Field desorption

Field desorption (FD) is a method of ion formation used in mass spectrometry in which a high-potential electric field is applied to an emitter with a sharp surface, such as a razor blade, or more commonly, a filament from which tiny "whiskers" have formed. This results in a high electric field which can result in ionization of gaseous molecules of the analyte. Mass spectra produced by FD have little or no fragmentation because FD is a soft ionization method. They are dominated by molecular radical cations M and less often, protonated molecules . The technique was first reported by Beckey in 1969.