Nitrate radical oxidation of <i>γ</i>-terpinene: hydroxy nitrate, total organic nitrate, and secondary organic aerosol yields
Polyolefinic monoterpenes represent a potentially important but understudied source of organic nitrates (ONs) and secondary organic aerosol (SOA) following oxidation due to their high reactivity and propensity for multi-stage chemistry. Recent modeling work suggests that the oxidation of polyole...
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| Format: | Article |
| Language: | English |
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Copernicus Publications
2017-07-01
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| Series: | Atmospheric Chemistry and Physics |
| Online Access: | https://www.atmos-chem-phys.net/17/8635/2017/acp-17-8635-2017.pdf |
| _version_ | 1818494723809083392 |
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| author | J. H. Slade C. de Perre L. Lee P. B. Shepson P. B. Shepson |
| author_facet | J. H. Slade C. de Perre L. Lee P. B. Shepson P. B. Shepson |
| author_sort | J. H. Slade |
| collection | DOAJ |
| description | Polyolefinic monoterpenes represent a potentially important but understudied
source of organic nitrates (ONs) and secondary organic aerosol (SOA)
following oxidation due to their high reactivity and propensity for
multi-stage chemistry. Recent modeling work suggests that the oxidation of
polyolefinic <i>γ</i>-terpinene can be the dominant source of nighttime ON
in a mixed forest environment. However, the ON yields, aerosol partitioning
behavior, and SOA yields from <i>γ</i>-terpinene oxidation by the nitrate
radical (NO<sub>3</sub>), an important nighttime oxidant, have not been determined
experimentally. In this work, we present a comprehensive experimental
investigation of the total (gas + particle) ON, hydroxy nitrate, and SOA
yields following <i>γ</i>-terpinene oxidation by NO<sub>3</sub>. Under dry
conditions, the hydroxy nitrate yield = 4(+1/−3) %, total ON
yield = 14(+3/−2) %, and SOA yield ≤ 10 % under
atmospherically relevant particle mass loadings, similar to those for <i>α</i>-pinene + NO<sub>3</sub>. Using a chemical box model, we show that the
measured concentrations of NO<sub>2</sub> and <i>γ</i>-terpinene hydroxy nitrates
can be reliably simulated from <i>α</i>-pinene + NO<sub>3</sub> chemistry.
This suggests that NO<sub>3</sub> addition to either of the two internal double
bonds of <i>γ</i>-terpinene primarily decomposes forming a relatively
volatile keto-aldehyde, reconciling the small SOA yield observed here and for
other internal olefinic terpenes. Based on aerosol partitioning analysis and
identification of speciated particle-phase ON applying high-resolution liquid
chromatography–mass spectrometry, we estimate that a significant fraction of
the particle-phase ON has the hydroxy nitrate moiety. This work greatly
contributes to our understanding of ON and SOA formation from polyolefin
monoterpene oxidation, which could be important in the northern continental
US and the Midwest, where polyolefinic monoterpene emissions are greatest. |
| first_indexed | 2024-12-10T18:10:16Z |
| format | Article |
| id | doaj.art-ecf62942ac9b4d70b779089544afe6b0 |
| institution | Directory Open Access Journal |
| issn | 1680-7316 1680-7324 |
| language | English |
| last_indexed | 2024-12-10T18:10:16Z |
| publishDate | 2017-07-01 |
| publisher | Copernicus Publications |
| record_format | Article |
| series | Atmospheric Chemistry and Physics |
| spelling | doaj.art-ecf62942ac9b4d70b779089544afe6b02022-12-22T01:38:30ZengCopernicus PublicationsAtmospheric Chemistry and Physics1680-73161680-73242017-07-01178635865010.5194/acp-17-8635-2017Nitrate radical oxidation of <i>γ</i>-terpinene: hydroxy nitrate, total organic nitrate, and secondary organic aerosol yieldsJ. H. Slade0C. de Perre1L. Lee2P. B. Shepson3P. B. Shepson4Department of Chemistry, Purdue University, West Lafayette, IN 47907, USADepartment of Agronomy, Purdue University, West Lafayette, IN 47907, USADepartment of Agronomy, Purdue University, West Lafayette, IN 47907, USADepartment of Chemistry, Purdue University, West Lafayette, IN 47907, USADepartment of Earth, Atmospheric, and Planetary Sciences, Purdue University, West Lafayette, IN 47907, USAPolyolefinic monoterpenes represent a potentially important but understudied source of organic nitrates (ONs) and secondary organic aerosol (SOA) following oxidation due to their high reactivity and propensity for multi-stage chemistry. Recent modeling work suggests that the oxidation of polyolefinic <i>γ</i>-terpinene can be the dominant source of nighttime ON in a mixed forest environment. However, the ON yields, aerosol partitioning behavior, and SOA yields from <i>γ</i>-terpinene oxidation by the nitrate radical (NO<sub>3</sub>), an important nighttime oxidant, have not been determined experimentally. In this work, we present a comprehensive experimental investigation of the total (gas + particle) ON, hydroxy nitrate, and SOA yields following <i>γ</i>-terpinene oxidation by NO<sub>3</sub>. Under dry conditions, the hydroxy nitrate yield = 4(+1/−3) %, total ON yield = 14(+3/−2) %, and SOA yield ≤ 10 % under atmospherically relevant particle mass loadings, similar to those for <i>α</i>-pinene + NO<sub>3</sub>. Using a chemical box model, we show that the measured concentrations of NO<sub>2</sub> and <i>γ</i>-terpinene hydroxy nitrates can be reliably simulated from <i>α</i>-pinene + NO<sub>3</sub> chemistry. This suggests that NO<sub>3</sub> addition to either of the two internal double bonds of <i>γ</i>-terpinene primarily decomposes forming a relatively volatile keto-aldehyde, reconciling the small SOA yield observed here and for other internal olefinic terpenes. Based on aerosol partitioning analysis and identification of speciated particle-phase ON applying high-resolution liquid chromatography–mass spectrometry, we estimate that a significant fraction of the particle-phase ON has the hydroxy nitrate moiety. This work greatly contributes to our understanding of ON and SOA formation from polyolefin monoterpene oxidation, which could be important in the northern continental US and the Midwest, where polyolefinic monoterpene emissions are greatest.https://www.atmos-chem-phys.net/17/8635/2017/acp-17-8635-2017.pdf |
| spellingShingle | J. H. Slade C. de Perre L. Lee P. B. Shepson P. B. Shepson Nitrate radical oxidation of <i>γ</i>-terpinene: hydroxy nitrate, total organic nitrate, and secondary organic aerosol yields Atmospheric Chemistry and Physics |
| title | Nitrate radical oxidation of <i>γ</i>-terpinene: hydroxy nitrate, total organic nitrate, and secondary organic aerosol yields |
| title_full | Nitrate radical oxidation of <i>γ</i>-terpinene: hydroxy nitrate, total organic nitrate, and secondary organic aerosol yields |
| title_fullStr | Nitrate radical oxidation of <i>γ</i>-terpinene: hydroxy nitrate, total organic nitrate, and secondary organic aerosol yields |
| title_full_unstemmed | Nitrate radical oxidation of <i>γ</i>-terpinene: hydroxy nitrate, total organic nitrate, and secondary organic aerosol yields |
| title_short | Nitrate radical oxidation of <i>γ</i>-terpinene: hydroxy nitrate, total organic nitrate, and secondary organic aerosol yields |
| title_sort | nitrate radical oxidation of i γ i terpinene hydroxy nitrate total organic nitrate and secondary organic aerosol yields |
| url | https://www.atmos-chem-phys.net/17/8635/2017/acp-17-8635-2017.pdf |
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