In solvent assisted ionization inlet (SAII), the liquid sample is introduced directly in a heated inlet tube, with no applied voltage. The ionization mechanism is based on a heat-induced (statistical) charge separation at sub-atmospheric pressure. The resulting desolvation process is then similar to the desolvation process in ESI. It was thus postulated that the internal energies of ions generated from these two ionization modes should be close . A survival yield comparison between SAII and ESI was performed using substituted benzylpyridinium ions and an Orbitrap Exactive mass spectrometer .