Ion formation by [Li]+ ion attachment in high electric fields

An improved method for ionization by [Li]+ ion attachment in high electric fields is described in which gaseous molecules collide with a tungsten wire covered with a lithium salt. The simple mass spectra of a number of compounds which exhibit only [nM + Li]+ ions demonstrate the particular advantage of this ionization method. So far, additional peaks resulting from reactions of the molecules with the salt on the emitter surface have been found only in the mass spectra of acids.