Public University Corporation Yokohama City University

Shimadzu Corporation

Amr Corporation

Mitsuo Takayama

Kanako Sekimoto

Daisuke Okumura

Motoshi Sakakura

Hiroshi Hike

An atmospheric pressure ionization method uses: a gas flow passage control unit () and a gas outlet nozzle () configured to jet argon gas to an atmospheric atmosphere; a needle electrode () arranged between an outlet port of the gas outlet nozzle () and an introduction port of an ion introduction pipe () that includes a tip end portion formed into a two-sheeted hyperboloid of revolution having a radius of curvature of 1 &#x3bc;m or more and less than 30 &#x3bc;m; a needle electrode support mechanism (); and an electric power generation unit () configured to apply a voltage to the needle electrode (). The atmospheric pressure ionization method includes: applying a voltage of 1.8 kV or more to the needle electrode () from the voltage generation unit () to generate a dark discharge; exciting the argon gas with the dark current; and causing the excited argon gas and the sample to react with each other, to thereby ionize the sample.

Atmospheric pressure ionization method

In the ionizer of the present invention, a stream of gas spouted from a nozzle () of a DART ionization unit () vaporizes and ionizes the components in a sample (). Gaseous sample-component molecules which have not been ionized by that process are subsequently ionized by a reaction with a reactant ion produced by a corona discharge generated from a needle electrode (). Such a two-stage ionization of the sample-component molecules improves the ionization efficiency. A needle-electrode support mechanism () adjusts the position and/or angle of the needle electrode () and thereby controls a potential gradient. Therefore, a specific sample-derived ion species can be efficiently introduced into an ion introduction tube () and be detected with a high level of sensitivity.

Ionizer and mass spectrometer including first section for ionizing sample under atmospheric pressure while vaporizing or desorbing the sample component and second section for generating corona discharge

Growing community of inventors

Kanagawa, Japan

Mitsuo Takayama