The Effects of Solvent Extraction on the Functional Group Structure of Long-Flame Coal
Round 1
Reviewer 1 Report
In the manuscript, various solvents were used to extract long flame coal. Through Fourier transform infrared spectroscopy data analysis, it was found that except for AOT, the concentration of functional groups in the extracted coal was decreased compared with that in a control specimen extracted using only water. Ethanol, n-hexane and methanol provided the optimal extraction efficiencies in terms of capturing coal molecules having aromatic structures, aliphatic structures and oxygen-containing groups, respectively. The results of this work are expected to assist in future research concerning the extraction of coal molecules having specific functional groups. So, the manuscript is recommended to be accepted for publication. However, there are still few problems need to be modified as follow:
1. Page 2, line 13, Please further confirm whether the compound names "DL-epiloliolide, N-p-hydroxy-cis-coumaroyltyramine, β-Sitosterul" are correct. In addition, there are many professional terms involved in the article, please confirm the correctness of these words.
2. Page 6, line 8, "solubilization effect" please explain, the meaning here is unclear;
3. Page 8, line 15, please explain "extractions with synergistic mixtures", which method is not mentioned in the previous article;
4. Page 9, line 1, "with a water extraction as a control" Please specify why the water extraction control group is set up;
5. Page 16, line 8, "The best-performing solvents for aromatic groups were therefore n-hexane, CYH+AOT+AE and AE." The text above seems to show an order based on the > symbols that shows these solvents gave the lowest performance but here you say that they were the best solvents. Please explain;
6. Page 17, line 21, The data in this conclusion should correspond to that in Table 3, but "Extraction rate" is used in Table 3 and "extraction efficiency" is used here. Please confirm which one is correct and modify it;
7. Some of the figures in the paper have a right scale line, some do not have a right scale line, please modify the format to make them as uniform as possible;
8. In Table 2, the first letter of the title bar is not uniform, please modify the format to make them as uniform as possible;
9. Table 1 ang Table 5, the current table content is not clearly divided, please consider adding more lines to make the table content more understanding;
10. Please modify the reference format again to make it as uniform as possible.
The quality of English language fit for the publication.
Author Response
请参阅附件。
Author Response File: 
Author Response.docx
Reviewer 2 Report
Dear authors, the submitted article is interesting but requires editorial correction in terms of indicating literature items in the text. Please indicate the source for the figures or indicate that it is your own work. Please consider separating the 'Discussion' section from the overall content of the article.
Author Response
Please see the attachment.
Author Response File: Author Response.docx
