Mass spectrometer of Thermo Finnigan LCQ type represents an instrumentation technique enabling separation of ions based on their m/z ratio. It is possible to perform repeating collision experiments (MSn) which play an important role in identification of wide spectrum of compounds, it is possible to connect it with capillary chromatography and/or capillary electrophoresis. The device is equipped with a series of ion sources (APCI, ESI, nano-ESI, DESI, nano-DESI)