System for production of high yield of ions in RF only confinement field for use in mass spectrometry

A system for production of high yield of ions for use in a mass spectrometer (MS), comprising:

• a) an ion discharge tube comprising a cathode tube and an anode surface, wherein the cathode tube has a first inlet to provide analytes, a second inlet to provide a makeup gas and an outlet, and a high voltage source applied on the ion discharge tube to generate an ion flow;
• b) a first ion guide, being a multipole ion guide having a set of rods which are AC or DC voltage electrodes, configured with predefined radial diameters, an exit lens and a set of insulators, and having an entrance aperture and an exit aperture, wherein the entrance aperture is aligned with the outlet of the ion discharge tube, and wherein, an RF field of the first ion guide has a set of zero-field-lines along an x-axis and a y-axis that are central lines of a cross section of the first ion guide, and a z-axis that is along the length of the rods;
• c) a third inlet on the first ion guide to inject a reagent into the first ion guide, and whereby meta-stable neutrals are quenched by introducing the reagent through the third inlet;
• d) wherein the multipole ion guide is pressurized by the leakage from the outlet of the ion discharge tube to be sustained at a few mTorr by a vacuum pump,
• wherein analytes and a background gas are introduced at the first and the second inlets of the cathode tube, wherein the ion flow is injected into the set of zero-field-lines, and wherein the analyte is ionized through ion-molecular reaction before introduction into the MS, and since ions are injected in the set of zero-field-lines, the trajectories of ions are substantially parallel and collimated inside the MS.