The manuscript by Li et al. summarized batch leaching protocols affecting aerosol trace element solubility. They compared three items, namely, agitation methods, contact time, and filter pore size to identify the difference in these experimental parameters would affect the aerosol trace element solubility. Moreover, they also compared solubility determined using protocols commonly adopted by four labs (GIG, ZJU, OUC and NIO). Their laboratory research helps to understand the impact of different processing methods on the solubility of metal elements. After addressing the following minor issues, I recommend their research to be published.

1. Number of samples should be added in each subgroup in Table 1.
2. There are two points in Figure 2e that show a clear large difference in the solubility of Cu obtained using the two methods, why?
3. As can be seen from the Figure 3, why element solubility conducted by the contact time from 1 to 2 h higher than that from 2 to 4 h?
4. What do the blue lines and texts in Figure 4 represent? What does the red cross represent?
5. In this study, the authors only compared the differences between the different pre-treatments, not the differences measured by the different instruments, so there were no significant differences between methods (mainly pre-treatments), which might not be the case if they use different instruments (ICP-MS VS. ferrozine technique methods). Please add a short discussion to discuss this issue and refer to some of the literature, e.g. Zhu et al. 2022, 22 2191–2202.

In this manuscript, Li et al. conduct a comprehensive examination of how agitation methods, filter pore size, and contact time influence the solubility of nine aerosol trace elements through ultrapure water batch leaching techniques utilized across various labs. The findings indicate that the impact of these variations on solubility measurements is minimal, underscoring the necessity for standardized leaching procedures and the endorsement of ultrapure water batch leaching as a baseline protocol. Given the array of leaching protocols previously employed to extract dissolved aerosol trace elements, discerning the disparities among them is crucial. Overall, the article presents its results clearly, boasts a logical structure, and is well-written. Therefore, I recommend its publication once the minor issues listed below are addressed.

1. The authors should briefly elucidate the rationale behind the selection of the nine elements for study in the introduction or methodology section. It is important to convey to the readers the representational significance of each element, ensuring that the selection appears deliberate rather than arbitrary.
2. As the core of the article revolves around the comparison of analytical methods, the details of the methods should be more thoroughly delineated. (a) The authors mention collecting four sampling blanks and three laboratory blanks. They should elaborate on how these were utilized to correct the results and to what extent they affected the outcomes. Also, whether the analysis of blanks differs with the method should be detailed. (b) The use of ICP-MS for analysis is noted. It would be beneficial for the authors to introduce the QA/QC of ICP-MS analysis, particularly by providing information on the Method Detection Limits (MDL). Details on the ICP-MS used at NIO, if available, should be also included.
3. In Table 1, some cells are empty, which looks unprofessional. It is recommended to write 'NA' or use a dash line with a footnote for clarification. Additionally, what does 'lab' in the header signify? Is it a lab code or the location where the experiment was conducted?
4. Lines 184-185: A single sentence as a paragraph is inappropriate; it should be combined with the preceding section.
5. Table 2 displays t-test results, yet the discussion suggests that even with significant differences for certain elements, the discrepancy is minor. Thus, the importance of t-test outcomes seems diminished, and it is suggested to place them in supplementary materials.
6. The dashes in Table 3 should be explained in a footnote.
7. In Figure 4, panels b and c, the authors should clarify the presence of two sets of equations (one black, one blue). Is it because one set excludes outliers? If so, how were these outliers determined? This should be clearly explained. Based on Figure 4(b), the presence of outliers appears to have a minimal impact on the linearity of the data.
8. Minor Issues: (a) When describing the correlation coefficient, should it be capitalized as 'R' or 'r'? The manuscript uses both; please check and standardize throughout the text. (b). In Tables 1 and 2, some content is bold and underlined. While the intent to emphasize is clear, uniform formatting or an explanation in the footnote would be advisable. (c). The use of red to highlight information in the figure axis titles is unnecessary, as clarity is already achieved without it.

Please see the detail comments in the attached file.