Ion source for mass spectrometers

Patent metadata

Field	Value
Publication number	US-9831078-B2
Application number	US-201213688770-A
Country	US
Kind code	B2
Filing date	Nov 29, 2012
Priority date	Jan 27, 2012
Publication date	Nov 28, 2017
Grant date	Nov 28, 2017

Abstract

Ion sources for use in mass spectrometry (MS) systems are described. The ion sources each comprise an ion funnel and an ionization source configured to ionize neutral analyte molecules.

First claim

The invention claimed is:

1. An ion source, comprising:
an ion funnel comprising a first opening at a first end, a second opening at a second end disposed at a distance from the first opening along an axis, and a plurality of electrodes between the first end and the second end, wherein the first opening is configured to receive neutral analyte molecules, and the electrodes are configured to generate a time-dependent electric field for confining ions in a radial direction orthogonal to the axis and to generate a static electric field oriented along the axis for guiding ions toward the second opening; and
an ionization device disposed in the ion funnel and configured to emit electromagnetic radiation or electrons to ionize the neutral analyte molecules in the ion funnel.

2. An ion source as claimed in claim 1 , further comprising an inlet capillary configured to deliver the neutral analyte molecules to the first opening.

3. An ion source as claimed in claim 2 , wherein the inlet capillary is in fluid communication with a gas chromatograph.

4. An ion source as claimed in claim 1 , wherein the ionization device comprises one of: an electromagnetic radiation source and an electron source.

5. An ion source as claimed in claim 4 , wherein the electromagnetic radiation source comprises a vacuum ultraviolet (VUV) source.

6. An ion source as claimed in claim 5 , wherein the VUV source comprises one of: a microplasma VUV source, an excimer VUV source, a direct current (DC) excited gas discharge source, an alternating current (AC) excited gas discharge source, or a laser source.

7. An ion source as claimed in claim 5 , wherein the VUV source is positioned so that photons from the VUV source interact with the neutral analyte molecules inside the ion funnel.

8. An ion source as claimed in claim 7 , wherein the VUV source is a first VUV source, and the ion source further comprises a second VUV source, the first VUV source and the second VUV source each being positioned at an angle relative to an axis of symmetry of the ion funnel.

9. An ion source as claimed in claim 8 , further comprising a third VUV source and a fourth VUV source each positioned so that photons from the second VUV source, the third VUV source and the fourth VUV source interact with the neutral analyte molecules inside the ion funnel.

10. An ion source as claimed in claim 1 , wherein the neutral analyte molecules are provided in a mixture with a solvent vapor or in a carrier gas.

11. An ion source as claimed in claim 4 , wherein the ionization device is a first ionization device and the ion source further comprises a second ionization device.

12. An ion source as claimed in claim 11 , wherein the second ionization device comprises one of an electromagnetic radiation source and an electron source, and the first ionization device is different than from the second ionization device.

13. An ion source as claimed in claim 11 , wherein the second ionization device comprises one of: an electromagnetic radiation source and an electron source and the first ionization device is the same as the second ionization device.

14. An ion source as claimed in claim 11 , wherein the ion source further comprises a third ionization device and a fourth ionization device.

15. An ion source as claimed in claim 14 , wherein the third ionization source comprises one of an electromagnetic radiation source and an electron source and the fourth ionization device comprises one of an electromagnetic radiation source and an electron source.

16. An ion source as claimed in claim 14 , wherein the first ionization device, the second ionization device, the third ionization device and the fourth ionization device are the same type of ionization device.

17. An ion source as claimed in claim 14 , wherein at least one of the first ionization device, the second ionization device, the third ionization device and the fourth ionization device are different.

18. A mass spectrometer comprising the ion source of claim 1 .

19. A mass spectrometer as claimed in claim 18 , further comprising:
a second ion funnel, in tandem with the first ion funnel, comprising a first opening at a first end and
a second opening at a second end, the first opening configured to receive analyte ions from the second end of the first ion funnel.

20. A method of providing ions in a mass spectrometry system, the method comprising:
introducing neutral analyte molecules to a first end of an ion funnel;
providing an ionization device inside the ion funnel;
ionizing the neutral analyte molecules by operating the ionization device to emit electromagnetic radiation or electrons in the ion funnel to form analyte ions;
guiding the analyte ions to a second end of the ion funnel disposed at a distance from the first end along an axis, by operating the ion funnel to generate a time-dependent electric field for confining the analyte ions in a radial direction orthogonal to the axis and to generate a static electric field oriented along the axis.

21. A method as claimed in claim 20 , wherein the introducing neutral analyte molecules comprises providing neutral analyte molecules in a vapor comprising a solvent or carrier gas.

22. A method as claimed in claim 20 , wherein the introducing neutral analyte molecules comprises providing a solid comprising the analyte molecules.

23. A method as claimed in claim 20 , wherein the ionizing comprises directing electromagnetic radiation, or electrons, or metastable atoms, or stable ions, or a combination thereof at the neutral analyte molecules.

24. A method as claimed in claim 23 , wherein electromagnetic radiation has a wavelength in the vacuum ultraviolet (VUV) spectrum.

25. An ion source as claimed in claim 8 , wherein the second VUV source is positioned inside the ion funnel.

26. An ion source, comprising:
an ion funnel comprising a first opening at a first end, a second opening at a second end disposed at a distance from the first opening along an axis, and a plurality of electrodes between the first end and the second end, wherein the first opening is configured to receive neutral analyte molecules, and the electrodes are configured to generate a time-dependent electric field for confining ions in a radial direction orthogonal to the axis and to generate a static electric field oriented along the axis for guiding ions toward the second opening; and
a VUV source configured to emit VUV photons, the VUV source disposed outside and along a side of the ion funnel, the VUV source being disposed adjacent to an opening in the side of the ion funnel, and being configured to ionize the neutral analyte molecules in the ion funnel.

27. An ion source as claimed in claim 26 , wherein the VUV source is a first VUV source, and the ion source further comprises a second VUV source configured to emit VUV photons, the second VUV source disposed outside and along another side of the ion funnel, the second VUV source being disposed adjacent to another opening in the other side of the ion funnel, and being configured to ionize the neutral analyte molecules in the ion funnel.

Assignees

• Agilent Technologies Inc

Inventors

• Land Adrian
• Hansen Stuart C

Classifications

• H01J49/10 Primary

  Ion sources; Ion guns · CPC title

• H01J49/162

  Direct photo-ionisation, e.g. single photon or multi-photon ionisation · CPC title

• H01J49/107 Primary

  Arrangements for using several ion sources · CPC title

• H01J49/147

  with electrons, e.g. electron impact ionisation, electron attachment (H01J49/145 takes precedence) · CPC title

• H01J49/26

  Mass spectrometers or separator tubes · CPC title