PROCEDE D'OBTENTION D'IONS POUR L'INVESTIGATION, PAR SPECTOMETRIE DE MASSE, DE LA STRUCTURE MOLECULAIRE D'UN COMPOSE NORMALEMENT SOLIDE ET NON VOLATIL

摘要

In mass spectrometry, the conventional methods of ionisation are unsuitable or of low efficiency for substances which are normally solid and which cannot be evaporated in a stable form. Such substances, which include many compounds of biomedical importance, are amenable to a method of ionisation in which the compound is subjected to bombardment by a beam of neutral atomic particles. A target coating is produced in which a sample of the compound is present in a mobile state at the surface of the coating and the atomic beam is supplied at a low angle which is within a typical range of 10 DEG to 30 DEG , relative to the surface. The kinetic energy of the beam concerned is such that, during the mass analysis, a range of ion species which comprise both pseudo-molecular ions and structurally significant fragment ions is observed or detected. The mobile state may be the molten state or a solution in a carrier of low volatility, such as glycerol. <IMAGE>