Collision ion generator and separator

Patent metadata

Field	Value
Publication number	US-9287100-B2
Application number	US-201214368797-A
Country	US
Kind code	B2
Filing date	Dec 28, 2012
Priority date	Dec 28, 2011
Publication date	Mar 15, 2016
Grant date	Mar 15, 2016

Abstract

According to some embodiments, systems and methods for surface impact ionization of liquid phase and aerosol samples are provided. The method includes accelerating a liquid or aerosol sample, colliding the sample with a solid collision surface thereby disintegrating the sample into both molecular ionic species (e.g., gaseous molecular ions) and molecular neutral species (e.g., gaseous sample), and transporting the disintegrated sample to an ion analyzer. Some embodiments of the method further comprise discarding the molecular neutral species. Such embodiments transport substantially only the molecular ionic species to the ion analyzer.

First claim

What is claimed is:

1. A method for generating gaseous molecular ions for analysis by a mass spectrometer or ion mobility spectrometer, comprising:
accelerating an aerosol sample toward a solid surface, the sample comprising one or more of molecular particle clusters, solid particles, and neutral particles;
colliding the aerosol sample with the solid surface to disintegrate the one or more molecular particle clusters and to generate one or more of gaseous molecular ions, neutral molecules and smaller-sized molecular particle clusters; and
collecting the gaseous molecular ions and directing the gaseous molecular ions to an analyzer unit.

2. The method of claim 1 , further comprising analyzing the gaseous molecular ions to provide information on the chemical composition of the sample.

3. The method of claim 1 , wherein collecting comprises collecting the gaseous molecular ions with a skimmer electrode generally aligned with an opening through which the sample is introduced.

4. The method of claim 1 , wherein accelerating the sample comprises driving the sample via a pressure gradient along a tubular opening through which the sample is introduced.

5. The method of claim 4 , wherein accelerating the sample further comprises establishing an electrical potential gradient between the tubular opening and the solid surface.

6. The method of claim 5 , wherein one of a positive electrical and a negative electrical potential is applied to the solid surface.

7. The method of claim 1 , wherein accelerating the sample comprises accelerating the sample above sonic speed in a free jet expansion.

8. The method of claim 1 , wherein collecting the gaseous molecular ions comprises separating the gaseous molecular ions from the neutral molecules and smaller-sized molecular particle clusters.

9. The method of claim 8 , wherein separating comprises generating turbulence along at least a portion of the collision element, said turbulence allowing the gaseous molecular ions to separate from the neutral molecules and smaller-sized molecular particle clusters.

10. The method of claim 1 , further comprising heating the solid surface via one of contact heating, resistive heating and radiative heating.

11. The method of claim 1 , wherein the solid surface is a generally spherical surface.

12. The method of claim 11 , wherein said solid surface is disposed in an ion funnel type mass spectrometric atmospheric interface, said ion funnel configured to collect the gaseous molecular ions.

13. The method of claim 11 , wherein said solid surface is disposed between an opening through which the sample is introduced and a skimmer electrode.

14. The method of claim 1 , wherein the solid surface is a generally conical surface.

15. The method of claim 1 , wherein the solid surface is a generally tubular surface of a skimmer electrode.

16. The method of claim 1 , wherein the disintegration of the one or more molecular particle clusters is purely mechanical, driven by the kinetic energy of the particles in the sample.

17. The method of claim 1 , further comprising separating the neutral molecules and smaller-sized molecular particle clusters from the gaseous molecular ions based on mass using a skimmer electrode that allows collection and direction of substantially only the gaseous molecular ions.

18. The method of claim 1 , further comprising separating an ion of interest from the gaseous molecular ions based on one or more of mass and charge using a skimmer electrode that allows collection and direction of substantially only the ion of interest to the analyzer unit.

19. A system for generating gaseous molecular ions for analysis by a mass spectrometer or ion mobility spectrometer, comprising:
a tubular conduit configured to accelerate a sample therethrough, the sample comprising one of an aerosol sample and a liquid sample and having one or more of molecular particle clusters, solid particles and charged particles;
a collision element spaced apart from an opening of the tubular conduit and generally aligned with an axis of the tubular conduit, the collision element having a surface upon which the sample collides, thereby disintegrating the one or more molecular particle clusters to form one or more of gaseous molecular ions, neutral molecules and smaller-sized molecular particle clusters; and
a skimmer electrode configured to collect substantially only the gaseous molecular ions and exclude the neutral molecules and smaller-sized molecular particle clusters, wherein the exclusion is based substantially on one or more of mass and charge of the neutral molecules and smaller-sized molecular particle clusters, the skimmer electrode having an opening generally aligned with the tubular conduit opening such that the collision element is interposed between the tubular conduit opening and the skimmer electrode.

20. The system of claim 19 , further comprising an analyzer configured to analyze the gaseous molecular ions collected by the skimmer electrode to provide information on the chemical composition of the sample.

21. The system of claim 19 , wherein the tubular conduit is configured to direct a substantially continuous liquid jet onto the surface of the collision element.

22. The system of claim 19 , further comprising a vacuum source configured to generate a vacuum between the tubular conduit and the collision element to create a pressure gradient along the tubular conduit that causes the sample to accelerate onto the surface of the collision element.

23. The system of claim 22 , further comprising a power source configured to establish an electrical potential gradient between the tubular conduit opening and the surface of the collision element, said electrical potential gradient further accelerating the sample onto the surface of the collision element.

24. The method of claim 23 , wherein one of a positive electrical and a negative electrical potential is applied to the collision element.

25. The system of claim 22 , wherein the sample is accelerated above sonic speed in a free jet expansion.

26. The system of claim 19 , wherein one or more of the collision element and the skimmer electrode is configured to separate the gaseous molecular ions from the neutral molecules and smaller-sized molecular particle clusters.

27. The system of claim 26 , wherein turbulence along at least a portion of the collision element surface facilitates the separation of the gaseous molecular ions from the neutral molecules and smaller-sized molecular particle clusters.

28. The system of claim 19 , further comprising a heating source chosen from the group consisting of a contact heating source, a resistive heating source and a radiative heating source, the heating source configured to heat the collision element surface.

29. The system of claim 19 , wherein the collision element surface is a generally spherical surface.

30. The system of claim 19 , wherein the collision element surface is a generally conical surface.

31. The method of claim 19 , wherein the disintegration of the one or more molecular particle clusters is purely mechanical, driven by the kinetic energy of the particles in the sample.

32. The method of claim 19 , wherein the tubular conduit is configured to cause the sample to undergo free jet expansion.

33. A system fo

Assignees

• Micromass Ltd

Inventors

• Szalay Daniel
• Godorhazy Lajos
• Takats Zoltan

Classifications

• H01J49/16

  using surface ionisation, e.g. field-, thermionic- or photo-emission · CPC title

• H01J49/14

  using particle bombardment, e.g. ionisation chambers · CPC title

• H01J49/0445

  with means for introducing as a spray, a jet or an aerosol (electrospray ion sources H01J49/165) · CPC title

• H01J49/0031 Primary

  Step by step routines describing the use of the apparatus (H01J49/0081 takes precedence) · CPC title

• H01J49/0454 Primary

  with means for vaporising using mechanical energy, e.g. by ultrasonic vibrations · CPC title