is larger than about 4 M, as shown in Figure . Such kind of dependence has also been found in the cases of nitrites and nitrates, and it was rationalized in terms of Langmuir adsorption model, where the surface sites for these ions are limited, leading to a constant plateau of surface concentrations at higher bulk concentrations. For nitrites and nitrates, their maximum interfacial concentrations are 2.25 M and 5.3 M, respectively. Finally, Figure plots the values of k SLR retrieved from Scenario 3 as a function of droplet ionic strength, and the corresponding value of b SLR in eq 2 is equal to (4.8 ± 1.1) × 10 -2 M -1 , again confirming the positive ionic-strength dependence of k SLR .