(1) CIUsuite2 could only distinguish two populations each time, and (2) each CIU curve is treated independently, while in our dataset we postulate that the data for the same sequence in two pH conditions should be processed together, as we suspect that the same gas-phase ensembles should be involved, just in different proportions. As there was more to do with the data, we turned to the MCR-ALS deconvolution procedure.