System and method for ionization of molecules for mass spectrometry and ion mobility spectrometry

Patent metadata

Field	Value
Publication number	US-10796894-B2
Application number	US-201816186763-A
Country	US
Kind code	B2
Filing date	Nov 12, 2018
Priority date	Sep 2, 2010
Publication date	Oct 6, 2020
Grant date	Oct 6, 2020

Abstract

An ionizing system includes a channel and a heater coupled to the channel. The channel has an inlet disposed in a first pressure region having a first pressure and an outlet disposed in a second pressure region having a second pressure. The first pressure is greater than the second pressure. The heater is for heating the channel, and the channel is configured to generate charged particles of a sample in response to the sample being introduced into the channel.

First claim

What is claimed is:

1. A method, comprising:
receiving neutral particles of a sample in an ionizing region, the ionizing region being disposed along a channel defined by a tube, the tube having a first end disposed in a first pressure region and a second end disposed in a second pressure region, the first pressure region being at a greater pressure than a pressure in the second pressure region thereby providing a pressure differential across the ionizing region;
generating, within the ionizing region and in an absence of an ion source other than the ionizing region itself, charge on at least one of the particles of the sample as the particles are passed in a gas flow along the channel, the charge being generated, at least in part, due to the pressure differential across the ionizing region;
producing one or more gas phase charged molecular ions from the particles of the sample; and
guiding the one or more gas phase charged molecular ions into an analyzer device.

2. The method of claim 1 , wherein the charge on the at least one of the particles of the sample is one of a net negative charge and a net positive charge.

3. The method of claim 1 , wherein the neutral particles of the sample include one or more of an analyte molecule, an analyte molecule associated with a solid matrix particle, and an analyte molecule disposed within a solvent droplet.

4. The method of claim 3 , wherein the sample includes a matrix in 50 to 1,000,000,000,000 times higher mole abundance than the analyte.

5. The method of claim 1 , wherein producing one or more gas phase charged molecular ions includes removing neutral molecules of at least one of a solvent and a matrix from the charged particles of the sample.

6. The method of claim 5 , wherein removing the neutral molecules of the at least one of the solvent and the matrix from the charged particles of the sample includes a collision between the particles of the sample and an obstruction disposed between the first end of the tube and an inlet of the analyzer device.

7. The method of claim 5 , wherein removing the neutral molecules of at least one of the solvent and the matrix from the charged particles occurs through imparting energy into the charged particles by at least one of colliding the charged particles with a solid surface, heating the charged particles, and applying radiofrequency fields to the charged particles.

8. The method of claim 5 , wherein removing the neutral molecules of the at least one of the solvent and the matrix from the charged particles of the sample includes one of subliming and evaporating neutral molecules from the charged particles of the sample.

9. The method of claim 1 , further comprising heating the ionizing region.

10. The method of claim 1 , further comprising analyzing the one or more gas phase charged molecular ions using the analyzer device to derive information of a chemical composition of the sample.

11. The method of claim 1 , wherein the neutral particles of the sample include aerosol particles.

12. The method of claim 11 , wherein the aerosol particles are produced in response to one of laser ablating the sample, impacting the sample with an energy wave, and heating the sample.

13. The method of claim 1 , further comprising releasing one or more singly and multiply charged gas phase analyte ions for analysis in response to neutral matrix molecules being lost from the charged particles of the sample.

14. The method of claim 1 , further comprising receiving a solvent in the channel.

15. The method of claim 1 , wherein the sample includes one or more of an additive selected from the group consisting of acids, bases, and salts and a modifier selected from the group consisting of glycerol and nitrobenzyl alcohol.

16. The method of claim 1 , further comprising receiving one of a matrix or a solvent in the ionizing region, and wherein the particles of the sample include particles of an analyte such that the analyte particles interact with the matrix or the solvent to form molecular ions of the analyte.

17. The method of claim 1 , wherein the first pressure region at the first end of the tube is above atmospheric pressure.

18. The method of claim 1 , wherein the neutral particles of the sample comprise a solvent and an analyte introduced to the channel via a liquid chromatograph, capillary electrophoresis, microdialysis, microfluidics, a liquid junction, or an osmotic flow.

19. The method of claim 18 , wherein the analyte is received from a living organism.

20. The method of claim 1 , wherein receiving neutral particles of the sample includes receiving neutral particles from multiple locations on a surface of a tissue.

21. A system, comprising:
a tube having a first end and a second end, the tube defining a channel extending from the first end to the second end;
a device for creating a pressure differential across the tube such that a pressure at the first end of the tube is greater than a pressure at the second end of the tube; and
an analyzer device having an inlet in fluid communication with the second end of the tube,
wherein the channel includes an ionizing region in which neutral particles of a sample are received and moved through the channel in a gas flow, wherein one or more gas phase charged molecular ions are generated from the neutral particles of the sample prior to the particles reaching the inlet of the analyzer device due, at least in part, to the pressure differential as the particle moves through the channel, and wherein the one or more gas phase charged molecular ions are generated without the use of an ion source other than the channel itself.

22. The system of claim 21 , further comprising an obstruction disposed along an axis defined by the channel, wherein the obstruction includes an impact surface for removing at least one of a solvent and a matrix from the charged particles of the sample.

23. The system of claim 21 , further comprising a heater for heating at least one of the tube and the ionizing region.

24. The system of claim 21 , further comprising an ion funnel device disposed adjacent to the inlet of the analyzer device for focusing one or more of gas-phase ions and charged particles exiting the channel into the analyzer device.

25. The system of claim 21 , wherein the length of the tube is configured to allow remote sampling.

26. The system of claim 21 , further comprising a device for introducing the sample into the tube, wherein the device for introducing the sample into the tube is selected from the group consisting of a substrate, a plate, a melting point tube, a microscopy slide, a spatula, a needle, a syringe, a capillary tube, and a fused silica tube.

27. The system of claim 21 , further comprising a surface adjacent to the first end of the tube, the surface configured to be heated such that, during operation, material ejected from the surface enters the ionizing region as one of droplets and particles.

28. The system of claim 21 , wherein the system is portable.

29. A system, comprising:
an ionizing apparatus, the ionizing apparatus including:
an analyzer device having an inlet;
a tube having a first end and a second end, the tube defining a channel extending from the first end to the second end, wherein the channel defines an ionizing region in which net neutral particles of a sample are received and become electrically charged, at leas

Assignees

• Univ Of The Sciences In Philadelphia
• Univ Wayne State

Inventors

• Trimpin Sarah
• Mcewen Charles Nehemiah
• Pagnotti Vincent Salvatore

Classifications

• H01J49/0404

  Capillaries used for transferring samples or ions (electrospray nozzles H01J49/167) · CPC title

• H01J49/10 Primary

  Ion sources; Ion guns · CPC title

• H01J49/0468

  with means for heating or cooling the sample · CPC title