The working principle of an ion source involves the ionization of the sample molecules. For instance, in Electron Ionization, electrons are emitted from a heated filament and collide with the sample molecules, causing them to lose an electron and become positively charged. In Electrospray Ionization, the sample is passed through a high-voltage needle, creating a fine spray of charged droplets. As the solvent evaporates, the sample molecules become ionized.
