Liu et al. reported the cross-comparison between the measurement of a flight-aerosol chemical speciation monitor with the capture vaporizer and a PM2.5 aerodynamic lens (TOF-ACSM-CV-PM2.5) and other offline chemical analyses. Their results show great agreement between online and offline measurements, suggesting TOF-ACSM-CV-PM2.5 has good collection efficiency. The experiments were well designed, the manuscript overall is well written, and the conclusions are well supported. I just have a few minor comments for the authors. Thus, I suggest a minor revision of this manuscript.

Comments:

1. L115-117, “The mass … (6.6 m²/g).” I think 6.6 m²/g is a mass absorption cross section (MAC), not mass scattering cross section (MSC). Please confirm that and make changes accordingly.
2. Section 2.32 has some issues:
   1. Did you pre-bake the quartz filter? Moreover, quartz filters can adsorb gas species. Could you discuss how that could affect your results? I assume that will introduce more OC due to adsorbed VOCs and SVOCs.
   2. Did you weight filters before analysis to see if there was any change in weight during storage?
   3. I would never store filter samples under room conditions since samples might evaporate and/or react during storage. A recently published paper shows that storing filters under room temperature can significantly change the OC due to evaporation and oxidation (Resch et al., 2023). Please add a discussion regarding to potential change of sample due to storage. This is related to your discussion of NO3 loss from the filter in section 3.1.1 since your storage temperature is 20 C. It can also explain why you see more OM from ACSM than filters.
   4. It is not clear which filter you used for which offline analysis.
   5. For the thermal-optical method, it distinguishes OC and EC based on the different temperature steps. All CO2 that comes from He/O2 steps are considered to have originated from EC. Moreover, OE-EC has few artifacts due to VOC and SVOCs in the sample (Y. Cheng et al., 2010; Z. Cheng et al., 2019; Turpin et al., 1994, 2000). Also, EC is typically overestimated due to the pyrolysis of OC and strongly absorbing BrC (Z. Cheng et al., 2019). Please add relevant discussion about these artifacts.
3. Figure 1: The caption is not very clear. It should be stated that these dots are daily averages in the caption. What is the variance of online measurements?
4. L198-201, “A well-known … Pakkanen and Hillamo, 2002).” If this is true, you should always see filter has lower NO3 than ACSM. It actually suggests the difference between filter and ACSM should even be larger.
5. L257-263, “The eBC was … a reasonable result.” It is also due to MAAP measures eBC, which includes BC and any other species that absorb light at 637 nm (e.g., BrC). The MAAP also overestimates eBC due to multi-scattering effects and loading effects.

Liu et al. compared the performance of online TOF-ACSM-CV measurements against offline filter sample analysis. The results show that ACSM has a difference less than 10% from filter analysis for all the inorganic species, which indicates the good collection efficiency of the capture vaporizer. Additionally, TOF-ACSM-CV measurements overall agrees with MARGA in terms of inorganic species and with MPSS in terms of particle volume. The reasons for the differences are analyzed and discussed. I find this manuscript easy to read and overall well written. The manuscript can be published after the following minor comments are addressed.

Comments:

1. Line 112: Do you mean electrostatic losses? Why would stainless steel tubing reduce diffusional losses compared to other tubings?
2. Line 165: Why are the filters stored at 20C instead of at low temperatures? How long is it between filter collection and subsequent analysis? Any estimation about OC losses? A discussion on this should be added to section 3.1.1
3. Line 321: The newest WHO PM2.5 annual limit is 5ug/m3.
4. Line 338: Why does a low fraction of OC in PM 2.5 indicate organic compounds are more abundant in the PM1.0-2.5 range? There is also a typo: similar in PM1.0 and PM2.5
5. Figure S1: it should show chlorine and OA, not EC and OC.
6. Do the authors suggest an aerosol drying protocol to decrease the effect of humidity on the cut-off size?