The work by Honga et al. investigated distribution of several organic tracer compounds, water-soluble inorganic ions in PM2.5 and gas phase HCl, HONO, HNO3, NH3 species in coastal areas of South-eastern China. The authors employed well established analytical techniques for identification and quantification of tracer compounds (e.g. TMS derivatisation). The obtained results are interesting and can be useful for researchers dealing with tracer compounds. I recommend this work for publication under Measurments Reports after considering my comments below:

Materials and methods:

The authors use a single internal standard (IS) to cover fifteen organic tracer compounds: Lines 152-153 state "At last, 140 μL of internal standard solution (13 C n-alkane solution, 1.507 ng μ L -1 ) was added into the samples”. The majority of considered tracer compounds are of highly polar nature (containing hydroxylic groups). What was the rationale for selecting a non-polar ¹³C n-alkane as an IS for polar compounds? One of the requirements for IS that it should structurally resemble the analyte of interest (structural analogue or stable label) such that it behaves similarly during sample preparation and analysis (Lowes et al., 2011). The IS that is added to each sample compensates for unavoidable assay variance due to, for example, extraction efficiency, ionisation effects and transfer losses, and thus I am concerned about the discussion of correlation of various tracers in this work if the observed variability or absence of correlation could be due to other than environmental variability factors.

Results and discussion:

The authors give a fair description of isoprene oxidation products; however, I can’t say the same about the other discussed tracers. For example, I realise that levoglucosan is commonly used as a marker compound for biomass burning; however, nothing is stated about stability of this compound. It has been shown that the oxidation of levoglucosan in atmospheric deliquescent particles is at least as fast as that of the other atmospherically relevant organic compounds and levoglucosan may not be as stable in the atmosphere, especially under high relative humidity conditions (Hoffmann et al., 2010). Can this be one of the reasons for absence of correlation with other tracers? Could you elaborate why are you expecting a correlation of CPA with levoglucoasan (lines 357-358)? This is not clear to me. As I understand, the applied derivatisation technique allows separation of other biomass burning markers e.g. mannosan and galactosan, which often accompany levoglucosan. Have the authors observed these isomers along with levoglucosan? The relative ratios of levoglucosan to mannosan have been used for source reconstruction of combustion derived byproducts in atmospheric aerosols (e.g. Iinuma et al., 2007, 2009, Engling et al., 2009) and can be useful to support some of the conclusions made in this work.

Conclusion section:

At least the way how it is formulated in the text I find it rather difficult to see how the presented work led to the conclusion that there is an impact from anthropogenic–biogenic interaction.

Minor comment:

Line 27 (page 23) The authors state "These results also proved the obvious effects of anthropogenic emissions on secondary formation of aerosol particles under atmospheric relatively stability conditions during the winter.”  I think the use of correlations is indeed helpful to support some specific trends; however, I believe such data processing techniques are not sufficient to provide a definite answer on the specific emission source and therefore the words such as “obvious” should be avoided  (at least in this context), or supported by other than correlation data.

References:

Engling, G., Lee, J., Tsai, Y.-W., Lung, S.-C.C., Chou, C.C.-K., Chan, C.-Y., 2009: Size resolved anhydrosugar composition in smoke aerosol from controlled field burning of rice straw. Aerosol Science and Technology 43, 662–672.

Hoffmann, D.; Tilgner, A.; Iinuma, Y.; Herrmann, H. ,2010: Atmospheric Stability of Levoglucosan: A  Detailed Laboratory and Modeling Study. Environmental Science & Technology. 44:694- 610 699; DOI: 10.1021/es902476f

Iinuma, Y., Bruggemann, E., Gnauk, T., Muller, K., Andreae, M. O., Helas, G., Parmar, R., and Herrmann, H. 2007: Source characterization of biomass burning particles: The combustion of selected European conifers, African hardwood, savanna grass, and German and Indonesian peat, J. Geophys. Res.-Atmos., 112, D08209, doi:10.1029/2006JD007120.

Iinuma, Y., Engling, G., Puxbaum, H., and Herrmann, H.: A highly resolved anion-exchange chromatographic method for determination of saccharidic tracers for biomass combustion and primary bio-particles in atmospheric aerosol, Atmos. Environ., 43, 1367– 1371, 2009

Lowes S, Jersey J, Shoup R, Garofolo F, Savoie N, Mortz E, Needham S, Caturla MC, Steffen R, Sheldon C, Hayes R, Samuels T, Di Donato L, Kamerud J, Michael S, Lin ZJ, Hillier J, Moussallie M, de Souza Teixeira L, Rocci M, Buonarati M, Truog J, Hussain S, Lundberg R, Breau A, Zhang T, Jonker J, Berger N, Gagnon-Carignan S, Nehls C, Nicholson R, Hilhorst M, Karnik S, de Boer T, Houghton R, Smith K, Cojocaru L, Allen M, Harter T, Fatmi S, Sayyarpour F, Vija J, Malone M, Heller D. 2011: Recommendations on: internal standard criteria, stability, incurred sample reanalysis and recent 483s by the Global CRO Council for Bioanalysis. Bioanalysis. 3(12):1323-32. doi: 10.4155/bio.11.135. PMID: 21679026.

Review on “Measurement Report: Effects of anthropogenic emissions and environmental factors on biogenic secondary organic aerosol (BSOA) formation in a coastal city of Southeastern China” for Hong et al.

The author conducted the field observation during summer and winter in the southeast of China, and discussed the formation of SOA tracers, especially BSOA tracers. The author found that the concentrations of SOA tracers were affected by photochemical oxidation in summer, and were affected by anthropogenic emissions in winter. They highlighted that anthropogenic emissions, atmospheric oxidation capacity and halogen chemistry have significant effects on the formation of BSOA in the southeast coastal area. The manuscript can provide unique data for SOA tracers in the coastal area, and clarified the influencing factors on SOA formation. However, there are still some content deficiencies and logical omissions in this manuscript, which need to be carefully revised. Overall, the manuscript could be accepted after addressing the following issues.

1. Line 147-149. How many times the samples were ultrasonically extracted during the pre-treatment, it should be shown in the manuscript.
2. Line 189-190. f_SOC of isoprene was 0.155 ± 0.039 in study of Kleindienst et al., 2007, the author should recheck your content.
3. Section 2.5. The authors use both E-AIM IV model and ISORROPIA II model to calculate the aerosol pH. They need to discuss the correlation and difference between the results of two models, and explain which result is more reasonable for this manuscript. The authors should also explain which model they chose for the following discussions.
4. Section 3.1. In my opinion, it is clearer to list the average concentrations of these air pollutants during summer and winter, daytime and nighttime in Supporting Information as a Table.
5. Line 250. The average concentrations of SOA_M, SOA_I and SOA_C in winter and summer should be given. As the author determined to discuss “total SOA tracers” (Line 249), the concentration of ASOA should also be shown here.
6. Line 250-252. The author showed that “In summer, BSOA tracers showed much higher concentrations in the daytime than in the nighttime, while inverse results were observed in winter”, the specific concentrations of BSOA tracers in daytime and nighttime of summer and winter should be displayed here.
7. Line 252-258. Instead of using “for example” here, the author could display the average concentrations of SOA tracers (including SOA_I, SOA_M, SOA_C and ASOA tracers) during day, night, summer and winter in the Supporting Information as a Table directly.
8. Line 275-279. As the concentrations of SOA tracers were higher in summer than winter, and the f_SOC values were constant in this manuscript, it was not surprisingly that the concentrations of SOC in summer was higher than that in winter. And this result could not demonstrate that the contributions of SOA tracers to SOC in summer was higher than those in winter.
9. Line 283-286. This sentence is confusing, why does the “obvious trend of diurnal variations of SOC_I” was “consistent with the isoprene emission”, and why this result was compared with the trend in winter? Considering the coherence of context, maybe the author intended to explain the diurnal variation of SOC_I was obvious in summer and the variation was consistent with isoprene emission in summer? The authors should give more explanation about it.
10. Figure 3. The legend of Figure 3 might be SOC_I, SOC_M, SOC_C and ASOC.
11. Line 306, it should be “SOA_I tracers”, and Line 308, it should be “SOA_M tracers”.
12. Line 319. I think the first (PA and PNA) and later generation (HGA, AGA, HDMGA and MBTCA) products could only evaluate the aging degree of SOA_M, not all BSOA.
13. Line 333-335. According to the logic of this section, it might be “Low ratio of HGA/MBTCA (~1.0) showed that α‑pinene was the major precursor for SOA_M. The ratio of HGA/MBTCA with an average of 5.78 in Xiamen was high, suggesting the contribution of β‑pinene to SOA_M”.
14. Line 362. The author used the pH values calculated by ISORROPIA II here. Same as the Q3, the author should explain why they chose the pH calculated by ISORROPIA II, but not that calculated by E-AIM IV.
15. Line 380. Table 1 should be listed after this paragraph, which refers to table 1 for the first time.
16. As the contents of Figure 6 and Table 1 are similar, and the author has not discussed Figure 6 in detail, this figure should be moved to the supporting information section.
17. Line 425-427. The author showed that “the correlations of SOA tracers in winter were found to increase with increasing NH₃ and chlorine ions in PM_2.5, while inverse results were observed in summer”. The sentence is not rigorous, because NH₃ was not negative correlated with SOA tracers in summer as shown in Table 1.

I think this is a good submission to ACPD along the current line of thinking in atmospheric chemistry. The authors investigated ambient PM2.5 in coastal areas of South-eastern China and reported experimental distribution of the main organic tracers (mainly BSOA), water-soluble inorganic ions and gas phase species including HCl, HONO, HNO3, NH3. The analytical method (qualitative and quantitative) used by Honga et al. is well established for these oxygenated compounds. The results of this study show that the concentrations associated with SOA organic tracers depends on the photochemistry in summer, and on the emission of anthropogenic compounds in winter. The results of this study are interesting to the scientific community including modeling as it provides experimental link between photochemistry, anthropogenic emission and BSOA tracers in a coastal area of southeastern China. This work would be beneficial for publication under Measurments Reports after considering my comments below:

The analytical technique used IS and the authors should comment on the use of only one non-polar IS. I do recognize the difficulties of finding the correct IS due to co-elution issue with the number of oxygenated species that are detected in ambient PM2.5. Ketopinic acid is used by several groups as IS as it could not be detected in ambient PM and is a polar oxygenated specie!!

Are additional compounds associated with isoprene detected (hydro-carboxylic acids)?

The authors should provide additional evidence from the present work on the interaction biogenic-anthropogenic and its effect on PM formation.