Effect of temperature on the formation of highly oxygenated organic molecules (HOMs) from alpha-pinene ozonolysis

Lauriane L. J. Quéléver, Kasper Kristensen, Louise Normann Jensen, Bernadette Rosati, Ricky Teiwes, Kaspar R. Daellenbach, Otso Peräkylä, Pontus Roldin, Rossana Bossi, Henrik B. Pedersen, Marianne Glasius, Merete Bilde, Mikael Ehn

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Highly oxygenated organic molecules (HOMs) are important contributors to secondary organic aerosol (SOA) and new-particle formation (NPF) in the boreal atmosphere. This newly discovered class of molecules is efficiently formed from atmospheric oxidation of biogenic volatile organic compounds (VOCs), such as monoterpenes, through a process called autoxidation. This process, in which peroxy-radical intermediates isomerize to allow addition of molecular oxygen, is expected to be highly temperature-dependent. Here, we studied the dynamics of HOM formation during a -pinene ozonolysis experiments performed at three different temperatures, 20, 0 and - 15 degrees C, in the Aarhus University Research on Aerosol (AURA) chamber. We found that the HOM formation, under our experimental conditions (50 ppb alpha-pinene and 100 ppb ozone), decreased considerably at lower temperature, with molar yields dropping by around a factor of 50 when experiments were performed at 0 degrees C, compared to 20 degrees C. At -15 degrees C, the HOM signals were already close to the detection limit of the nitrate-based chemical ionization atmospheric pressure interface time-of-flight (CI-APi-TOF) mass spectrometer used for measuring gas-phase HOMs. Surprisingly, comparing spectra measured at 0 and 20 degrees C, ratios between HOMs of different oxidation levels, e.g., the typical HOM products C10H14O7, C10H14O9, and C10H14O11, changed considerably less than the total HOM yields. More oxidized species have undergone more isomerization steps; yet, at lower temperature, they did not decrease more than the less oxidized species. One possible explanation is that the primary rate-limiting steps forming these HOMs occur before the products become oxygenated enough to be detected by our CI-APi-TOF (i.e., typically seven or more oxygen atoms). The strong temperature dependence of HOM formation was observed under temperatures highly relevant to the boreal forest, but the exact magnitude of this effect in the atmosphere will be much more complex: the fate of peroxy radicals is a competition between autoxidation (influenced by temperature and VOC type) and bimolecular termination pathways (influenced mainly by concentration of reaction partners). While the temperature influence is likely smaller in the boreal atmosphere than in our chamber, both the magnitude and complexity of this effect clearly deserve more consideration in future studies in order to estimate the ultimate role of HOMs on SOA and NPF under different atmospheric conditions.
Originalspråkengelska
TidskriftAtmospheric Chemistry and Physics
Volym19
Utgåva11
Sidor (från-till)7609-7625
Antal sidor17
ISSN1680-7316
DOI
StatusPublicerad - 7 jun 2019
MoE-publikationstypA1 Tidskriftsartikel-refererad

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  • 114 Fysik
  • 116 Kemi
  • 1172 Miljövetenskap

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Quéléver, Lauriane L. J. ; Kristensen, Kasper ; Jensen, Louise Normann ; Rosati, Bernadette ; Teiwes, Ricky ; Daellenbach, Kaspar R. ; Peräkylä, Otso ; Roldin, Pontus ; Bossi, Rossana ; Pedersen, Henrik B. ; Glasius, Marianne ; Bilde, Merete ; Ehn, Mikael. / Effect of temperature on the formation of highly oxygenated organic molecules (HOMs) from alpha-pinene ozonolysis. I: Atmospheric Chemistry and Physics. 2019 ; Vol. 19, Nr. 11. s. 7609-7625.
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title = "Effect of temperature on the formation of highly oxygenated organic molecules (HOMs) from alpha-pinene ozonolysis",
abstract = "Highly oxygenated organic molecules (HOMs) are important contributors to secondary organic aerosol (SOA) and new-particle formation (NPF) in the boreal atmosphere. This newly discovered class of molecules is efficiently formed from atmospheric oxidation of biogenic volatile organic compounds (VOCs), such as monoterpenes, through a process called autoxidation. This process, in which peroxy-radical intermediates isomerize to allow addition of molecular oxygen, is expected to be highly temperature-dependent. Here, we studied the dynamics of HOM formation during a -pinene ozonolysis experiments performed at three different temperatures, 20, 0 and - 15 degrees C, in the Aarhus University Research on Aerosol (AURA) chamber. We found that the HOM formation, under our experimental conditions (50 ppb alpha-pinene and 100 ppb ozone), decreased considerably at lower temperature, with molar yields dropping by around a factor of 50 when experiments were performed at 0 degrees C, compared to 20 degrees C. At -15 degrees C, the HOM signals were already close to the detection limit of the nitrate-based chemical ionization atmospheric pressure interface time-of-flight (CI-APi-TOF) mass spectrometer used for measuring gas-phase HOMs. Surprisingly, comparing spectra measured at 0 and 20 degrees C, ratios between HOMs of different oxidation levels, e.g., the typical HOM products C10H14O7, C10H14O9, and C10H14O11, changed considerably less than the total HOM yields. More oxidized species have undergone more isomerization steps; yet, at lower temperature, they did not decrease more than the less oxidized species. One possible explanation is that the primary rate-limiting steps forming these HOMs occur before the products become oxygenated enough to be detected by our CI-APi-TOF (i.e., typically seven or more oxygen atoms). The strong temperature dependence of HOM formation was observed under temperatures highly relevant to the boreal forest, but the exact magnitude of this effect in the atmosphere will be much more complex: the fate of peroxy radicals is a competition between autoxidation (influenced by temperature and VOC type) and bimolecular termination pathways (influenced mainly by concentration of reaction partners). While the temperature influence is likely smaller in the boreal atmosphere than in our chamber, both the magnitude and complexity of this effect clearly deserve more consideration in future studies in order to estimate the ultimate role of HOMs on SOA and NPF under different atmospheric conditions.",
keywords = "OXIDIZED RO2 RADICALS, MASS-SPECTROMETER, TROPOSPHERIC DEGRADATION, AEROSOL, PRODUCTS, AUTOXIDATION, GROWTH, SIZE, MECHANISM, PROTOCOL, 114 Physical sciences, 116 Chemical sciences, 1172 Environmental sciences",
author = "Qu{\'e}l{\'e}ver, {Lauriane L. J.} and Kasper Kristensen and Jensen, {Louise Normann} and Bernadette Rosati and Ricky Teiwes and Daellenbach, {Kaspar R.} and Otso Per{\"a}kyl{\"a} and Pontus Roldin and Rossana Bossi and Pedersen, {Henrik B.} and Marianne Glasius and Merete Bilde and Mikael Ehn",
year = "2019",
month = "6",
day = "7",
doi = "10.5194/acp-19-7609-2019",
language = "English",
volume = "19",
pages = "7609--7625",
journal = "Atmospheric Chemistry and Physics",
issn = "1680-7316",
publisher = "COPERNICUS GESELLSCHAFT MBH",
number = "11",

}

Effect of temperature on the formation of highly oxygenated organic molecules (HOMs) from alpha-pinene ozonolysis. / Quéléver, Lauriane L. J.; Kristensen, Kasper; Jensen, Louise Normann; Rosati, Bernadette; Teiwes, Ricky; Daellenbach, Kaspar R.; Peräkylä, Otso; Roldin, Pontus; Bossi, Rossana; Pedersen, Henrik B.; Glasius, Marianne; Bilde, Merete; Ehn, Mikael.

I: Atmospheric Chemistry and Physics, Vol. 19, Nr. 11, 07.06.2019, s. 7609-7625.

Forskningsoutput: TidskriftsbidragArtikelVetenskapligPeer review

TY - JOUR

T1 - Effect of temperature on the formation of highly oxygenated organic molecules (HOMs) from alpha-pinene ozonolysis

AU - Quéléver, Lauriane L. J.

AU - Kristensen, Kasper

AU - Jensen, Louise Normann

AU - Rosati, Bernadette

AU - Teiwes, Ricky

AU - Daellenbach, Kaspar R.

AU - Peräkylä, Otso

AU - Roldin, Pontus

AU - Bossi, Rossana

AU - Pedersen, Henrik B.

AU - Glasius, Marianne

AU - Bilde, Merete

AU - Ehn, Mikael

PY - 2019/6/7

Y1 - 2019/6/7

N2 - Highly oxygenated organic molecules (HOMs) are important contributors to secondary organic aerosol (SOA) and new-particle formation (NPF) in the boreal atmosphere. This newly discovered class of molecules is efficiently formed from atmospheric oxidation of biogenic volatile organic compounds (VOCs), such as monoterpenes, through a process called autoxidation. This process, in which peroxy-radical intermediates isomerize to allow addition of molecular oxygen, is expected to be highly temperature-dependent. Here, we studied the dynamics of HOM formation during a -pinene ozonolysis experiments performed at three different temperatures, 20, 0 and - 15 degrees C, in the Aarhus University Research on Aerosol (AURA) chamber. We found that the HOM formation, under our experimental conditions (50 ppb alpha-pinene and 100 ppb ozone), decreased considerably at lower temperature, with molar yields dropping by around a factor of 50 when experiments were performed at 0 degrees C, compared to 20 degrees C. At -15 degrees C, the HOM signals were already close to the detection limit of the nitrate-based chemical ionization atmospheric pressure interface time-of-flight (CI-APi-TOF) mass spectrometer used for measuring gas-phase HOMs. Surprisingly, comparing spectra measured at 0 and 20 degrees C, ratios between HOMs of different oxidation levels, e.g., the typical HOM products C10H14O7, C10H14O9, and C10H14O11, changed considerably less than the total HOM yields. More oxidized species have undergone more isomerization steps; yet, at lower temperature, they did not decrease more than the less oxidized species. One possible explanation is that the primary rate-limiting steps forming these HOMs occur before the products become oxygenated enough to be detected by our CI-APi-TOF (i.e., typically seven or more oxygen atoms). The strong temperature dependence of HOM formation was observed under temperatures highly relevant to the boreal forest, but the exact magnitude of this effect in the atmosphere will be much more complex: the fate of peroxy radicals is a competition between autoxidation (influenced by temperature and VOC type) and bimolecular termination pathways (influenced mainly by concentration of reaction partners). While the temperature influence is likely smaller in the boreal atmosphere than in our chamber, both the magnitude and complexity of this effect clearly deserve more consideration in future studies in order to estimate the ultimate role of HOMs on SOA and NPF under different atmospheric conditions.

AB - Highly oxygenated organic molecules (HOMs) are important contributors to secondary organic aerosol (SOA) and new-particle formation (NPF) in the boreal atmosphere. This newly discovered class of molecules is efficiently formed from atmospheric oxidation of biogenic volatile organic compounds (VOCs), such as monoterpenes, through a process called autoxidation. This process, in which peroxy-radical intermediates isomerize to allow addition of molecular oxygen, is expected to be highly temperature-dependent. Here, we studied the dynamics of HOM formation during a -pinene ozonolysis experiments performed at three different temperatures, 20, 0 and - 15 degrees C, in the Aarhus University Research on Aerosol (AURA) chamber. We found that the HOM formation, under our experimental conditions (50 ppb alpha-pinene and 100 ppb ozone), decreased considerably at lower temperature, with molar yields dropping by around a factor of 50 when experiments were performed at 0 degrees C, compared to 20 degrees C. At -15 degrees C, the HOM signals were already close to the detection limit of the nitrate-based chemical ionization atmospheric pressure interface time-of-flight (CI-APi-TOF) mass spectrometer used for measuring gas-phase HOMs. Surprisingly, comparing spectra measured at 0 and 20 degrees C, ratios between HOMs of different oxidation levels, e.g., the typical HOM products C10H14O7, C10H14O9, and C10H14O11, changed considerably less than the total HOM yields. More oxidized species have undergone more isomerization steps; yet, at lower temperature, they did not decrease more than the less oxidized species. One possible explanation is that the primary rate-limiting steps forming these HOMs occur before the products become oxygenated enough to be detected by our CI-APi-TOF (i.e., typically seven or more oxygen atoms). The strong temperature dependence of HOM formation was observed under temperatures highly relevant to the boreal forest, but the exact magnitude of this effect in the atmosphere will be much more complex: the fate of peroxy radicals is a competition between autoxidation (influenced by temperature and VOC type) and bimolecular termination pathways (influenced mainly by concentration of reaction partners). While the temperature influence is likely smaller in the boreal atmosphere than in our chamber, both the magnitude and complexity of this effect clearly deserve more consideration in future studies in order to estimate the ultimate role of HOMs on SOA and NPF under different atmospheric conditions.

KW - OXIDIZED RO2 RADICALS

KW - MASS-SPECTROMETER

KW - TROPOSPHERIC DEGRADATION

KW - AEROSOL

KW - PRODUCTS

KW - AUTOXIDATION

KW - GROWTH

KW - SIZE

KW - MECHANISM

KW - PROTOCOL

KW - 114 Physical sciences

KW - 116 Chemical sciences

KW - 1172 Environmental sciences

U2 - 10.5194/acp-19-7609-2019

DO - 10.5194/acp-19-7609-2019

M3 - Article

VL - 19

SP - 7609

EP - 7625

JO - Atmospheric Chemistry and Physics

JF - Atmospheric Chemistry and Physics

SN - 1680-7316

IS - 11

ER -