Please see attached.

Dear Dr Benoit,

Thank you for your swift response and performing additional experiments, which significantly improved your manuscript.

I have a comment on the following statement in your manuscript: 'The RF amplitude is used to define the lower limit of the mass range, its dynamic range (with a maximum value of 15 in the case of the Q Exactive Orbitrap), but also the efficiency with which produced ions are trapped before being injected into the Orbitrap for mass analysis. Thus, we cannot exclude that some new compounds are associated with unrealistic compounds with respect to the atmosphere'.
I think you unintentionally combined responses on two comments into one. The way it can be read now that the RF voltages will impact on observation of atmospherically unrealistic compounds. I assume this is not what you wanted to say. It is highly unlikely that RF voltages can lead to atmospherically unrealistic compounds. Although some MS conditions have shown to lead to formation of environmentally irrelevant compounds (e.g. formation of non-covalent artifacts), these would not be related to RF voltages (please see my second comment below). Atmospherically unrealistic compounds would mainly arise from the laboratory experimental conditions, e.g. use of high concentrations of hydrocarbons in the flow tube vs more atmospherically relevant concentrations used in the chamber experiments (as stated by two reviewers). This needs to be clearly stated in your manuscript and in the right place (e.g. in introductory and conclusion sessions) to address the comment of the two reviewers. I would also add a statement of caution when you compare/consider the molecular composition or chemical evolution from different experiments in your Table 1 (chamber vs flow tube, and different MS instruments).

The use of MS acquisition scan ranges, on the other hand, can affect transmission of ions, especially at the higher mass range (as you clearly demonstrated in your additional experiments that were requested upon review) and thus impacting on presence/observation of e.g. molecular clusters observed e.g. on VK and DBE plots. Therefore this needs to be taken into account when comparing your data with that of literature (as they used different MS detectors, e.g. FTICRMS and/or acquisition parameters). Therefore, the statement in the line 174 'Thus, we cannot exclude that some new compounds are associated with unrealistic compounds with respect to the atmosphere' needs to be replaced with an appropriate statement reflecting the observed phenomenon. It is also worth adding such statement (based on your figure 9S) to the results and discussion section, e.g. ether after the line 237 or 248 indicating the caveat when comparing your results with the literature data or using their data for your interpretation.

In your responses, please indicate the line numbers where your new text/responses was/were added otherwise it is difficult to follow when and how you responded to the reviewers' and editor's comments. Please make sure you respond to all comments from all referees and the editor.

Kind regards,

Ivan Kourtchev

These are the comments to the authors:

Line 25: replace ‘oxygenated products’ with ‘molecular formulae’
Line 40: abbreviation should be done in the first appearance order, so abbreviate VOC in line 40
Line 47: replace ‘α- Pinene’ with ‘α-pinene’
Line 165: delete repeating sentence
Line 177: remove dots after ‘CHO,…)’
Line 178: remove dots after ‘CHO,…)’
Line 231: Move HESI settings into the Experiment’s section
Line 283: Replace ‘chemicals’ with ‘molecular formulae’
Line 287: Replace ‘new chemical formula’ with ‘additional chemical formulae observed in the current study (also referred as ‘new chemical formulae’ below)…
Line 325: Replace ‘a number of oxygen atoms increasing to 9’ with ‘up to 9 oxygen atoms’
Line 326: Replace ‘globally’ with ‘mainly’ (Please replace ‘globally’ across the text as this is not the correct choice of word in English).
Line 337: ‘global’ not sure if I understand this sentence… please rephrase
Line 465: Figure 9, capitalise ‘Representation’
Line 469: Remove this sentence as it does not provide any information or value to the results and discussion
Line 478: Replace ‘we noticed that’ with ‘our study suggest that’
Line 478: Complete the sentence as it is not clear similar to what?
Line 492: Remove ‘ former atmospheric chemistry’ from the sentence
Line 513: Replace ‘In any case, with’ with ‘Visualisation tools (e.g. VK diagrams, DBE plots) allowed to differentiate a number of the molecules that are likely related to the experimental conditions used in the current study (e.g. low temperature combustion)’
Line 514: Rephrase ‘Among the chemical formulas observed in this work, some had not been reported in the 9 atmosphere-oriented studies considered here for comparison’ with ‘Among the chemical formulae observed in this work, some have not been reported in the studies considered here for comparison. It should be noted that other factors including experimental conditions (e.g. the use of flow tube reactor vs smog chambers) and/or MS instrument acquisition parameters (e.g. as demonstrated in the SI Figure 9) can be responsible for the observed differences with the compared studies.

I have suggested to add a statement to the introduction and conclusion section to address the two reviewer’s comments on the relevance of the work to the atmospheric chemistry but for some reason it wasn’t taken on board. I strongly suggest, adding a statement (at least as suggested above for line 514) to address this concern.


Please make sure you either use US or British English across the whole text. Also, please be consistent with your choice, it is either ‘formulae’ or ‘formulas’ but not both.
Please harmonise the font size in the SI Figure 9 caption to the rest of the figure captions.

Thank you for resubmitting the manuscript.
Please complete this sentence: 'Our study suggest that in the absence of ozone, the oxidation by the OH˙ radical, common to ozonolysis, gives similar results'. Do you mean similar to previous studies considered in this work? If yes, then it needs to be stated here. I believe this was flagged and requested in the last editorial comments.

Kind regards