Technical Note: A technique to convert NO<sub>2</sub> to NO<sub>2</sub><sup>−</sup> with S(IV) and its application to measuring nitrate photolysis
<p>Nitrate photolysis is a potentially significant mechanism for “renoxifying” the atmosphere, i.e., converting nitrate into nitrogen oxides – nitrogen dioxide (NO<span class="inline-formula"><sub>2</sub></span>) and nitric oxide (NO) – and nitrous acid (HONO)...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2024-04-01
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| Series: | Atmospheric Chemistry and Physics |
| Online Access: | https://acp.copernicus.org/articles/24/4411/2024/acp-24-4411-2024.pdf |
| _version_ | 1797205780696399872 |
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| author | A. Lieberman J. Picco M. Onder C. Anastasio |
| author_facet | A. Lieberman J. Picco M. Onder C. Anastasio |
| author_sort | A. Lieberman |
| collection | DOAJ |
| description | <p>Nitrate photolysis is a potentially significant mechanism for “renoxifying” the atmosphere, i.e., converting nitrate into nitrogen oxides – nitrogen dioxide (NO<span class="inline-formula"><sub>2</sub></span>) and nitric oxide (NO) – and nitrous acid (HONO). Nitrate photolysis in the environment occurs through two channels which produce (1) NO<span class="inline-formula"><sub>2</sub></span> and hydroxyl radical (<span class="inline-formula"><span class="Radical">⚫</span></span>OH) and (2) nitrite (NO<span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M8" display="inline" overflow="scroll" dspmath="mathml"><mrow><msubsup><mi/><mn mathvariant="normal">2</mn><mo>-</mo></msubsup></mrow></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="9pt" height="16pt" class="svg-formula" dspmath="mathimg" md5hash="d70791633dd6ab2cb9df29e9d6103c2b"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="acp-24-4411-2024-ie00004.svg" width="9pt" height="16pt" src="acp-24-4411-2024-ie00004.png"/></svg:svg></span></span>) and an oxygen atom (O(<span class="inline-formula"><sup>3</sup></span>P)). Although the aqueous quantum yields and photolysis rate constants of both channels have been established, field observations suggest that nitrate photolysis is enhanced in the environment. Laboratory studies investigating these enhancements typically only measure one of the two photo-channels, since measuring both channels generally requires separate analytical methods and instrumentation. However, measuring only one channel makes it difficult to assess whether secondary chemistry is enhancing one channel at the expense of the other or if there is an overall enhancement of nitrate photochemistry. Here, we show that the addition of S(IV), i.e., bisulfite and sulfite, can convert NO<span class="inline-formula"><sub>2</sub></span> to NO<span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M11" display="inline" overflow="scroll" dspmath="mathml"><mrow><msubsup><mi/><mn mathvariant="normal">2</mn><mo>-</mo></msubsup></mrow></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="9pt" height="16pt" class="svg-formula" dspmath="mathimg" md5hash="cf5ab84666d459bfffb5030e23e4ac33"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="acp-24-4411-2024-ie00005.svg" width="9pt" height="16pt" src="acp-24-4411-2024-ie00005.png"/></svg:svg></span></span>, allowing for measurement of both nitrate photolysis channels with the same equipment. By varying the concentration of S(IV) and exploring method parameters, we determine the experimental conditions that quantitatively convert NO<span class="inline-formula"><sub>2</sub></span> and accurately quantify the resulting NO<span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M13" display="inline" overflow="scroll" dspmath="mathml"><mrow><msubsup><mi/><mn mathvariant="normal">2</mn><mo>-</mo></msubsup></mrow></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="9pt" height="16pt" class="svg-formula" dspmath="mathimg" md5hash="f06d32f4d6a551848f21e837fd69c018"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="acp-24-4411-2024-ie00006.svg" width="9pt" height="16pt" src="acp-24-4411-2024-ie00006.png"/></svg:svg></span></span>. We then apply the method to a test case, showing how an <span class="inline-formula"><span class="Radical">⚫</span></span>OH scavenger in solution prevents the oxidation of NO<span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M15" display="inline" overflow="scroll" dspmath="mathml"><mrow><msubsup><mi/><mn mathvariant="normal">2</mn><mo>-</mo></msubsup></mrow></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="9pt" height="16pt" class="svg-formula" dspmath="mathimg" md5hash="605864571c3dcb0b6e3cb32dc4ee1961"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="acp-24-4411-2024-ie00007.svg" width="9pt" height="16pt" src="acp-24-4411-2024-ie00007.png"/></svg:svg></span></span> to NO<span class="inline-formula"><sub>2</sub></span> but does not enhance the overall photolysis efficiency of nitrate.</p> |
| first_indexed | 2024-04-24T08:56:34Z |
| format | Article |
| id | doaj.art-1ebc1aacedfb427fa9985a0b9126fb19 |
| institution | Directory Open Access Journal |
| issn | 1680-7316 1680-7324 |
| language | English |
| last_indexed | 2024-04-24T08:56:34Z |
| publishDate | 2024-04-01 |
| publisher | Copernicus Publications |
| record_format | Article |
| series | Atmospheric Chemistry and Physics |
| spelling | doaj.art-1ebc1aacedfb427fa9985a0b9126fb192024-04-16T07:08:04ZengCopernicus PublicationsAtmospheric Chemistry and Physics1680-73161680-73242024-04-01244411441910.5194/acp-24-4411-2024Technical Note: A technique to convert NO<sub>2</sub> to NO<sub>2</sub><sup>−</sup> with S(IV) and its application to measuring nitrate photolysisA. LiebermanJ. PiccoM. OnderC. Anastasio<p>Nitrate photolysis is a potentially significant mechanism for “renoxifying” the atmosphere, i.e., converting nitrate into nitrogen oxides – nitrogen dioxide (NO<span class="inline-formula"><sub>2</sub></span>) and nitric oxide (NO) – and nitrous acid (HONO). Nitrate photolysis in the environment occurs through two channels which produce (1) NO<span class="inline-formula"><sub>2</sub></span> and hydroxyl radical (<span class="inline-formula"><span class="Radical">⚫</span></span>OH) and (2) nitrite (NO<span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M8" display="inline" overflow="scroll" dspmath="mathml"><mrow><msubsup><mi/><mn mathvariant="normal">2</mn><mo>-</mo></msubsup></mrow></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="9pt" height="16pt" class="svg-formula" dspmath="mathimg" md5hash="d70791633dd6ab2cb9df29e9d6103c2b"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="acp-24-4411-2024-ie00004.svg" width="9pt" height="16pt" src="acp-24-4411-2024-ie00004.png"/></svg:svg></span></span>) and an oxygen atom (O(<span class="inline-formula"><sup>3</sup></span>P)). Although the aqueous quantum yields and photolysis rate constants of both channels have been established, field observations suggest that nitrate photolysis is enhanced in the environment. Laboratory studies investigating these enhancements typically only measure one of the two photo-channels, since measuring both channels generally requires separate analytical methods and instrumentation. However, measuring only one channel makes it difficult to assess whether secondary chemistry is enhancing one channel at the expense of the other or if there is an overall enhancement of nitrate photochemistry. Here, we show that the addition of S(IV), i.e., bisulfite and sulfite, can convert NO<span class="inline-formula"><sub>2</sub></span> to NO<span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M11" display="inline" overflow="scroll" dspmath="mathml"><mrow><msubsup><mi/><mn mathvariant="normal">2</mn><mo>-</mo></msubsup></mrow></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="9pt" height="16pt" class="svg-formula" dspmath="mathimg" md5hash="cf5ab84666d459bfffb5030e23e4ac33"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="acp-24-4411-2024-ie00005.svg" width="9pt" height="16pt" src="acp-24-4411-2024-ie00005.png"/></svg:svg></span></span>, allowing for measurement of both nitrate photolysis channels with the same equipment. By varying the concentration of S(IV) and exploring method parameters, we determine the experimental conditions that quantitatively convert NO<span class="inline-formula"><sub>2</sub></span> and accurately quantify the resulting NO<span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M13" display="inline" overflow="scroll" dspmath="mathml"><mrow><msubsup><mi/><mn mathvariant="normal">2</mn><mo>-</mo></msubsup></mrow></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="9pt" height="16pt" class="svg-formula" dspmath="mathimg" md5hash="f06d32f4d6a551848f21e837fd69c018"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="acp-24-4411-2024-ie00006.svg" width="9pt" height="16pt" src="acp-24-4411-2024-ie00006.png"/></svg:svg></span></span>. We then apply the method to a test case, showing how an <span class="inline-formula"><span class="Radical">⚫</span></span>OH scavenger in solution prevents the oxidation of NO<span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M15" display="inline" overflow="scroll" dspmath="mathml"><mrow><msubsup><mi/><mn mathvariant="normal">2</mn><mo>-</mo></msubsup></mrow></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="9pt" height="16pt" class="svg-formula" dspmath="mathimg" md5hash="605864571c3dcb0b6e3cb32dc4ee1961"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="acp-24-4411-2024-ie00007.svg" width="9pt" height="16pt" src="acp-24-4411-2024-ie00007.png"/></svg:svg></span></span> to NO<span class="inline-formula"><sub>2</sub></span> but does not enhance the overall photolysis efficiency of nitrate.</p>https://acp.copernicus.org/articles/24/4411/2024/acp-24-4411-2024.pdf |
| spellingShingle | A. Lieberman J. Picco M. Onder C. Anastasio Technical Note: A technique to convert NO<sub>2</sub> to NO<sub>2</sub><sup>−</sup> with S(IV) and its application to measuring nitrate photolysis Atmospheric Chemistry and Physics |
| title | Technical Note: A technique to convert NO<sub>2</sub> to NO<sub>2</sub><sup>−</sup> with S(IV) and its application to measuring nitrate photolysis |
| title_full | Technical Note: A technique to convert NO<sub>2</sub> to NO<sub>2</sub><sup>−</sup> with S(IV) and its application to measuring nitrate photolysis |
| title_fullStr | Technical Note: A technique to convert NO<sub>2</sub> to NO<sub>2</sub><sup>−</sup> with S(IV) and its application to measuring nitrate photolysis |
| title_full_unstemmed | Technical Note: A technique to convert NO<sub>2</sub> to NO<sub>2</sub><sup>−</sup> with S(IV) and its application to measuring nitrate photolysis |
| title_short | Technical Note: A technique to convert NO<sub>2</sub> to NO<sub>2</sub><sup>−</sup> with S(IV) and its application to measuring nitrate photolysis |
| title_sort | technical note a technique to convert no sub 2 sub to no sub 2 sub sup sup with s iv and its application to measuring nitrate photolysis |
| url | https://acp.copernicus.org/articles/24/4411/2024/acp-24-4411-2024.pdf |
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