Mass spectrometer

Patent metadata

Field	Value
Publication number	US-9390900-B2
Application number	US-201113574788-A
Country	US
Kind code	B2
Filing date	Jan 21, 2011
Priority date	Jan 25, 2010
Publication date	Jul 12, 2016
Grant date	Jul 12, 2016

Abstract

A mass spectrometer of ionizing a sample by a dielectric barrier discharge under a reduced pressure. An ionization with inconsiderable fragmentation can be carried out highly sensitively by the present invention.

First claim

The invention claimed is:

1. A mass spectrometer comprising:
a first electrode;
a second electrode;
a dielectric portion provided between the first electrode and the second electrode, the dielectric portion configured in a shape of a cylinder, the first electrode provided at an inside of the cylinder, and the second electrode provided at an outside of the cylinder and spaced apart from the first electrode along the longitudinal axis of the dielectric portion, the dielectric portion having:
an introducing portion placed under atmospheric pressure, and
an extracting portion configured to extract a portion of a sample placed in a vacuum pumped chamber,

a power source configured to superimpose an alternating current voltage on one of the first electrode and the second electrode, and configured to ionize the sample by a dielectric barrier discharge generated between the first electrode and the second electrode at a region of the dielectric portion having a pressure greater than or equal to 2 Torr and less than or equal to 300 Torr; and
a mass analyzing portion configured to analyze an ion extracted from the extracting portion.

2. The mass spectrometer according to claim 1 , wherein the dielectric barrier discharge is carried out at a pressure greater than or equal to 4 Torr.

3. The mass spectrometry according to claim 1 , wherein the dielectric barrier discharge is carried out at a pressure greater than or equal to 7 Torr.

4. The mass spectrometry according to claim 1 , wherein the power source is configured to superimpose a direct current voltage on the electrode of the first electrode and the second electrode which is not applied with the alternating current voltage.

5. The mass spectrometer according to claim 1 , wherein the first electrode is configured in an electrode in a shape of a wire, and the second electrode is provided on a side of the extracting portion of the sample in the shape of the wire.

6. The mass spectrometer according to claim 1 , wherein an inner diameter of the cylinder at a portion configured to carry out discharge is larger than an inner diameter of the other portion.

7. The mass spectrometer according to claim 1 wherein the first electrode is provided to cover the inside of the cylinder.

8. The mass spectrometer according to claim 1 , wherein a gas existing at the dielectric portion is air.

9. The mass spectrometer according to claim 1 , further comprising:
an ionization portion for extracting a charged droplet and an ion of a sample solution on a side of the introducing portion of the sample;
wherein the dielectric portion is heated.

10. The mass spectrometer according to claim 1 , wherein
wherein the dielectric barrier discharge is carried out at a pressure greater than 100 Torr and less than or equal to 300 Torr.

11. A mass spectrometer comprising:
a first electrode;
a second electrode;
a dielectric portion provided between the first electrode and the second electrode, the dielectric portion configured in a shape of a cylinder, the first electrode provided at an inside of the cylinder, and the second electrode provided at an outside of the cylinder and spaced apart from the first electrode along the longitudinal axis of the dielectric portion, the dielectric portion having:
an introducing portion placed under atmospheric pressure, and
an extracting portion configured to extract a portion of a sample placed in a vacuum pumped chamber,

a power source of configured to superimpose an alternating current voltage at a frequency greater than or equal to 1 kHz and less than or equal to 300 kHz on one of the first electrode and the second electrode, and configured to ionize the sample by a dielectric barrier discharge generated between the first electrode and the second electrode at a region of the dielectric portion having a pressure greater than or equal to 2 Torr and less than or equal to 300 Torr; and
a mass analyzing portion configured to analyze an ion extracted from the extracting portion.

12. The mass spectrometer according to claim 11 , wherein the frequency is greater than or equal to 1 kHz and less than or equal to 20 kHz.

13. The mass spectrometer according to claim 11 , wherein the alternating current voltage is of a rectangular wave.

14. The mass spectrometer according to claim 11 , wherein the alternating current voltage is of a sine wave.

15. The mass spectrometer according to claim 11 , wherein
wherein the dielectric barrier discharge is carried out at a pressure greater than 100 Torr and less than or equal to 300 Torr.

16. The mass spectrometer according to claim 11 , wherein the first electrode is configured in a shape of a wire, and the second electrode is provided on a side of the extracting portion of the sample.

17. The mass spectrometer according to claim 11 , wherein an inner diameter of the cylinder at a portion configured to carry out discharge is larger than an inner diameter of the other portion.

18. The mass spectrometer according to claim 11 , wherein the first electrode is provided to cover at least a portion of the inside of the cylinder.

Assignees

• Sugiyama Masuyuki
• Hashimoto Yuichiro
• Hasegawa Hideki
• Hitachi High Tech Corp

Inventors

• Sugiyama Masuyuki
• Hashimoto Yuichiro
• Hasegawa Hideki

Classifications

• H01J27/16

  using high-frequency excitation, e.g. microwave excitation · CPC title

• H01J49/105 Primary

  using high-frequency excitation, e.g. microwave excitation, Inductively Coupled Plasma [ICP] · CPC title

• H01J37/32348

  Dielectric barrier discharge · CPC title

• H05H2001/2443

  Electricity · mapped topic

• H05H1/2406

  using dielectric barrier discharges, i.e. with a dielectric interposed between the electrodes · CPC title