Dear authors. Congratulations on a fine work further characterizing the use of EESI-MS approach for the analysis of particulate organics. Just minor issues remain:

Main text

P2,L17: citing the original AMS paper by Jayne (2000) and ToF-AMS paper by DeCarlo (2007) may be more appropriate here. A good summary of the most commonly cited AMS papers can be found here: http://cires1.colorado.edu/jimenez/ams-papers.html.

P2,L22: due to the very large number of ESI-MS-based atmospheric chemistry studies, citing a review could work better here (or emphasizing that these are just a few examples of applications of ESI-MS to atmospheric problems.

P2, L28: I have not checked other references listed here but (Bateman et al., 2010) does not apply here; it has no time resolved measurements. The authors may be referring to (Bateman et al., 2009), which reported time-resolved measurements (this paper is already in the reference list). (Bateman et al., 2010) should be removed from the reference list.

P3, L1: here and in a few other places, there is an unnecessary comma after et al. For example, “Doezema et al., (2012)” should be “Doezema et al. (2012)”. I would search and replace. Note that “(Gallimore et al., 2017b)” is correct, comma should be retained in in references in parenthesis.

P3,L9: missing space

P4,L13: Calculations of mole fractions normally include the number of moles of solvent in the denominator. The mole fractions cited here refer to the solutes only, without solvent. I presume the readers will figure it out but revising the text to remove this ambiguity would help.

P6,L3: not used -> was not used

P6, L15: is described -> was described

P11, Figure 2, also applies to other figures: I have been told by several mass spectrometrists that the use of term “intensity” is now discouraged in mass spectrometry literature. Terms like “ion abundance”, “relative ion abundance”, etc. appear to be preferred. If you adopt this convention, you will need to change labels in your figures and figure captions.

P14, L4: using “EESI-MS(–)” might be a little less awkward than “EESI(–)-MS”

P23, L11 and L25: unnecessary commas after the stated values

P24, Figure 9: I would edit the X-axis label to say “[OH-pinonic acid]” instead of “[OHPINONIC]”

Reference section:

Please fix subscripts/superscripts, for example in Edney et al. (2005)

Please fix title capitalization in Smith and Spanel (2005). It would also help to make the capitalization more uniform.



Supporting information section:

P1,L2: apparatus … are shown -> setups … are shown

P1, L13: instrumentation is -> instruments are

P4,L3: Saunders et al., -> Saunders et al.

P5,L4: represent represents -> represent

Figure S4, S5, S6, S7: “peak abundance” may be a more accurate in the Y-axis title (see above)