Overall this paper is very well written and gives a good description of the application of a new technique to gain knowledge with respect to the speciation of black carbon containing aerosols. I would recommend this paper for inclusion to this journal after some minor revisions and other points are considered. Points are listed below.

1. Line 103: Vmode is the standard default mode of operation for any field measurements with AMS. This is just a wording thing but when you state cost of lower resolution it makes it sound as if you are running the instrument in sub optimal which you really aren’t. I know W mode gives you 2*resolution in V mode but at about 1/10 the sensitivity so V mode is the typical default mode.
2. Line 319; the thickly coated particles could also be from a dirty combustion source like BB or cooking which is heavily coated on primary emission.
3. Line 234; can you get insight to the SO4 makeup by looking at the cconventional AMS data as well
4. Line 243; I understand the need for both of these assumptions. Internally mixed within BC wont vap with conventional hearter and the instruments had different size cut lenses Standard vs 2.5 Can you give any information like size profile with SMPS or just theory to back up these assumptions.
5. Line 273 good point mz 36 bias
6. Line 279 good point on larger particles more likely to trigger
7. Line 286 good point on some particles having poor overlap and therefore only partial vap.
8. Lines 340 – 360 Are any of these metals being seen without BC? I know the laser does vaporize many elemental metals. If so could help differentiate between BB and dust.
9. Lines 370 – 380 Could this also be due to not enough ions with smaller particles to trigger an event.
10. Line 390 Should be C5+
11. Line 435 – 439 Again is any of this metal without BC?
12. Lines 495 497 Good point on the isobaric issues.
13. Figure 1 a-d I assume the shading is error bars for the SP-AMS measurements but I don’t see this stated anywhere.
14. Figure 3 e-j This highlights the issue of smaller sizes not being detected as well with event trigger.

This paper investigates chemical properties and mixing state of BC-containing particles by

using both Aerodyne laser-only SP-AMS and single particle AMS during a field campaign, It

provides a very valuable dataset that allows comprehensive analysis on the BC aerosol

properties, the paper is very well written and the interpretation of the observed results is robust and trustworthy, the paper can be accepted after a minor revision, the questions are listed below:

1. line285: Did you remove the tungsten in the ETSP mode?
2. line310: The figure of back trajectories should point to Fig. S8b.
3. line95: I think it would be more interesting to present a comparison of the composition between rBC-PM₁ and NR-PM_1~2.5, as well as between rBC-PM₁ and NR-PM₁ separately in Fig.1.
4. Have you assessed the impact of BC-free particles in ensemble measurements? It is noteworthy that they exhibit a higher presence in organic components at m/z 29, yet a lower presence at 60 and 73 in the ensemble compared to those in ETSP (Figures 3c and 3e).