|The revised version addresses the concerns of the reviewers, with two notable exceptions. First, the authors still do not correct for wall losses, but now clearly state this and mention that this will affect the reported yields. I’m willing to accept that, as long as they state the direction of this effect (see comment regarding line 272 below). Second, the authors make an argument that particle phase may influence the results, but cannot be predicted. This is generally true, but in my opinion some of the information provided in their responses to reviewers’ comments would be very helpful to readers if included in the manuscript. Specifically, the differences between the inorganic components ammonium sulfate (solid at all RH used in the study) and ammonium bisulfate (liquid at all RH used in the study except <2% RH) are significant and should be mentioned. The authors could also mention the caveats (also given in their response to reviewers’ comments) that the organic phase could lower the DRH of ammonium sulfate and cause it to deliquesce at 75% RH (but not likely at 0 or 50% RH), and that the formation of significant quantities of methylglyoxal oligomers could cause liquid aerosol particles (or liquid organic particle phases) to become semi-solid. Based on the work of Bertram et al.,(1) I think the authors can confidently state that at 0 and 50% RH, ammonium sulfate will be present in crystalline form along with an organic phase (of unknown viscosity), while at 50 and 75% RH crystalline ammonium bisulfite will not be present. If the authors included seed particle loadings, readers could interpret the ammonium sulfate data according to the organic / sulfate ratio framework of Bertram et al.(1)|
Line 75: The statement “The method is applicable for all oligomeric compounds, which can be decomposed into methylglyoxal monomers” is misleading as currently stated. It would be clearer to state “The method is applicable for any oligomeric compound which can be decomposed into methylglyoxal monomers.”
Line 133: Technically, the filter extract that was not heated is not measuring only methylglyoxal monomers, but also any compound that can be hydrolyzed at room temperature into methylglyoxal monomers. This likely includes some acetal oligomers. Also, the authors should make clear at some point in the manuscript that “methylglyoxal monomers” includes singly and doubly hydrated methylglyoxal.
Line 394: There also might be oligomers originating from methylglyoxal monomers that are not heat-decomposible back to methylglyoxal monomers, which would also not be determined in the present study.
Line 20: The phrase “emitted hydrocarbons contributing with up to …“ would be clearer if written as “emitted hydrocarbons, contributing up to …”
Line 24: “low-volatile” should be “low-volatility”
Line 111: “m” should be “m3” (cubic meters)
Line 127 and 271: I think that “Noticeably” should be “Notably”
Line 148: it would be helpful to give essential parameters of this method here.
Line 272: The phrase “ …might have an influence on the reported SOA yields.” would be more informative as “…might exert a downward influence on the reported SOA yields.”
Line 299: The phrase “… controversially discussed in the literature” could be changed to a single word “… controversial”
Table 4: It would be good to include the results of the present study in Table 4.
1. Bertram, A. K.; Martin, S. T.; Hanna, S. J.; Smith, M. L.; Bodsworth, A.; Chen, Q.; Kuwata, M.; Liu, A.; You, Y.; Zorn, S. R., Predicting the relative humidities of liquid-liquid phase separation, efflorescence, and deliquescence of mixed particles of ammonium sulfate, organic material, and water using the organic-to-sulfate mass ratio of the particle and the oxygen-to-carbon elemental ratio of the organic component. Atmos. Chem. Phys. 2011, 11, 10995-11006.