In addition to the effect of the interface, the measured IEs of bulk water can also be affected by the presence of solutes. Both microjet and dip-and-pull experiments are carried out using electrolyte solutions (i.e., NaCl, KOH) to mitigate the effect of creating charges in the jet (due to ionization) that can affect the subsequent ionization. The possible effect of ions present in these solutions on the IE of the bulk solvent is usually ignored, although it might be non-negligible. Finally, the measured IEs always contain contributions from both the surface and the bulk species because the photoelectrons have finite escape depth (determined by the inelastic mean free path). The contribution of the bulk increases at higher photon energies. The simulations 22 suggest that the apparent peak position of liquid water can vary by as much as 0.3 eV as the inelastic mean-free path changes from 3 to 50 Å.