INTERFACE FOR AN ATMOSPHERIC PRESSURE ION SOURCE IN A MASS SPECTROMETER

摘要

The invention relates to a mass spectrometer having an ion source region at substantially atmospheric pressure in which ions are formed from a liquid sample. The mass spectrometer further has an interface for transmitting the formed ions from the ion source region into a vacuum region which is held at a pressure level substantially below the atmospheric pressure and where the formed ions are further processed. The interface comprises a wall dividing the ion source region and the vacuum region and has a central orifice formed therein for letting pass gaseous and particulate matter from the ion source region into the vacuum region following the pressure gradient, wherein the central orifice is surrounded at least section-wise by a plurality of lateral orifices.