Reactive uptake of ammonia to secondary organic aerosols: kinetics of organonitrogen formation

Liu, Y.; Liggio, J.; Staebler, R.; Li, S.-M.

doi:https://doi.org/10.5194/acp-15-13569-2015

Articles | Volume 15, issue 23

https://doi.org/10.5194/acp-15-13569-2015

© Author(s) 2015. This work is distributed under
the Creative Commons Attribution 3.0 License.

https://doi.org/10.5194/acp-15-13569-2015

© Author(s) 2015. This work is distributed under
the Creative Commons Attribution 3.0 License.

Articles | Volume 15, issue 23

Research article

|

09 Dec 2015

Research article |

| 09 Dec 2015

Reactive uptake of ammonia to secondary organic aerosols: kinetics of organonitrogen formation

Y. Liu, J. Liggio, R. Staebler, and S.-M. Li

Download

Final revised paper (published on 09 Dec 2015)
Supplement to the final revised paper
Preprint (discussion started on 25 Jun 2015)
Supplement to the preprint

Interactive discussion

Status: closed

AC: Author comment | RC: Referee comment | SC: Short comment | EC: Editor comment

- Printer-friendly version

- Supplement

RC C4250: 'Review of Liu et al. paper on reactive uptake of NH3 by SOA', Anonymous Referee #1, 02 Jul 2015
- AC C7412: 'Reactive Uptake of Ammonia to Secondary Organic Aerosols: Kinetics of Organonitrogen Formation', Yongchun Liu, 30 Sep 2015
RC C7028: 'Reviewer report', Anonymous Referee #2, 21 Sep 2015
- AC C7425: 'Reactive Uptake of Ammonia to Secondary Organic Aerosols: Kinetics of Organonitrogen Formation', Yongchun Liu, 30 Sep 2015

Peer-review completion

AR: Author's response | RR: Referee report | ED: Editor decision

AR by Yongchun Liu on behalf of the Authors (30 Sep 2015) Author's response Manuscript

ED: Referee Nomination & Report Request started (01 Oct 2015) by Frank Keutsch

RR by Anonymous Referee #1 (15 Oct 2015)

RR by Anonymous Referee #2 (02 Nov 2015)

Suggestions for revision or reasons for rejection

In my initial review, I indicated that their discussions on the mechanism of NH3 on SOA leading to organonitrogen formation was both qualitative and speculative. In their response letter they claimed that “We cannot of course, be fully quantitative in these types of experiments for a variety of reasons. Such reasons include the inability to detect specific product molecules with the AMS, and the potential for other functional groups (ie: acids) to be formed from both precursors with oxidative aging. Regardless, the possible dominance of dicarbonyls in the aromatic system is a plausible reason for the enhanced NOC observed. While this cannot be confirmed we have nonetheless modified the manuscript to reflect this possibility”. They further revised the manuscript to indicate that “As discussed in Section 3.2, a-dicarbonyls are likely the most dominant products from the OH-initiated oxidation of m-xylene (Zhao et al., 2005), while organic acids are more likely the dominant SOA component from ozonolysis of -pinene (Ma et al., 2013). This suggests an efficient reaction for -dicarbonyls with NH3 to form imine and/or imidazole and is consistent with the higher NOC content in the total SOA mass from OH oxidation of m-xylene”. I find that their argument was very confusing here. On what ground did they claim that the reaction of a-dicarbonyls with NH3 to form imine and/or imidazole was more efficient than the acid-base reaction between organic acids and NH3? Also, what was missing here was that the authors would need to provide a detailed account for both reaction types in the literature (see Zhang et al., 2015, Chem. Rev. for a review on heterogeneous reactions), both in the introduction and discussion sections.
Also, I found the manuscript could be benefitted by a more careful editing for its usage of English. A few examples are given below in the abstract, and there are many others throughout the manuscript.
Line 21. “The uptake coefficients of NH3 to SOA leading to organonitrogen compounds are reported for the first time and were in the range of ~10-3-10-2”. Inconsistent tense usage.
Line 33. “NOC from such a mechanism may be an important and unaccounted for source of PM associated nitrogen, and a mechanism for medium or long-range transport and dry/wet deposition of atmospheric nitrogen” is awkward.

Hide

ED: Reconsider after major revisions (09 Nov 2015) by Frank Keutsch

AR by Yongchun Liu on behalf of the Authors (20 Nov 2015) Author's response Manuscript

ED: Publish subject to technical corrections (24 Nov 2015) by Frank Keutsch

AR by Yongchun Liu on behalf of the Authors (25 Nov 2015) Author's response Manuscript

Download

Article (1075 KB)
Full-text XML

Short summary

This work for the first time demonstrated that organonitrogen compounds (NOC) can be formed efficiently via the uptake of ammonia by newly formed secondary organic aerosol using a smog chamber equipped with a HR-ToF-AMS. Based on the measured kinetics, this study suggests that light absorption by NOC in atmospheric particles may be important in regions where the BC contribution is minimal and NOC from ammonia should be considered with respect to overall deposition of nitrogen to ecosystems.