scholarly journals Fast Peroxy Radical Isomerization and OH Recycling in the Reaction of OH Radicals with Dimethyl Sulfide

2019 ◽  
Vol 10 (21) ◽  
pp. 6478-6483 ◽  
Author(s):  
T. Berndt ◽  
W. Scholz ◽  
B. Mentler ◽  
L. Fischer ◽  
E. H. Hoffmann ◽  
...  
Keyword(s):  
Dimethyl Sulfide ◽  
Peroxy Radical ◽  
Oh Radicals

New pathways of the reaction of OH radicals with dimethyl sulfide based on CH3SCH2O2 isomerization

2020 ◽  
Author(s):  
Torsten Berndt ◽  
Wiebke Scholz ◽  
Bernhard Mentler ◽  
Lukas Fischer ◽  
Erik Hans Hoffmann ◽  
...  
Keyword(s):  
Atmospheric Chemistry ◽  
Dimethyl Sulfide ◽  
Peroxy Radical ◽  
Product Formation ◽  
Experimental Investigations ◽  
Oh Radicals ◽  
Atmospheric Conditions ◽  
Free Jet ◽  
Isomerization Process ◽  
Efficient Detection

<p>Dimethyl sulfide (DMS), produced by marine organisms, represents the most abundant, biogenic sulfur emission into the Earth´s atmosphere. The gas-phase degradation of DMS is mainly initiated by the reaction with the OH radical forming first CH<sub>3</sub>SCH<sub>2</sub>O<sub>2</sub> radicals from the dominant H-abstraction channel. A fast CH<sub>3</sub>SCH<sub>2</sub>O<sub>2</sub> isomerization process was proposed as a result of quantum chemical calculations. In the present study, experimental investigations on the product formation from OH + DMS have been conducted in a free-jet flow system at 295 ± 2 K and 1 bar air. Very efficient detection of CH<sub>3</sub>SCH<sub>2</sub>O<sub>2</sub> isomerization products has been achieved by iodide-CI-APi-TOF measurements allowing to run the reaction for close to atmospheric conditions. It is experimentally shown that the CH<sub>3</sub>SCH<sub>2</sub>O<sub>2</sub> radicals undergo a two-step isomerization process finally forming a product consistent with the formula HOOCH<sub>2</sub>SCHO. The isomerization process is accompanied by OH recycling. The rate-limiting first isomerization step, CH<sub>3</sub>SCH<sub>2</sub>O<sub>2</sub> → CH<sub>2</sub>SCH<sub>2</sub>OOH proceeds with k = (0.23 ± 0.12) s<sup>-1</sup> at 295 ± 2 K. Competing bimolecular CH<sub>3</sub>SCH<sub>2</sub>O<sub>2</sub> reactions with NO, HO<sub>2</sub> or RO<sub>2</sub> radicals are less important for trace-gas conditions over the oceans.  Results of atmospheric chemistry simulations demonstrate the predominance (≥95%) of CH<sub>3</sub>SCH<sub>2</sub>O<sub>2</sub> isomerization. The rapid peroxy radical isomerization, not yet considered in models, substantially changes the understanding of DMS´s degradation processes in the atmosphere.</p>

Kinetics and mechanisms of the reaction of OH radicals with dimethyl sulfide

1988 ◽  
Vol 20 (6) ◽  
pp. 415-431 ◽  
Author(s):  
I. Barnes ◽  
V. Bastian ◽  
K. H. Becker
Keyword(s):  
Dimethyl Sulfide ◽  
Oh Radicals

scholarly journals Interfacial photochemistry of biogenic surfactants: a major source of abiotic volatile organic compounds

2017 ◽  
Vol 200 ◽  
pp. 59-74 ◽  
Author(s):  
Martin Brüggemann ◽  
Nathalie Hayeck ◽  
Chloé Bonnineau ◽  
Stéphane Pesce ◽  
Peter A. Alpert ◽  
...  
Keyword(s):  
Atmospheric Chemistry ◽  
Peroxy Radical ◽  
Bulk Water ◽  
Biologically Active ◽  
Radiation Budget ◽  
Cloud Formation ◽  
Oh Radicals ◽  
Aerosol Formation ◽  
Ambient Conditions ◽  
High Biological Activity

Films of biogenic compounds exposed to the atmosphere are ubiquitously found on the surfaces of cloud droplets, aerosol particles, buildings, plants, soils and the ocean. These air/water interfaces host countless amphiphilic compounds concentrated there with respect to in bulk water, leading to a unique chemical environment. Here, photochemical processes at the air/water interface of biofilm-containing solutions were studied, demonstrating abiotic VOC production from authentic biogenic surfactants under ambient conditions. Using a combination of online-APCI-HRMS and PTR-ToF-MS, unsaturated and functionalized VOCs were identified and quantified, giving emission fluxes comparable to previous field and laboratory observations. Interestingly, VOC fluxes increased with the decay of microbial cells in the samples, indicating that cell lysis due to cell death was the main source for surfactants and VOC production. In particular, irradiation of samples containing solely biofilm cells without matrix components exhibited the strongest VOC production upon irradiation. In agreement with previous studies, LC-MS measurements of the liquid phase suggested the presence of fatty acids and known photosensitizers, possibly inducing the observed VOC productionviaperoxy radical chemistry. Up to now, such VOC emissions were directly accounted to high biological activity in surface waters. However, the results obtained suggest that abiotic photochemistry can lead to similar emissions into the atmosphere, especially in less biologically-active regions. Furthermore, chamber experiments suggest that oxidation (O3/OH radicals) of the photochemically-produced VOCs leads to aerosol formation and growth, possibly affecting atmospheric chemistry and climate-related processes, such as cloud formation or the Earth’s radiation budget.

Unraveling the role of additional OH-radicals in the H–Abstraction from Dimethyl sulfide using quantum chemical computations

2020 ◽  
Vol 739 ◽  
pp. 136963 ◽  
Author(s):  
Zoi Salta ◽  
Jacopo Lupi ◽  
Nicola Tasinato ◽  
Vincenzo Barone ◽  
Oscar N. Ventura
Keyword(s):  
Quantum Chemical ◽  
Dimethyl Sulfide ◽  
Oh Radicals ◽  
Quantum Chemical Computations

scholarly journals Quantification of peroxynitric acid and peroxyacyl nitrates using an ethane-based thermal dissociation peroxy radical chemical amplification cavity ring-down spectrometer

2018 ◽  
Vol 11 (7) ◽  
pp. 4109-4127
Author(s):  
Youssef M. Taha ◽  
Matthew T. Saowapon ◽  
Faisal V. Assad ◽  
Connie Z. Ye ◽  
Xining Chen ◽  
...  
Keyword(s):  
Limit Of Detection ◽  
Thermal Dissociation ◽  
Peroxy Radical ◽  
Ambient Air ◽  
Oh Radicals ◽  
Ionization Mass ◽  
Chemical Amplification ◽  
Peroxynitric Acid ◽  
Peroxyacyl Nitrates ◽  
Cavity Ring Down

Abstract. Peroxy and peroxyacyl nitrates (PNs and PANs) are important trace gas constituents of the troposphere which are challenging to quantify by differential thermal dissociation with NO2 detection in polluted (i.e., high-NOx) environments. In this paper, a thermal dissociation peroxy radical chemical amplification cavity ring-down spectrometer (TD-PERCA-CRDS) for sensitive and selective quantification of total peroxynitrates (ΣPN  =  ΣRO2NO2) and of total peroxyacyl nitrates (ΣPAN  =  ΣRC(O)O2NO2) is described. The instrument features multiple detection channels to monitor the NO2 background and the ROx ( =  HO2 + RO2 + ΣRO2) radicals generated by TD of ΣPN and/or ΣPAN. Chemical amplification is achieved through the addition of 0.6 ppm NO and 1.6 % C2H6 to the inlet. The instrument's performance was evaluated using peroxynitric acid (PNA) and peroxyacetic or peroxypropionic nitric anhydride (PAN or PPN) as representative examples of ΣPN and ΣPAN, respectively, whose abundances were verified by iodide chemical ionization mass spectrometry (CIMS). The amplification factor or chain length increases with temperature up to 69 ± 5 and decreases with analyte concentration and relative humidity (RH). At inlet temperatures above 120 and 250 °C, respectively, PNA and ΣPAN fully dissociated, though their TD profiles partially overlap. Furthermore, interference from ozone (O3) was observed at temperatures above 150 °C, rationalized by its partial dissociation to O atoms which react with C2H6 to form C2H5 and OH radicals. Quantification of PNA and ΣPAN in laboratory-generated mixtures containing O3 was achieved by simultaneously monitoring the TD-PERCA responses in multiple parallel CRDS channels set to different temperatures in the 60 to 130 °C range. The (1 s, 2σ) limit of detection (LOD) of TD-PERCA-CRDS is 6.8 pptv for PNA and 2.6 pptv for ΣPAN and significantly lower than TD-CRDS without chemical amplification. The feasibility of TD-PERCA-CRDS for ambient air measurements is discussed.

Rate coefficients for the gas-phase reaction of OH radicals with dimethyl sulfide: temperature and O2partial pressure dependence

2006 ◽  
Vol 8 (6) ◽  
pp. 728-736 ◽  
Author(s):  
Mihaela Albu ◽  
Ian Barnes ◽  
Karl H. Becker ◽  
Iulia Patroescu-Klotz ◽  
Raluca Mocanu ◽  
...  
Keyword(s):  
Gas Phase ◽  
Pressure Dependence ◽  
Dimethyl Sulfide ◽  
Rate Coefficients ◽  
Oh Radicals ◽  
Phase Reaction ◽  
Gas Phase Reaction

The reaction of OH radicals with dimethyl sulfide

1986 ◽  
Vol 18 (8) ◽  
pp. 837-846 ◽  
Author(s):  
Timothy J. Wallington ◽  
Roger Atkinson ◽  
Ernesto C. Tuazon ◽  
Sara M. Aschmann
Keyword(s):  
Dimethyl Sulfide ◽  
Oh Radicals

The atmospheric oxidation mechanism and kinetics of 1,3,5-trimethylbenzene initiated by OH radicals – a theoretical study

2017 ◽  
Vol 41 (18) ◽  
pp. 10259-10271 ◽  
Author(s):  
S. Ponnusamy ◽  
L. Sandhiya ◽  
K. Senthilkumar
Keyword(s):  
Theoretical Study ◽  
Oxidation Mechanism ◽  
Peroxy Radical ◽  
Ring Closure ◽  
Oh Radicals ◽  
Oh Radical ◽  
Radical Ring ◽  
Atmospheric Fate ◽  
Mechanism And Kinetics ◽  
Kinetics Of

The atmospheric fate of 1,3,5-trimethylbenzene is determined by OH-radical addition, and subsequent bicyclic peroxy radical ring closure and ring breaking pathways.

scholarly journals Heterogeneous OH Oxidation of Isoprene Epoxydiol-Derived Organosulfates: Kinetics, Chemistry and Formation of Inorganic Sulfate

2018 ◽  
Author(s):  
Hoi Ki Lam ◽  
Kai Chung Kwong ◽  
Hon Yin Poon ◽  
James F. Davies ◽  
Zhenfa Zhang ◽  
...  
Keyword(s):  
Real Time ◽  
Mass Spectra ◽  
Peroxy Radical ◽  
Oh Radicals ◽  
Reaction Products ◽  
Sulfate Ester ◽  
Ionization Source ◽  
Kinetic Measurements ◽  
Compositional Evolution ◽  
Aerosol Mass

Abstract. Acid-catalyzed multiphase chemistry of epoxydiols formed from isoprene oxidation yields the most abundant organosulfates (i.e., methyltetrol sulfates) detected in atmospheric fine aerosols. This potentially determines the physicochemical properties of fine aerosols in isoprene-rich regions. However, chemical stability of these organosulfates remains unclear. As a result, we investigate the heterogeneous oxidation of aerosols consisting of potassium 3-methyltetrol sulfate ester (C5H11SO7K) by gas-phase hydroxyl (OH) radicals through studying the oxidation kinetics and reaction products at a relative humidity (RH) of 70.8 %. Real-time molecular composition of the aerosols is obtained by using a Direct Analysis in Real Time (DART) ionization source coupled to a high-resolution mass spectrometer. Aerosol mass spectra reveal that 3-methyltetrol sulfate ester can be detected as its anionic form (C5H11SO7−) via direct ionization in the negative ionization mode. Kinetic measurements reveal that the effective heterogeneous OH rate constant is measured to be 4.74 ± 0.2 × 10−13 cm3 molecule−1 s−1 with a chemical lifetime against OH oxidation of 16.2 ± 0.3 days. Comparison of this lifetime with those against other aerosol removal processes, such as dry and wet deposition, suggests that 3-methyltetrol sulfate ester is likely to be chemically stable over atmospheric timescales. Aerosol mass spectra only show an increase in the intensity of bisulfate ion (HSO4−) after oxidation, suggesting the absence of functionalization processes is likely attributable to the steric effect of substituted functional groups (e.g. methyl, alcohol and sulfate groups) on peroxy–peroxy radical reactions. Overall, potassium 3-methyltetrol sulfate ester likely decomposes to form volatile fragmentation products and aerosol-phase sulfate radial anion (SO4•−). SO4•− subsequently undergoes intermolecular hydrogen abstraction to form HSO4−. These processes appear to explain the compositional evolution of 3-methyltetrol sulfate ester during heterogeneous OH oxidation.

scholarly journals Quantification of peroxynitric acid and peroxyacyl nitrates using an ethane-based thermal dissociation peroxy radical chemical amplification cavity ring-down spectrometer

2018 ◽  
Author(s):  
Youssef M. Taha ◽  
Matthew T. Saowapon ◽  
Faisal V. Assad ◽  
Connie Z. Ye ◽  
Xining Chen ◽  
...  
Keyword(s):  
Limit Of Detection ◽  
Thermal Dissociation ◽  
Peroxy Radical ◽  
Ambient Air ◽  
Oh Radicals ◽  
Ionization Mass ◽  
Chemical Amplification ◽  
Peroxynitric Acid ◽  
Peroxyacyl Nitrates ◽  
Cavity Ring Down

Abstract. Peroxy and peroxyacyl nitrates (PNs and PANs) are important trace gas constituents of the troposphere which are challenging to quantify by differential thermal dissociation with NO2 detection in polluted (i.e., high-NOx) environments. In this paper, a thermal dissociation peroxy radical chemical amplification cavity ring-down spectrometer (TD-PERCA-CRDS) for sensitive and selective quantification of total peroxynitrates (ΣPN = ΣRO2NO2) and of total peroxyacyl nitrates (ΣPAN = ΣRC(O)O2NO2) is described. The instrument features multiple detection channels to monitor the NO2 background and the ROx (= HO2 + RO2 + ΣRO2) radicals generated by TD of ΣPN and/or ΣPAN. Chemical amplification is achieved through addition of 0.6 ppm NO and 1.6 % C2H6 to the inlet. The instrument's performance was evaluated using peroxynitric acid (PNA) and peroxyacetic or peroxypropionic nitric anhydride (PAN or PPN) as representative examples of ΣPN and ΣPAN, respectively, whose abundances were verified by iodide chemical ionization mass spectrometry (CIMS). The amplification factor or chain length increases with temperature up to 69 ± 5 and decreases with analyte concentration and relative humidity (RH). At inlet temperatures above 120 °C and 250 °C, respectively, PNA and ΣPAN fully dissociated, though their TD profiles partially overlap. Furthermore, interference from ozone (O3) was observed at temperatures above 150 °C, rationalized by its partial dissociation to O atoms which react with C2H6 to form C2H5 and OH radicals. Quantification of PNA and ΣPAN in laboratory-generated mixtures containing O3 was achieved by simultaneously monitoring the TD-PERCA responses in multiple parallel CRDS channels set to different temperatures in the 60 °C to 130 °C range. The (1 s, 1σ) limit of detection (LOD) of TD-PERCA-CRDS is 3.4 pptv for PNA and 1.3 pptv for ΣPAN and significantly lower than TD-CRDS without chemical amplification. The feasibility of TD-PERCA-CRDS for ambient air measurements is discussed.

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