Patent ID: 6297499
Filing Date: 2001-10-02
Classification: H01J

Abstract:
A method for characterizing solute species in a liquid solution which comprises the following essential steps:(a) immersing the entrance end of a wick element in said liquid solution, said liquid solution comprising at least one solute species in a vaporizable solvent, said wick element comprising a porous permeable aggregate of material that is wettable by said liquid solution so that capillarity causes said solution to migrate through said wick to the exit end opposite from the entrance end immersed in said liquid solution,(b) maintaining, as in conventional electrospray ionization, a potential difference between said wick and its surroundings that is large enough to produce at the exit end of said wick element an electric field sufficiently intense to disperse the arriving liquid into ambient bath gas as a fine spray of charged droplets, said ambient gas being maintained at a pressure sufficiently high to prevent formation of an electrical discharge in said gas by said electric field,(c) allowing solvent to evaporate from such charged droplets, thereby producing gaseous ions from at least some of said solute species,(d) characterizing said gaseous solute ions by measurement of at least one of their properties.