Ionization method and apparatus including applying converged shock waves to a spray

Patent metadata

Field	Value
Publication number	US-9103783-B2
Application number	US-93305808-A
Country	US
Kind code	B2
Filing date	Mar 17, 2008
Priority date	Mar 17, 2008
Publication date	Aug 11, 2015
Grant date	Aug 11, 2015

Abstract

A sample solution containing a sample component is sprayed onto an atmosphere at atmospheric approximately pressure while being applied with electric charge from the tip of a nozzle ( 1 ). A sample molecule is released as an ion in a process where charged minute liquid droplets collide with an atmospheric gas and are broken apart, and a solvent is vaporized from the respective liquid droplets. A reflectron ( 7 ) in the shape of a half-cut spheroid is arranged in such a manner that a second focal point (F 2 ) is positioned in front of an ion-introducing portion ( 4 ) in the spray flow. A discharge electrode ( 8 ) is disposed in a position at a first focal point (F 1 ) of the reflectron ( 7 ). When pulsed high voltage is applied to the discharge electrode ( 8 ), an electric discharge occurs, causing shock waves to be generated. The shock waves reflected on the reflectron ( 7 ) are converged on the second focal point (F 2 ). Due to the converged shock waves, the vicinity of the second focal point (F 2 ) rises to a high temperature, and a large pressure is also applied thereto. Therefore, vaporization of a solvent from the respective liquid droplets is further accelerated, allowing an ion to be easily generated. In addition, direct ionization can be expected. This makes it possible to improve ion generation efficiency.

First claim

The invention claimed is:

1. An ionization method for ionizing a sample component for mass spectrometry, comprising the steps of:
spraying with a spraying unit a sample solution containing a sample component to develop a spray flow including a minute droplet; and
applying converged shock waves with a shock wave generating member apart from the spraying unit for applying converged shock wave to the spray flow at a position immediately in front of an ion-introducing device in communication with a later stage, thereby accelerating vaporization of a solvent in the minute droplet so as to promote ion generation,
wherein the shock wave generating member comprises
a discharge source;
a discharge electrode connected to the discharge source, for generating electric discharge to produce shock waves; and
a reflector for reflecting and converging the shock waves produced by the discharge electrode, where the shock waves are converged at the position immediately in front of the ion-introducing device.

2. An ionization apparatus for ionizing a sample component for mass spectrometry, comprising:
a spraying unit for spraying a sample solution containing a sample component to develop a spray flow including a minute droplet;
an ion introducing device in communication with a later stage; and
a shock wave generating member for applying converged shock waves to the spray flow from the spraying unit at a position immediately in front of the ion-introducing device so as to accelerate vaporization of a solvent in the minute droplet,
wherein the shock wave generating member comprises
a discharge source;
a discharge electrode connected to the discharge source, for generating electric discharge to produce shock waves; and
a reflector for reflecting and converging the shock waves produced by the discharge electrode, where the shock waves are converged at the position immediately in front of the ion-introducing device.

3. The ionization apparatus according to claim 2 , wherein the spraying unit applies an electric charge to the sample solution and sprays the charged sample solution as charged droplets.

4. An ionization method for ionizing a sample component for mass spectrometry,
generating shock waves by a shock wave generating member, wherein the shock wave generating member comprises:
a laser beam source for emitting a laser beam;
a lens for converging the emitted laser beam to produce shock waves; and
a reflector for reflecting and converging the shock waves produced by the laser beam; and
wherein the converged shock waves are applied to a minute droplet of a sample solution to be analyzed at a position immediately in front of an ion-introducing device in communication with a later stage, thereby causing the minute droplet of the sample solution to be ionized.

5. An ionization apparatus for ionizing a sample component for mass spectrometry, comprising:
an ion-introducing device in communication with a later stage;
a shock wave generating means for applying converged shock waves to a minute droplet of a sample solution to be analyzed at a position immediately in front of the ion-introducing device,
wherein the shock wave generating member comprises:
a laser beam source for emitting a laser beam;
a lens for converging the emitted laser beam to produce shock waves; and
a reflector for reflecting and converging the shock waves produced by the laser beam, at a position immediately in front of the ion-introducing device; and
wherein the minute droplet of the sample solution is ionized by an effect of the shock waves.

6. The ionization method according to claim 1 , wherein the ionization method is an atmospheric pressure ionization method performing ionization in an atmosphere at approximately atmospheric pressure.

7. The ionization apparatus according to claim 2 , wherein the ionization apparatus is an atmospheric pressure ionization apparatus performing ionization in an atmosphere at approximately atmospheric pressure.

8. The ionization method according to claim 4 , wherein the ionization method is an atmospheric pressure ionization method performing ionization in an atmosphere at approximately atmospheric pressure.

9. The ionization apparatus according to claim 5 , wherein the ionization apparatus is an atmospheric pressure ionization apparatus performing ionization in an atmosphere at approximately atmospheric pressure.

10. The ionization apparatus according to claim 2 , wherein the reflector is a half-cut spheroid shaped shock wave mirror having a first focal point and a second focal point, the discharge electrode being placed at the first focal point and the shock waves being converged at the second focal point.

11. The ionization apparatus according to claim 3 , wherein the reflector is a half-cut spheroid shaped shock wave mirror having a first focal point and a second focal point, the discharge electrode being placed at the first focal point and the shock waves being converged at the second focal point.

12. The ionization apparatus according to claim 7 , wherein the reflector is a half-cut spheroid shaped shock wave mirror having a first focal point and a second focal point, the discharge electrode being placed at the first focal point and the shock waves being converged at the second focal point.

13. The ionization apparatus according to claim 5 , wherein the reflector is a half-cut spheroid shaped shock wave mirror having a first focal point and a second focal point, the laser beam being converged at the first focal point by the lens to produce the shock waves and the shock waves being converged at the second focal point by the reflector.

14. The ionization apparatus according to claim 9 , wherein the reflector is a half-cut spheroid shaped shock wave mirror having a first focal point and a second focal point, the laser beam being converged at the first focal point by the lens to produce the shock waves and the shock waves being converged at the second focal point by the reflector.

Assignees

• Yamaguchi Shinichi
• Shimadzu Corp

Inventors

• Yamaguchi Shinichi

Classifications

• G01N27/62 Primary

  by investigating the ionisation of gases, e.g. aerosols; by investigating electric discharges, e.g. emission of cathode · CPC title

• H01J49/044

  with means for preventing droplets from entering the analyzer; Desolvation of droplets · CPC title

• H01J49/165

  Electrospray ionisation · CPC title