Outline
Mass spectrometric ionization methods have traditionally been developed to study molecules present in the gas phase. A major disadvantage of gas phase ionization methods is that they do not allow the study of non-evaporable materials. Examples of such compounds are proteins, peptides, carbohydrates, nucleic acids. The invention is based on the recognition that a sufficiently high velocity jet of liquid carries sufficient energy to tear particles out of the test surface, thus also providing the possibility of depth analysis, which is also suitable for in vivo experiments. The present invention relates to a process for the conversion and analysis of certain components of condensed phase materials into gaseous ions, in which ions or ionizable particles are extracted from the material to be analyzed with an analytical beam from at least one sampling unit and analyzed in an analyzer. A liquid jet as being the analytical beam is used for this process, so that the liquid is evaporated from the droplets formed at the junction of the liquid jet and the substance to be analyzed. For analytical purposes, either the liquid droplets themselves, or the particles obtained by evaporating the liquid are ionized before analysis. The invention further relates to the means for converting certain components of condensed phase samples to gaseous ions and to the means for converting certain components of condensed phase samples to gaseous ions suitable for forming a cavity in the sample or cutting the sample.