FIELD-EFFECT ION SOURCE Russian patent published in 1995 - IPC

FIELD: analytic instrumentation for high- sensitivity mass spectrometric analysis. SUBSTANCE: analyzed liquid 5 from vessel 6 is applied in the form of drop on to membrane 1 which outer surface is under atmospheric pressure. Membrane 1 presents nuclear filter covered with thin layer of protective fluid 2 which separates atmosphere from vacuum volume of chamber 4 of mass spectrometer. Thanks to small diameter of pores of nuclear filter and selection of fluid with special properties this fluid does not leaks through pores of nuclear filter under action of atmospheric pressure and provides for transport of ions and for their evaporation in vacuum. Under action of electric field created with electrodes 7 and 8, one of them being in analyzed liquid 5 and the other one - in vacuum, ions pass from analyzed liquid 5 through layer of protective fluid 2, are emitted into vacuum and accelerated towards mass analyzer. Special technological and design features of technical approach provide for performance of analysis of liquids under flux of neutral molecules 10¹⁵ mol/s hitting chamber of mass spectrometer. EFFECT: reduced mass and dimensions of ion source. 2 dwg