open
Abstract
We report quantitative, real-time, online observations of microscopic viscosity changes in aerosol particles of atmospherically relevant composition, using fluorescence lifetime imaging (FLIM) of viscosity.
Organic aerosol particles (OA) play major roles in atmospheric chemistry, climate, and public health. Aerosol particle viscosity is highly important since it can determine the ability of chemical species such as oxidants, organics or water to diffuse into the particle bulk. Recent measurements indicate that OA may be present in highly viscous states, however, diffusion rates of small molecules such as water are not limited by these high viscosities. Direct observational evidence of kinetic barriers caused by high viscosity and low diffusivity in aerosol particles were not available until recently; and techniques that are able to dynamically quantify and track viscosity changes during atmospherically relevant processes are still unavailable for atmospheric aerosols. Here we report quantitative, real-time, online observations of microscopic viscosity changes in aerosol particles of atmospherically relevant composition, using fluorescence lifetime imaging (FLIM) of viscosity. We show that microviscosity in ozonated oleic acid droplets and secondary organic aerosol (SOA) particles formed by ozonolysis of myrcene increases substantially with decreasing humidity and atmospheric oxidative aging processes. Furthermore, we found unexpected heterogeneities of microviscosity inside individual aerosol particles. The results of this study enhance our understanding of organic aerosol processes on microscopic scales and may have important implications for the modeling of atmospheric aerosol growth, composition and interactions with trace gases and clouds.
Collapse
Affiliation(s)
- N A Hosny
- Department of Chemistry , Imperial College London , London , SW7 2AZ , UK .
| | - C Fitzgerald
- Department of Chemistry , University of Cambridge , Cambridge , CB2 1EW , UK .
| | - A Vyšniauskas
- Department of Chemistry , Imperial College London , London , SW7 2AZ , UK .
| | - A Athanasiadis
- Department of Chemistry , Imperial College London , London , SW7 2AZ , UK .
| | - T Berkemeier
- Multiphase Chemistry Department , Max Planck Institute for Chemistry , Hahn-Meitner Weg 1 , 55128 , Mainz , Germany
| | - N Uygur
- Multiphase Chemistry Department , Max Planck Institute for Chemistry , Hahn-Meitner Weg 1 , 55128 , Mainz , Germany
| | - U Pöschl
- Multiphase Chemistry Department , Max Planck Institute for Chemistry , Hahn-Meitner Weg 1 , 55128 , Mainz , Germany
| | - M Shiraiwa
- Multiphase Chemistry Department , Max Planck Institute for Chemistry , Hahn-Meitner Weg 1 , 55128 , Mainz , Germany
| | - M Kalberer
- Department of Chemistry , University of Cambridge , Cambridge , CB2 1EW , UK .
| | - F D Pope
- School of Geography , Earth and Environmental Science , University of Birmingham , Edgbaston , B15 2TT , UK .
| | - M K Kuimova
- Department of Chemistry , Imperial College London , London , SW7 2AZ , UK .
| |
Collapse
|
25
|
Acter T, Cho Y, Kim S, Ahmed A, Kim B, Kim S. Optimization and Application of APCI Hydrogen-Deuterium Exchange Mass Spectrometry (HDX MS) for the Speciation of Nitrogen Compounds. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2015; 26:1522-31. [PMID: 26115964 DOI: 10.1007/s13361-015-1166-2] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/10/2015] [Revised: 04/09/2015] [Accepted: 04/10/2015] [Indexed: 05/26/2023]
Abstract
A systematic study was performed to investigate the utility of atmospheric pressure chemical ionization hydrogen-deuterium exchange mass spectrometry (APCI HDX MS) to identify the structures of nitrogen-containing aromatic compounds. First, experiments were performed to determine the optimized experimental conditions, with dichloromethane and CH(3)OD found to be good cosolvents for APCI HDX. In addition, a positive correlation between the heated capillary temperature and the observed HDX signal was observed, and it was suggested that the HDX reaction occurred when molecules were contained in the solvent cluster. Second, 20 standard nitrogen-containing compounds were analyzed to investigate whether speciation could be determined based on the different types of ions produced from nitrogen-containing compounds with various functional groups. The number of exchanges occurring within the compounds correlated well with the number of active hydrogen atoms attached to nitrogen, and it was confirmed that APCI HDX MS could be used to determine speciation. The results obtained by APCI HDX MS were combined with the subsequent investigation of the double bond equivalence distribution and indicated that resins of shale oil extract contained mostly pyridine type nitrogen compounds. This study confirmed that APCI HDX MS can be added to previously reported chemical ionization, electrospray ionization, and atmospheric pressure photo ionization-based HDX methods, which can be used for structural elucidation by mass spectrometry.
Collapse
Affiliation(s)
- Thamina Acter
- Department of Chemistry, Kyungpook National University, Daegu, 702-701, Republic of Korea
| | | | | | | | | | | |
Collapse
|
26
|
Herrmann H, Schaefer T, Tilgner A, Styler SA, Weller C, Teich M, Otto T. Tropospheric aqueous-phase chemistry: kinetics, mechanisms, and its coupling to a changing gas phase. Chem Rev 2015; 115:4259-334. [PMID: 25950643 DOI: 10.1021/cr500447k] [Citation(s) in RCA: 211] [Impact Index Per Article: 23.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Hartmut Herrmann
- Atmospheric Chemistry Department (ACD), Leibniz Institute for Tropospheric Research (TROPOS), Permoserstraße 15, 04318 Leipzig, Germany
| | - Thomas Schaefer
- Atmospheric Chemistry Department (ACD), Leibniz Institute for Tropospheric Research (TROPOS), Permoserstraße 15, 04318 Leipzig, Germany
| | - Andreas Tilgner
- Atmospheric Chemistry Department (ACD), Leibniz Institute for Tropospheric Research (TROPOS), Permoserstraße 15, 04318 Leipzig, Germany
| | - Sarah A Styler
- Atmospheric Chemistry Department (ACD), Leibniz Institute for Tropospheric Research (TROPOS), Permoserstraße 15, 04318 Leipzig, Germany
| | - Christian Weller
- Atmospheric Chemistry Department (ACD), Leibniz Institute for Tropospheric Research (TROPOS), Permoserstraße 15, 04318 Leipzig, Germany
| | - Monique Teich
- Atmospheric Chemistry Department (ACD), Leibniz Institute for Tropospheric Research (TROPOS), Permoserstraße 15, 04318 Leipzig, Germany
| | - Tobias Otto
- Atmospheric Chemistry Department (ACD), Leibniz Institute for Tropospheric Research (TROPOS), Permoserstraße 15, 04318 Leipzig, Germany
| |
Collapse
|
27
|
Methods for characterization of organic compounds in atmospheric aerosol particles. Anal Bioanal Chem 2014; 407:5877-97. [DOI: 10.1007/s00216-014-8394-3] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2014] [Revised: 11/26/2014] [Accepted: 12/05/2014] [Indexed: 10/24/2022]
|
28
|
Romonosky DE, Laskin A, Laskin J, Nizkorodov SA. High-Resolution Mass Spectrometry and Molecular Characterization of Aqueous Photochemistry Products of Common Types of Secondary Organic Aerosols. J Phys Chem A 2014; 119:2594-606. [DOI: 10.1021/jp509476r] [Citation(s) in RCA: 54] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
- Dian E. Romonosky
- Department
of Chemistry, University of California, Irvine, California 92697, United States
| | | | | | - Sergey A. Nizkorodov
- Department
of Chemistry, University of California, Irvine, California 92697, United States
| |
Collapse
|
29
|
Olariu RI, Vione D, Grinberg N, Arsene C. Applications of Liquid Chromatographic Techniques in the Chemical Characterization of Atmospheric Aerosols. J LIQ CHROMATOGR R T 2014. [DOI: 10.1080/10826076.2014.941256] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Affiliation(s)
- Romeo-Iulian Olariu
- a Department of Chemistry, Faculty of Chemistry, Laboratory of Analytical Chemistry , “Alexandru Ioan Cuza” University of Iasi , Iasi , Romania
| | - Davide Vione
- b Dipartimento di Chimica , Università di Torino , Torino , Italy
| | - Nelu Grinberg
- c Boehringer Ingelheim Pharmaceuticals Inc. , Ridgefield , Connecticut , USA
| | - Cecilia Arsene
- a Department of Chemistry, Faculty of Chemistry, Laboratory of Analytical Chemistry , “Alexandru Ioan Cuza” University of Iasi , Iasi , Romania
| |
Collapse
|
30
|
Kidd C, Perraud V, Wingen LM, Finlayson-Pitts BJ. Integrating phase and composition of secondary organic aerosol from the ozonolysis of α-pinene. Proc Natl Acad Sci U S A 2014; 111:7552-7. [PMID: 24821796 PMCID: PMC4040618 DOI: 10.1073/pnas.1322558111] [Citation(s) in RCA: 63] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Airborne particles are important for public health, visibility, and climate. Predicting their concentrations, effects, and responses to control strategies requires accurate models of their formation and growth in air. This is challenging, as a large fraction is formed by complex reactions of volatile organic compounds, generating secondary organic aerosol (SOA), which grows to sizes important for visibility, climate, and deposition in the lung. Growth of SOA is particularly sensitive to the phase/viscosity of the particles and remains poorly understood. We report studies using a custom-designed impactor with a germanium crystal as the impaction surface to study SOA formed from the ozonolysis of α-pinene at relative humidities (RHs) up to 87% at 297 ± 2 K (which corresponds to a maximum RH of 70-86% inside the impactor). The impaction patterns provide insight into changes in phase/viscosity as a function of RH. Attenuated total reflectance-Fourier transform infrared spectroscopy and aerosol mass spectrometry provide simultaneous information on composition changes with RH. The results show that as the RH at which the SOA is formed increases, there is a decrease in viscosity, accompanied by an increasing contribution from carboxylic acids and a decreasing contribution from higher molecular mass products. In contrast, SOA that is formed dry and subsequently humidified remains solid to high RH. The results of these studies have significant implications for modeling the growth, aging, and ultimately, lifetime of SOA in the atmosphere.
Collapse
Affiliation(s)
- Carla Kidd
- Department of Chemistry, University of California, Irvine, CA 92697
| | | | - Lisa M Wingen
- Department of Chemistry, University of California, Irvine, CA 92697
| | | |
Collapse
|
31
|
Kahnt A, Iinuma Y, Blockhuys F, Mutzel A, Vermeylen R, Kleindienst TE, Jaoui M, Offenberg JH, Lewandowski M, Böge O, Herrmann H, Maenhaut W, Claeys M. 2-hydroxyterpenylic acid: an oxygenated marker compound for α-pinene secondary organic aerosol in ambient fine aerosol. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2014; 48:4901-8. [PMID: 24697354 DOI: 10.1021/es500377d] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
An oxygenated MW 188 compound is commonly observed in substantial abundance in atmospheric aerosol samples and was proposed in previous studies as an α-pinene-related marker compound that is associated with aging processes. Owing to difficulties in producing this compound in sufficient amounts in laboratory studies and the occurrence of isobaric isomers, a complete assignment for individual MW 188 compounds could not be achieved in these studies. Results from a comprehensive mass spectrometric analysis are presented here to corroborate the proposed structure of the most abundant MW 188 compound as a 2-hydroxyterpenylic acid diastereoisomer with 2R,3R configuration. The application of collision-induced dissociation with liquid chromatography/electrospray ionization-ion trap mass spectrometry in both negative and positive ion modes, as well as chemical derivatization to methyl ester derivatives and analysis by the latter technique and gas chromatography/electron ionization mass spectrometry, enabled a comprehensive characterization of MW 188 isomers, including a detailed study of the fragmentation behavior using both mass spectrometric techniques. Furthermore, a MW 188 positional isomer, 4-hydroxyterpenylic acid, was tentatively identified, which also is of atmospheric relevance as it could be detected in ambient fine aerosol. Quantum chemical calculations were performed to support the diastereoisomeric assignment of the 2-hydroxyterpenylic acid isomers. Results from a time-resolved α-pinene photooxidation experiment show that the 2-hydroxyterpenylic acid 2R,3R diastereoisomer has a time profile distinctly different from that of 3-methyl-1,2,3-butanetricarboxylic acid, a marker for oxygenated (aged) secondary organic aerosol. This study presents a comprehensive chemical data set for a more complete structural characterization of hydroxyterpenylic acids in ambient fine aerosol, which sets the foundation to better understand the atmospheric fate of α-pinene in future studies.
Collapse
Affiliation(s)
- Ariane Kahnt
- Department of Pharmaceutical Sciences and §Department of Chemistry, University of Antwerp , Campus Drie Eiken, BE 2610 Antwerp, Belgium
| | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
32
|
Zheng G, He K, Duan F, Cheng Y, Ma Y. Measurement of humic-like substances in aerosols: a review. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2013; 181:301-14. [PMID: 23830737 DOI: 10.1016/j.envpol.2013.05.055] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/29/2013] [Revised: 05/30/2013] [Accepted: 05/31/2013] [Indexed: 05/20/2023]
Abstract
Aerosol-phase humic-like substances (HULIS) have received increasingly attention due to their universal ambient presence, active participation in atmospheric chemistry and important environmental and health effects. In last decade, intensive field works have promoted development of quantification and analysis method, unearthed spatio-temporal variation, and proved evidence for source identification of HULIS. These important developments were summarized in this review to provide a global perspective of HULIS. The diverse operational HULIS definitions were gradually focused onto several versions. Although found globally in Europe, Asia, Australasia and North America, HULIS are far more typical in continental and near-ground aerosols. HULIS concentrations varied from <1 μg/m(3) to >13 μg/m(3), with their carbon fraction making up 9%-72% of water soluble organic carbon. Dominant HULIS source was suggested as secondary processes and biomass burning, with the detailed formation pathways suggested and verified in laboratory works.
Collapse
Affiliation(s)
- Guangjie Zheng
- State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, People's Republic of China
| | | | | | | | | |
Collapse
|
33
|
Lee HJJ, Laskin A, Laskin J, Nizkorodov SA. Excitation-emission spectra and fluorescence quantum yields for fresh and aged biogenic secondary organic aerosols. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2013; 47:5763-5770. [PMID: 23663151 DOI: 10.1021/es400644c] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Certain biogenic secondary organic aerosols (SOA) become absorbent and fluorescent when exposed to reduced nitrogen compounds such as ammonia, amines, and their salts. Fluorescent SOA may potentially be mistaken for biological particles by detection methods relying on fluorescence. This work quantifies the spectral distribution and effective quantum yields of fluorescence of water-soluble SOA generated from two monoterpenes, limonene and α-pinene, and two different oxidants, ozone (O3) and hydroxyl radical (OH). The SOA was generated in a smog chamber, collected on substrates, and aged by exposure to ∼100 ppb ammonia in air saturated with water vapor. Absorption and excitation-emission matrix (EEM) spectra of aqueous extracts of aged and control SOA samples were measured, and the effective absorption coefficients and fluorescence quantum yields (∼0.005 for 349 nm excitation) were determined from the data. The strongest fluorescence for the limonene-derived SOA was observed for λexcitation = 420 ± 50 nm and λemission = 475 ± 38 nm. The window of the strongest fluorescence shifted to λexcitation = 320 ± 25 nm and λemission = 425 ± 38 nm for the α-pinene-derived SOA. Both regions overlap with the EEM spectra of some of the fluorophores found in primary biological aerosols. Despite the low quantum yield, the aged SOA particles may have sufficient fluorescence intensities to interfere with the fluorescence detection of common bioaerosols.
Collapse
Affiliation(s)
- Hyun Ji Julie Lee
- Department of Chemistry, University of California, Irvine, California 92697, United States
| | | | | | | |
Collapse
|
34
|
Kourtchev I, Fuller S, Aalto J, Ruuskanen TM, McLeod MW, Maenhaut W, Jones R, Kulmala M, Kalberer M. Molecular composition of boreal forest aerosol from Hyytiälä, Finland, using ultrahigh resolution mass spectrometry. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2013; 47:4069-4079. [PMID: 23469832 DOI: 10.1021/es3051636] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Organic compounds are important constituents of fine particulate matter (PM) in the troposphere. In this study, we applied direct infusion nanoelectrospray (nanoESI) ultrahigh resolution mass spectrometry (UHR-MS) and liquid chromatography LC/ESI-UHR-MS for the analysis of the organic fraction of PM1 aerosol samples collected over a two week period at a boreal forest site (Hyytiälä), southern Finland. Elemental formulas (460-730 in total) were identified with nanoESI-UHR-MS in the negative ionization mode and attributed to organic compounds with a molecular weight below 400. Kendrick Mass Defect and Van Krevelen approaches were used to identify compound classes and mass distributions of the detected species. The molecular composition of the aerosols strongly varied between samples with different air mass histories. An increased number of nitrogen, sulfur, and highly oxygenated organic compounds was observed during the days associated with continental air masses. However, the samples with Atlantic air mass history were marked by a presence of homologous series of unsaturated and saturated C12-C20 fatty acids suggesting their marine origin. To our knowledge, we show for the first time that the highly detailed chemical composition obtained from UHR-MS analyses can be clearly linked to meteorological parameters and trace gases concentrations that are relevant to atmospheric oxidation processes. The additional LC/ESI-UHR-MS analysis revealed 29 species, which were mainly attributed to oxidation products of biogenic volatile compounds BVOCs (i.e., α,β-pinene, Δ3-carene, limonene, and isoprene) supporting the results from the direct infusion analysis.
Collapse
Affiliation(s)
- Ivan Kourtchev
- Department of Chemistry, University of Cambridge, Cambridge CB2 1EW, UK.
| | | | | | | | | | | | | | | | | |
Collapse
|
35
|
Witkowski B, Gierczak T. Analysis of α-acyloxyhydroperoxy aldehydes with electrospray ionization-tandem mass spectrometry (ESI-MS(n)). JOURNAL OF MASS SPECTROMETRY : JMS 2013; 48:79-88. [PMID: 23303750 DOI: 10.1002/jms.3130] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/23/2012] [Revised: 10/17/2012] [Accepted: 10/18/2012] [Indexed: 06/01/2023]
Abstract
A series of α-acyloxyhydroperoxy aldehydes was analyzed with direct infusion electrospray ionization tandem mass spectrometry (ESI/MS(n)) as well as liquid chromatography coupled with the mass spectrometry (LC/MS). Standards of α-acyloxyhydroperoxy aldehydes were prepared by liquid-phase ozonolysis of cyclohexene in the presence of carboxylic acids. Stabilized Criegee intermediate (SCI), a by-product of the ozone attack on the cyclohexene double bond, reacted with the selected carboxylic acids (SCI scavengers) leading to the formation of α-acyloxyhydroperoxy aldehydes. Ionization conditions were optimized. [M + H](+) ions were not formed in ESI; consequently, α-acyloxyhydroperoxy aldehydes were identified as their ammonia adducts for the first time. On the other hand, atmospheric-pressure chemical ionization has led to decomposition of the compounds of interest. Analysis of the mass spectra (MS(2) and MS(3)) of the [M + NH(4)](+) ions allowed recognizing the fragmentation pathways, common for all of the compounds under study. In order to get detailed insights into the fragmentation mechanism, a number of isotopically labeled analogs were also studied. To confirm that the fragmentation mechanism allows predicting the mass spectrum of different α-acyloxyhydroperoxy aldehydes, ozonolysis of α-pinene, a very important secondary organic aerosol precursor, was carried out. Spectra of the two ammonium cationized α-acyloxyhydroperoxy aldehydes prepared with α-pinene, cis-pinonic acid as well as pinic acid were predicted very accurately. Possible applications of the method developed for the analysis of α-acyloxyhydroperoxy aldehydes in SOA samples, as well as other compounds containing hydroperoxide moiety are discussed.
Collapse
Affiliation(s)
- Bartłomiej Witkowski
- Faculty of Chemistry, University of Warsaw, al. Żwirki i Wigury 101, 02-089, Warsaw, Poland
| | | |
Collapse
|
36
|
Tracers for Biogenic Secondary Organic Aerosol from α-Pinene and Related Monoterpenes: An Overview. ACTA ACUST UNITED AC 2012. [DOI: 10.1007/978-94-007-5034-0_18] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/21/2023]
|
37
|
Kilgour DPA, Mackay CL, Langridge-Smith PRR, O'Connor PB. Appropriate degree of trust: deriving confidence metrics for automatic peak assignment in high-resolution mass spectrometry. Anal Chem 2012; 84:7431-5. [PMID: 22880549 DOI: 10.1021/ac301339d] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Techniques for deriving confidence metrics for the reliability of automatically assigned elemental formulas in complex spectra, from high-resolution mass spectrometers, are described. These metrics can help an analyst to place an appropriate degree of trust in the results obtained from automated spectral analysis of, for example, natural organic materials. To provide these metrics of confidence, common mass spectrometric tests for reliability of peak assignment (mass accuracy/error, relative ion abundance, and rings-plus-double-bonds equivalence) are combined with novel confidence metrics based on the interconnectivity and consistency of a mass difference or mass defect based peak inference network and on the confidence of the initial library matches. These are shown to provide improved peak assignment confidence over manual or simple automatic assignment methods.
Collapse
|
38
|
Bateman AP, Laskin J, Laskin A, Nizkorodov SA. Applications of high-resolution electrospray ionization mass spectrometry to measurements of average oxygen to carbon ratios in secondary organic aerosols. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2012; 46:8315-8324. [PMID: 22747310 DOI: 10.1021/es3017254] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
The applicability of high-resolution electrospray ionization mass spectrometry (HR ESI-MS) to measurements of the average oxygen to carbon ratio (O/C) in secondary organic aerosols (SOAs) was investigated. Solutions with known average O/C containing up to 10 standard compounds representative of low-molecular-weight SOA constituents were analyzed and the corresponding electrospray ionization efficiencies were quantified. The assumption of equal ionization efficiency commonly used in estimating O/C ratios of SOAs was found to be reasonably accurate. We found that the accuracy of the measured O/C ratios increases by averaging the values obtained from both the posive and negative modes. A correlation was found between the ratio of the ionization efficiencies in the positive (+) and negative (-) ESI modes and the octanol-water partition constant and, more importantly, the compound's O/C. To demonstrate the utility of this correlation for estimating average O/C values of unknown mixtures, we analyzed the ESI (+) and ESI (-) data for SOAs produced by oxidation of limonene and isoprene and compared them online to O/C measurements using an aerosol mass spectrometer (AMS). This work demonstrates that the accuracy of the HR ESI-MS method is comparable to that of the AMS with the added benefit of molecular identification of the aerosol constituents.
Collapse
Affiliation(s)
- Adam P Bateman
- Department of Chemistry, University of California, Irvine, California 92617, USA
| | | | | | | |
Collapse
|
39
|
Images reveal that atmospheric particles can undergo liquid-liquid phase separations. Proc Natl Acad Sci U S A 2012; 109:13188-93. [PMID: 22847443 DOI: 10.1073/pnas.1206414109] [Citation(s) in RCA: 105] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
A large fraction of submicron atmospheric aerosol particles contains both organic material and inorganic salts. As the relative humidity cycles in the atmosphere and the water content of the particles correspondingly changes, these mixed particles can undergo a range of phase transitions, possibly including liquid-liquid phase separation. If liquid-liquid phase separation occurs, the gas-particle partitioning of atmospheric semivolatile organic compounds, the scattering and absorption of solar radiation, and the reactive uptake of gas species on atmospheric particles may be affected, with important implications for climate predictions. The actual occurrence of liquid-liquid phase separation within individual atmospheric particles has been considered uncertain, in large part because of the absence of observations for real-world samples. Here, using optical and fluorescence microscopy, we present images that show the coexistence of two noncrystalline phases for real-world samples collected on multiple days in Atlanta, GA as well as for laboratory-generated samples under simulated atmospheric conditions. These results reveal that atmospheric particles can undergo liquid-liquid phase separations. To explore the implications of these findings, we carried out simulations of the Atlanta urban environment and found that liquid-liquid phase separation can result in increased concentrations of gas-phase NO(3) and N(2)O(5) due to decreased particle uptake of N(2)O(5).
Collapse
|
40
|
Lin P, Rincon AG, Kalberer M, Yu JZ. Elemental composition of HULIS in the Pearl River Delta Region, China: results inferred from positive and negative electrospray high resolution mass spectrometric data. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2012; 46:7454-7462. [PMID: 22702400 DOI: 10.1021/es300285d] [Citation(s) in RCA: 108] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
The HUmic-LIke Substances (HULIS) fraction isolated from aerosol samples collected at a rural location of the Pearl River Delta Region (PRD), China, during the harvest season was analyzed by both positive and negative mode electrospray ionization (ESI) coupled with an ultrahigh resolution mass spectrometer (UHRMS). With the remarkable resolving power and mass accuracy of ESI-UHRMS, thousands of elemental formulas were identified. Formulas detected in the positive (ESI+) and the negative (ESI-) mode complement each other due to differences in the ionization mechanism, and the use of both provides a more complete characterization of HULIS. Compounds composed of C, H, and O atoms were preferentially detected in ESI- by deprotonation, implying their acidic properties. Tandem MS and Kendrick Mass Defect analysis implies that carboxyl groups are abundant in the CHO compounds. This feature is similar to those of natural fulvic acids, but relatively smaller molecular weights are observed in the HULIS samples. A greater number of reduced nitrogen organic compounds were observed in the ESI+ compared to ESI-. Compounds with biomass burning origin including alkaloids, amino acids, and their derivatives are their probable constituents. Sulfur-containing species were dominantly detected in ESI-. The presence of sulfate fragments in the MS/MS spectra of these species and their high O/S ratios implies that they are mainly organosulfates. Organosulfates and nitrooxy-organosulfates were often the most intensive peaks in the ESI- spectra. They are believed to be products of reactive uptake of photooxidation products of reactive volatile organic compounds by acidic sulfate particles. The elemental compositions deduced from the UHRMS analysis confirm the conclusion from our previous study that biomass burning and SOA formation are both important sources of HULIS in the PRD region.
Collapse
Affiliation(s)
- Peng Lin
- Department of Chemistry, Hong Kong University of Science & Technology, Clear Water Bay, Kowloon, Hong Kong, China
| | | | | | | |
Collapse
|
41
|
Fooshee DR, Nguyen TB, Nizkorodov SA, Laskin J, Laskin A, Baldi P. COBRA: a computational brewing application for predicting the molecular composition of organic aerosols. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2012; 46:6048-6055. [PMID: 22568707 PMCID: PMC3385869 DOI: 10.1021/es3003734] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Atmospheric organic aerosols (OA) represent a significant fraction of airborne particulate matter and can impact climate, visibility, and human health. These mixtures are difficult to characterize experimentally due to their complex and dynamic chemical composition. We introduce a novel Computational Brewing Application (COBRA) and apply it to modeling oligomerization chemistry stemming from condensation and addition reactions in OA formed by photooxidation of isoprene. COBRA uses two lists as input: a list of chemical structures comprising the molecular starting pool and a list of rules defining potential reactions between molecules. Reactions are performed iteratively, with products of all previous iterations serving as reactants for the next. The simulation generated thousands of structures in the mass range of 120-500 Da and correctly predicted ∼70% of the individual OA constituents observed by high-resolution mass spectrometry. Select predicted structures were confirmed with tandem mass spectrometry. Esterification was shown to play the most significant role in oligomer formation, with hemiacetal formation less important, and aldol condensation insignificant. COBRA is not limited to atmospheric aerosol chemistry; it should be applicable to the prediction of reaction products in other complex mixtures for which reasonable reaction mechanisms and seed molecules can be supplied by experimental or theoretical methods.
Collapse
Affiliation(s)
- David R. Fooshee
- School of Information and Computer Sciences, University of California, Irvine, CA 92697-3435
| | - Tran B. Nguyen
- Department of Chemistry, University of California, Irvine, CA 92697-2025
| | | | - Julia Laskin
- Chemical and Materials Sciences Division, Pacific Northwest National Laboratory, Richland, Washington 99352, USA
| | - Alexander Laskin
- Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, Richland, Washington 99352, USA
| | - Pierre Baldi
- School of Information and Computer Sciences, University of California, Irvine, CA 92697-3435
| |
Collapse
|
42
|
Hall WA, Johnston MV. Oligomer formation pathways in secondary organic aerosol from MS and MS/MS measurements with high mass accuracy and resolving power. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2012; 23:1097-1108. [PMID: 22476934 DOI: 10.1007/s13361-012-0362-6] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/09/2011] [Revised: 02/07/2012] [Accepted: 02/10/2012] [Indexed: 05/31/2023]
Abstract
Secondary organic aerosol (SOA) is formed when organic molecules react with oxidants in the gas phase to form particulate matter. Recent measurements have shown that more than half of the mass of laboratory-generated SOA consists of high molecular weight oligomeric compounds. In this work, the formation mechanisms of oligomers produced in the laboratory by ozonolysis of α-pinene, an important SOA precursor in ambient air, are studied by MS and MS/MS measurements with high accuracy and resolving power to characterize monomer building blocks and the reactions that couple them together. The distribution of oligomers in an SOA sample is complex, typically yielding over 1000 elemental formulas that can be assigned from an electrospray ionization mass spectrum. Despite this complexity, MS/MS spectra can be found that give strong evidence for specific oligomer formation pathways that have been postulated but not confirmed. These include aldol and gem-diol reactions of carbonyls as well as peroxyhemiacetal formation from hydroperoxides. The strongest evidence for carbonyl reactions is in the formation of hydrated products. Less compelling evidence is found for dehydrated products and secondary ozonide formation. The number of times that a monomer building block is observed as a fragmentation product in the MS/MS spectra is shown to be independent of the monomer vapor pressure, suggesting that oligomer formation is not driven by equilibrium partitioning of a monomer between the gas and particle phases, but rather by reactive uptake where a monomer collides with the particle surface and rapidly forms an oligomer.
Collapse
Affiliation(s)
- Wiley A Hall
- U.S. Department of Agriculture-Agricultural Research Service, San Joaquin Valley Agricultural Center, Parlier, CA, USA
| | | |
Collapse
|
43
|
Lee JWL, Carrascón V, Gallimore PJ, Fuller SJ, Björkegren A, Spring DR, Pope FD, Kalberer M. The effect of humidity on the ozonolysis of unsaturated compounds in aerosol particles. Phys Chem Chem Phys 2012; 14:8023-31. [PMID: 22532101 DOI: 10.1039/c2cp24094g] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Atmospheric aerosol particles are important in many atmospheric processes such as: light scattering, light absorption, and cloud formation. Oxidation reactions continuously change the chemical composition of aerosol particles, especially the organic mass component, which is often the dominant fraction. These ageing processes are poorly understood but are known to significantly affect the cloud formation potential of aerosol particles. In this study we investigate the effect of humidity and ozone on the chemical composition of two model organic aerosol systems: oleic acid and arachidonic acid. These two acids are also compared to maleic acid an aerosol system we have previously studied using the same techniques. The role of relative humidity in the oxidation scheme of the three carboxylic acids is very compound specific. Relative humidity was observed to have a major influence on the oxidation scheme of maleic acid and arachidonic acid, whereas no dependence was observed for the oxidation of oleic acid. In both, maleic acid and arachidonic acid, an evaporation of volatile oxidation products could only be observed when the particle was exposed to high relative humidities. The particle phase has a strong effect on the particle processing and the effect of water on the oxidation processes. Oleic acid is liquid under all conditions at room temperature (dry or elevated humidity, pure or oxidized particle). Thus ozone can easily diffuse into the bulk of the particle irrespective of the oxidation conditions. In addition, water does not influence the oxidation reactions of oleic acid particles, which is partly explained by the structure of oxidation intermediates. The low water solubility of oleic acid and its ozonolysis products limits the effect of water. This is very different for maleic and arachidonic acid, which change their phase from liquid to solid upon oxidation or upon changes in humidity. In a solid particle the reactions of ozone and water with the organic particle are restricted to the particle surface and hence different regimes of reactivity are dictated by particle phase. The potential relevance of these three model systems to mimic ambient atmospheric processes is discussed.
Collapse
Affiliation(s)
- Jason W L Lee
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge, CB2 1EW, UK
| | | | | | | | | | | | | | | |
Collapse
|
44
|
Leclair JP, Collett JL, Mazzoleni LR. Fragmentation analysis of water-soluble atmospheric organic matter using ultrahigh-resolution FT-ICR mass spectrometry. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2012; 46:4312-4322. [PMID: 22435467 DOI: 10.1021/es203509b] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Isolated water-soluble atmospheric organic matter (AOM) analytes extracted from radiation fogwater samples were analyzed using collision induced dissociation with ultrahigh-resolution Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS). Tandem mass analysis was performed on several mass ranges between 100 and 400 Da to characterize the functional groups of AOM species. Compounds containing nitrogen and/or sulfur were targeted because of the high number of oxygen atoms contained in their molecular formulas. Due to the large number of isobaric ions in the precursor isolation ranges, large numbers of product ions resulted from collision induced dissociation. Common neutral losses were assigned by matching the molecular formulas of the expected product ions with the detected product ions within the appropriate mass spectra. Since polar functional groups are expected to affect the hygroscopic properties of aerosols, the losses of H(2)O, CO(2), CH(3)OH, HNO(3), CH(3)NO(3), SO(3), SO(4) and combinations of these were specifically targeted. Among the 421 compounds studied, the most frequently observed neutral losses were CO(2) (54%), H(2)O (43%) and CH(3)OH (40%). HNO(3) losses were observed for 63% of the studied nitrogen containing compounds and 33% of the studied compounds containing both nitrogen and sulfur. SO(3) losses were observed for 85% of the studied sulfur containing compounds and 42% of studied compounds containing both nitrogen and sulfur. A number of molecular formulas matching those of monoterpene ozonolysis SOA were observed; they include organonitrates, organosulfates, and nitroxy-organosulfates. Overall, the results of fragmentation analysis of 400+ individual molecular precursors elucidate the complexity and multifunctional nature of the isolated water-soluble AOM.
Collapse
Affiliation(s)
- Jeffrey P Leclair
- Department of Chemistry, Michigan Technological University, 1400 Townsend Drive, Houghton, Michigan 49931, United States
| | | | | |
Collapse
|
45
|
Pratt KA, Prather KA. Mass spectrometry of atmospheric aerosols--recent developments and applications. Part I: Off-line mass spectrometry techniques. MASS SPECTROMETRY REVIEWS 2012; 31:1-16. [PMID: 21442634 DOI: 10.1002/mas.20322] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/09/2009] [Revised: 08/19/2010] [Accepted: 08/19/2010] [Indexed: 05/30/2023]
Abstract
Many of the significant advances in our understanding of atmospheric particles can be attributed to the application of mass spectrometry. Mass spectrometry provides high sensitivity with a fast response time to probe chemically complex particles. This review focuses on recent developments and applications in the field of mass spectrometry of atmospheric aerosols. In Part I of this two-part review, we concentrate on off-line mass spectrometry techniques, which require sample collection on filters but can provide detailed molecular speciation. In particular, off-line mass spectrometry techniques utilizing tandem mass spectrometry experiments and high resolution mass analyzers provide improved insight into secondary organic aerosol formation and heterogeneous reaction pathways through detailed structural elucidation at the molecular level.
Collapse
Affiliation(s)
- Kerri A Pratt
- Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, CA 92093, USA
| | | |
Collapse
|
46
|
Doezema LA, Longin T, Cody W, Perraud V, Dawson ML, Ezell MJ, Greaves J, Johnson KR, Finlayson-Pitts BJ. Analysis of secondary organic aerosols in air using extractive electrospray ionization mass spectrometry (EESI-MS). RSC Adv 2012. [DOI: 10.1039/c2ra00961g] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
|
47
|
Baduel C, Monge ME, Voisin D, Jaffrezo JL, George C, Haddad IE, Marchand N, D'Anna B. Oxidation of atmospheric humic like substances by ozone: a kinetic and structural analysis approach. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2011; 45:5238-5244. [PMID: 21574573 DOI: 10.1021/es200587z] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
This work explores the heterogeneous reaction between HUmic-LIke Substances (so-called HULIS) and ozone. Genuine atmospheric HULIS were extracted from aerosol samples collected in Chamonix (France) in winter and used in coated flow tube experiments to evaluate heterogeneous uptake of O₃ on such mixtures. The uptake coefficient (γ) was investigated as a function of pH (from 2.5 to 10), O₃ concentration (from 8 to 33 × 10¹¹ molecules cm⁻³), relative humidity (20 to 65%) and photon flux (from 0 to 1.66 × 10¹⁵ photons cm⁻² s⁻¹). Reactive uptake was found to increase in the irradiated experiment with pH, humidity and photon flux. The extract was characterized before and after exposure to O₃ and/or UV light in the attempt to elucidate the effect of the photochemical aging. Carbon content measurements, UV-vis spectroscopy and functional groups analysis revealed a decrease of the UV absorbance as well as of the carbon mass content, while the functionalization rate (COOH and C═O) and therefore the polarity increased during the simulated photochemical exposure.
Collapse
Affiliation(s)
- Christine Baduel
- UJF-Grenoble 1/CNRS, Laboratoire de Glaciologie et Géophysique de l'Environnement (LGGE), UMR 5183, Grenoble, F-38041, France
| | | | | | | | | | | | | | | |
Collapse
|
48
|
Chen Q, Liu Y, Donahue NM, Shilling JE, Martin ST. Particle-phase chemistry of secondary organic material: modeled compared to measured O:C and H:C elemental ratios provide constraints. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2011; 45:4763-4770. [PMID: 21561129 DOI: 10.1021/es104398s] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Chemical mechanisms for the production of secondary organic material (SOM) are developed in focused laboratory studies but widely used in the complex modeling context of the atmosphere. Given this extrapolation, a stringent testing of the mechanisms is important. In addition to particle mass yield as a typical standard for model-measurement comparison, particle composition expressed as O:C and H:C elemental ratios can serve as a higher dimensional constraint. A paradigm for doing so is developed herein for SOM production from a C(5)-C(10)-C(15) terpene sequence, namely isoprene, α-pinene, and β-caryopyhllene. The model MCM-SIMPOL is introduced based on the Master Chemical Mechanism (MCM v3.2) and a group contribution method for vapor pressures (SIMPOL). The O:C and H:C ratios of the SOM are measured using an Aerosol Mass Spectrometer (AMS). Detailed SOM-specific AMS calibrations for the organic contribution to the H(2)O(+) and CO(+) ions indicate that published O:C and H:C ratios for SOM are systematically too low. Overall, the measurement-model gap was small for particle mass yield but significant for particle-average elemental composition. The implication is that a key chemical pathway is missing from the chemical mechanism. The data can be explained by the particle-phase homolytic decomposition of organic hydroperoxides and subsequent alkyl-radical-promoted oligomerization.
Collapse
Affiliation(s)
- Qi Chen
- School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts, USA
| | | | | | | | | |
Collapse
|
49
|
Roach PJ, Laskin J, Laskin A. Higher-order mass defect analysis for mass spectra of complex organic mixtures. Anal Chem 2011; 83:4924-9. [PMID: 21526851 DOI: 10.1021/ac200654j] [Citation(s) in RCA: 73] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Higher-order mass defect analysis is introduced as a unique formula assignment and visualization method for the analysis of complex mass spectra. This approach is an extension of the concepts of Kendrick mass transformation widely used for identification of homologous compounds differing only by a number of base units (e.g., CH(2), H(2), O, CH(2)O, etc.) in complex mixtures. We present an iterative renormalization routine for defining higher-order homologous series and multidimensional clustering of mass spectral features. This approach greatly simplifies visualization of complex mass spectra and increases the number of chemical formulas that can be confidently assigned for given mass accuracy. The potential for using higher-order mass defects for data reduction and visualization is shown. Higher-order mass defect analysis is described and demonstrated through third-order analysis of a deisotoped high-resolution mass spectrum of crude oil containing nearly 13,000 peaks.
Collapse
Affiliation(s)
- Patrick J Roach
- Chemical and Materials Sciences Division, Pacific Northwest National Laboratory, P.O. Box 999, MSIN K8-88, Richland, Washington 99352, USA
| | | | | |
Collapse
|
50
|
Affiliation(s)
- Thorsten Hoffmann
- Institute of Inorganic and Analytical Chemistry, Johannes Gutenberg-University, Mainz, Germany
| | - Ru-Jin Huang
- Institute of Inorganic and Analytical Chemistry, Johannes Gutenberg-University, Mainz, Germany
| | - Markus Kalberer
- Department of Chemistry, University of Cambridge, Cambridge, United Kingdom
| |
Collapse
|