Patent ID: 6586731
Filing Date: 2003-07-01
Classification: H01J

Abstract:
An apparatus for providing gas phase ions in a relatively low pressure region from a liquid, the apparatus comprising:(a) a capillary tube, said capillary tube having an input for receiving the liquid, a longitudinal bore, and an outlet for discharging said liquid at a preset flow rate into a first region at a relatively high pressure; (b) a first interface element with an aperture therein and separating said first region from a second region at a relatively low pressure; (c) an electrode located downstream from the outlet of the capillary tube; and (d) a voltage source for generating a voltage potential between said liquid in the capillary tube and said electrode; wherein the outlet of the capillary tube is aligned with the aperture of the first interface element and is positioned directly in front of, and in close proximity to the aperture of the first interface element, whereby, in use, with a sufficient voltage potential applied between the liquid and the electrode to form an electric field sufficient to cause the liquid stream flowing through the outlet of the capillary tube at the preset flow rate to become a liquid stream in the form of a Taylor cone having a jet region that originates at the outlet of the capillary tube and flows through the aperture of the first interface element into the second region and substantially desolvates into gas phase ions in the second region, and wherein the spacing between the outlet of the capillary tube and the aperture of the first interface element is such that the jet region of the Taylor cone is positioned within the aperture of the first interface element so that the liquid stream disperses into charged droplets substantially in the second region.