scholarly journals Linking biogenic hydrocarbons to biogenic aerosol in the Borneo rainforest

2013 ◽  
Vol 13 (7) ◽  
pp. 18113-18141
Author(s):  
J. F. Hamilton ◽  
M. R. Alfarra ◽  
N. Robinson ◽  
M. W. Ward ◽  
A. C. Lewis ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
High Resolution ◽  
Tropical Rainforest ◽  
Ion Trap ◽  
High Resolution Mass Spectrometry ◽  
Organic Aerosol ◽  
Oxidation Products ◽  
Ion Cyclotron Resonance ◽  
Aerosol Formation ◽  
Chemical Structures

Abstract. Emissions of biogenic volatile organic compounds are though to contribute significantly to secondary organic aerosol formation in the tropics, but understanding the process of these transformations has proved difficult, due to the complexity of the chemistry involved and very low concentrations. Aerosols from above a South East Asian tropical rainforest in Borneo were characterised using liquid chromatography-ion trap mass spectrometry, high resolution aerosol mass spectrometry and fourier transform ion cyclotron resonance mass spectrometry (FTICRMS) techniques. Oxygenated compounds were identified in ambient organic aerosol that could be directly traced back to isoprene, monoterpenes and sesquiterpene emissions, by combining field data on chemical structures with mass spectral data generated from synthetically produced products created in a simulation chamber. Eighteen oxygenated species of biogenic origin were identified in the rainforest aerosol from the precursors isoprene, α-pinene, limonene, α-terpinene and β-caryophyllene. The observations provide the unambiguous field detection of monoterpene and sesquiterpene oxidation products in SOA above a pristine tropical rainforest. The presence of 2-methyltetrol organosulfates and an associated sulfated dimer provides direct evidence that isoprene in the presence of sulfate aerosol can make a contribution to biogenic organic aerosol above tropical forests. High-resolution mass spectrometry indicates that sulfur can also be incorporated into oxidation products arising from monoterpene precursors in tropical aerosol.

scholarly journals Linking biogenic hydrocarbons to biogenic aerosol in the Borneo rainforest

2013 ◽  
Vol 13 (22) ◽  
pp. 11295-11305 ◽  
Author(s):  
J. F. Hamilton ◽  
M. R. Alfarra ◽  
N. Robinson ◽  
M. W. Ward ◽  
A. C. Lewis ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
High Resolution ◽  
Tropical Rainforest ◽  
Ion Trap ◽  
High Resolution Mass Spectrometry ◽  
Organic Aerosol ◽  
Oxidation Products ◽  
Ion Cyclotron Resonance ◽  
Aerosol Formation ◽  
Chemical Structures

Abstract. Emissions of biogenic volatile organic compounds are though to contribute significantly to secondary organic aerosol formation in the tropics, but understanding these transformation processes has proved difficult, due to the complexity of the chemistry involved and very low concentrations. Aerosols from above a Southeast Asian tropical rainforest in Borneo were characterised using liquid chromatography–ion trap mass spectrometry, high-resolution aerosol mass spectrometry and Fourier transform ion cyclotron resonance mass spectrometry (FTICRMS) techniques. Oxygenated compounds were identified in ambient organic aerosol that could be directly traced back to isoprene, monoterpenes and sesquiterpene emissions, by combining field data on chemical structures with mass spectral data generated from synthetically produced products created in a simulation chamber. Eighteen oxygenated species of biogenic origin were identified in the rainforest aerosol from the precursors isoprene, α-pinene, limonene, α-terpinene and β-caryophyllene. The observations provide the unambiguous field detection of monoterpene and sesquiterpene oxidation products in SOA above a pristine tropical rainforest. The presence of 2-methyl tetrol organosulfates and an associated sulfated dimer provides direct evidence that isoprene in the presence of sulfate aerosol can make a contribution to biogenic organic aerosol above tropical forests. High-resolution mass spectrometry indicates that sulfur can also be incorporated into oxidation products arising from monoterpene precursors in tropical aerosol.

scholarly journals Investigating the composition of organic aerosol resulting from cyclohexene ozonolysis: low molecular weight and heterogeneous reaction products

2006 ◽  
Vol 6 (12) ◽  
pp. 4973-4984 ◽  
Author(s):  
J. F. Hamilton ◽  
A. C. Lewis ◽  
J. C. Reynolds ◽  
L. J. Carpenter ◽  
A. Lubben
Keyword(s):  
Mass Spectrometry ◽  
Gas Phase ◽  
Ion Trap ◽  
High Resolution Mass Spectrometry ◽  
Heterogeneous Reaction ◽  
Organic Aerosol ◽  
Tandem Mass ◽  
Phase Reaction ◽  
Reaction Products ◽  
Aerosol Formation

Abstract. The composition of organic aerosol formed from the gas phase ozonolysis of cyclohexene has been investigated in a smog chamber experiment. Comprehensive gas chromatography with time of flight mass spectrometric detection was used to determine that dicarboxylic acids and corresponding cyclic anhydrides dominated the small gas phase reaction products found in aerosol sampled during the first hour after initial aerosol formation. Structural analysis of larger more polar molecules was performed using liquid chromatography with ion trap tandem mass spectrometry. This indicated that the majority of identified organic mass was in dimer form, built up from combinations of the most abundant small acid molecules, with frequent indication of the inclusion of adipic acid. Trimers and tetramers potentially formed via similar acid combinations were also observed in lower abundances. Tandem mass spectral data indicated dimers with either acid anhydride or ester functionalities as the linkage between monomers. High-resolution mass spectrometry identified the molecular formulae of the most abundant dimer species to be C10H16O6, C11H18O6, C10H14O8 and C11H16O8 and could be used in some cases to reduce uncertainty in exact chemical structure determination by tandem MS.

scholarly journals Investigating the composition of organic aerosol resulting from cyclohexene ozonolysis: low molecular weight and heterogeneous reaction products

2006 ◽  
Vol 6 (4) ◽  
pp. 6369-6399
Author(s):  
J. F. Hamilton ◽  
A. C. Lewis ◽  
J. Reynolds ◽  
L. J. Carpenter ◽  
A. Lubben
Keyword(s):  
Mass Spectrometry ◽  
Gas Phase ◽  
Ion Trap ◽  
High Resolution Mass Spectrometry ◽  
Heterogeneous Reaction ◽  
Organic Aerosol ◽  
Tandem Mass ◽  
Phase Reaction ◽  
Reaction Products ◽  
Aerosol Formation

Abstract. The composition of organic aerosol formed from the gas phase ozonolysis of cyclohexene has been investigated in a smog chamber experiment. Comprehensive gas chromatography with time of flight mass spectrometric detection was used to determine that dicarboxylic acids and corresponding cyclic anhydrides dominated the small gas phase reaction products found in aerosol sampled during the first hour after initial aerosol formation. Structural analysis of larger more polar molecules was performed using liquid chromatography with ion trap tandem mass spectrometry. This indicated that the majority of identified organic mass was in dimer form, built up from combinations of the most abundant small acid molecules, with frequent indication of the inclusion of adipic acid. Trimers and tetramers potentially formed via similar acid combinations were also observed in lower abundances. Tandem mass spectral data indicated dimers with either acid anhydride or ester functionalities as the linkage between monomers. High-resolution mass spectrometry identified the molecular formulae of the most abundant dimer species to be C10H16O6, C11H18O6, C10H14O8 and C11H16O8 and could be used in some cases to reduce uncertainty in exact chemical structure determination by tandem MS.

scholarly journals Strong anthropogenic control of secondary organic aerosol formation from isoprene in Beijing

2019 ◽  
Author(s):  
Daniel J. Bryant ◽  
William J. Dixon ◽  
James R. Hopkins ◽  
Rachel E. Dunmore ◽  
Kelly L. Pereira ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Urban Areas ◽  
Secondary Organic Aerosol ◽  
Matrix Effects ◽  
High Resolution Mass Spectrometry ◽  
Organic Aerosol ◽  
Oxidation Products ◽  
No Oxidation ◽  
Aerosol Formation ◽  
Anthropogenic Pollutants

Abstract. Isoprene-derived secondary organic aerosol (iSOA) is a significant contributor to organic carbon (OC) in some forested regions, such as tropical rainforests and the Southeast US. However, its contribution to organic aerosol in urban areas, with high levels of anthropogenic pollutants, is poorly understood. In this study we examined the formation of anthropogenic-influenced iSOA during summer in Beijing, China. Local isoprene emissions and high levels of anthropogenic pollutants, in particular NOx and particulate SO42−, led to the formation of iSOA under both high- and low-NO oxidation conditions, with significant heterogeneous transformations of isoprene-derived oxidation products to particulate organosulfates (OSs) and nitrooxy-organosulfates (NOSs). Ultra-pressure liquid chromatography coupled to high-resolution mass spectrometry was combined with a rapid automated data processing technique to quantify 31 proposed iSOA tracers in offline PM2.5 filter extracts. The co-elution of the inorganic ions in the extracts caused matrix effects that impacted two authentic standards differently. The average concentration of iSOA OSs and NOSs was 82.5 ng m−3, around three times higher than the observed concentrations of their oxygenated precursors (2-methyltetrols and 2-methylglyceric acid). OS formation was dependant on both photochemistry and sulfate available for reactive uptake as shown by a strong correlation with the product of ozone (O3) and particulate sulfate (SO42−). A greater proportion of high-NO OS products were observed in Beijing compared to previous studies in less polluted environments. The iSOA derived OSs and NOSs represented on average 0.62 % of the oxidised organic aerosol measured by aerosol mass spectrometry, but this increased to ~ 3 % on certain days. These results indicate for the first time that iSOA formation in urban Beijing is strongly controlled by anthropogenic emissions and results in extensive conversion to heterogeneous OS products.

scholarly journals Secondary Organic Aerosol from Atmospheric Photooxidation of Indole

2017 ◽  
Author(s):  
Julia Montoya ◽  
Jeremy R. Horne ◽  
Mallory L. Hinks ◽  
Lauren T. Fleming ◽  
Veronique Perraud ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Air Quality ◽  
Chemical Composition ◽  
High Resolution ◽  
Secondary Organic Aerosol ◽  
High Resolution Mass Spectrometry ◽  
Organic Aerosol ◽  
Scanning Mobility Particle Sizer ◽  
High Resolution Mass ◽  
Resolution Mass

Abstract. Indole is a heterocyclic compound emitted by various plant species under stressed conditions or during flowering events. The formation, optical properties, and chemical composition of secondary organic aerosol (SOA) formed by low-NOx photooxidation of indole were investigated. The SOA yield (1.1 ± 0.3) was estimated from measuring the particle mass concentration with a scanning mobility particle sizer (SMPS) and correcting it for the wall loss effects. The SOA particles were collected on filters and analysed offline with UV-Vis spectrophotometry to measure the mass absorption coefficient (MAC) of the bulk sample. The samples were visibly brown and had MAC values of ~7 m2/g at λ = 300 nm and ~2 m2/g at λ = 400 nm, comparable to strongly absorbing brown carbon emitted from biomass burning. The chemical composition of SOA was examined with several mass spectrometry methods. The direct analysis in real time mass spectrometry (DART-MS) and nanospray desorption electrospray high resolution mass spectrometry (nano-DESI-HRMS) were used to provide information about the overall distribution of SOA compounds. High performance liquid chromatography, coupled to photodiode array spectrophotometry and high resolution mass spectrometry (HPLC-PDA-HRMS) was used to identify chromophoric compounds. Indole derivatives, such as tryptanthrin, indirubin, indigo dye, and indoxyl red were found to contribute significantly to the visible absorption spectrum of indole SOA. The potential effect of indole SOA on air quality was explored with the airshed model, which found elevated concentrations of indole SOA during the afternoon hours contributing considerably to the total organic aerosol under selected scenarios. Because of its high MAC values, indole SOA can contribute to decreased visibility and poor air quality.

scholarly journals Investigating the use of secondary organic aerosol as seed particles in simulation chamber experiments

2011 ◽  
Vol 11 (12) ◽  
pp. 5917-5929 ◽  
Author(s):  
J. F. Hamilton ◽  
M. Rami Alfarra ◽  
K. P. Wyche ◽  
M. W. Ward ◽  
A. C. Lewis ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Secondary Organic Aerosol ◽  
Organic Aerosol ◽  
Oxidation Products ◽  
Ion Cyclotron Resonance ◽  
Photo Oxidation ◽  
Seed Particles ◽  
Aerosol Mass ◽  
Seed Aerosol ◽  
Limonene Oxidation

Abstract. The use of β-caryophyllene secondary organic aerosol particles as seeds for smog chamber simulations has been investigated. A series of experiments were carried out in the Manchester photochemical chamber as part of the Aerosol Coupling in the Earth System (ACES) project to study the effect of seed particles on the formation of secondary organic aerosol (SOA) from limonene photo-oxidation. Rather than use a conventional seed aerosol containing ammonium sulfate or diesel particles, a method was developed to use in-situ chamber generated seed particles from β-caryophyllene photo-oxidation, which were then diluted to a desired mass loading (in this case 4–13 μg m−3). Limonene was then introduced into the chamber and oxidised, with the formation of SOA seen as a growth in the size of oxidised organic seed particles from 150 to 325 nm mean diameter. The effect of the partitioning of limonene oxidation products onto the seed aerosol was assessed using aerosol mass spectrometry during the experiment and the percentage of m/z 44, an indicator of degree of oxidation, increased from around 5 to 8 %. The hygroscopicity of the aerosol also changed, with the growth factor for 200 nm particles increasing from less than 1.05 to 1.25 at 90 % RH. The detailed chemical composition of the limonene SOA could be extracted from the complex β-caryophyllene matrix using two-dimensional gas chromatography (GC × GC) and liquid chromatography coupled to mass spectrometry. High resolution Fourier Transform Ion Cyclotron Resonance Mass Spectrometry (FTICR-MS) was used to determine exact molecular formulae of the seed and the limonene modified aerosol. The average O:C ratio was seen to increase from 0.32 to 0.37 after limonene oxidation products had condensed onto the organic seed.

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