Abstract: The invention relates to the ionization of analyte molecules on a solid surface close to atmospheric pressure as an ion source for mass spectrometers. The invention uses a spray mist from an electrospray apparatus to ionize the analyte molecules, for example a spray mist created by spraying pure water, which generates predominantly multiply charged ions of the analyte molecules which are particularly suitable for fragmentation.

Abstract: The invention relates to the identification of substance ions, which are usually generated by electro spray ionization after separation by liquid chromatography or capillary electrophoresis, with the help of libraries with mass spectra. The substance ions are frequently formed not only in a protonated (or deprotonated) form but also as adducts with cations or anions, a fact which complicates identification. The invention involves making identification more accurate by additionally carrying out a determination of the most probable molar mass with the help of adduct patterns.