| Title: |
Reflector Time-of-Flight Mass Spectrometry with Simultaneous Space and Velocity Focusing |
| Document Number: |
20120145889 |
| Publication Date: |
June 14, 2012 |
| Appl. No: |
13/034525 |
| Application Filed: |
February 24, 2011 |
| Abstract: |
A time-of-flight mass spectrometer includes an ion source that generates ions. A two-field ion accelerator accelerates the ions through an ion flight path. A pulsed ion accelerator focuses the ions to a first focal plane where the ion flight time is substantially independent to first order of an initial velocity of the ions prior to acceleration. An ion reflector focuses ions to a second focal plane where the ion flight time is substantially independent to first order of an initial velocity of the ions prior to acceleration. An ion detector positioned at the second focal plane detects the ions. The two-field ion accelerator and the ion reflector cause the ion flight time to the ion detector for the ion of predetermined mass-to-charge ratio to be substantially independent to first order of both the initial position and the initial velocity of the ions prior to acceleration. |
| Inventors: |
Vestal, Marvin L. (Framingham, MA, US) |
| Assignees: |
VIRGIN INSTRUMENTS CORPORATION (Sudbury, MA, US) |
| Claim: |
1. A time-of-flight mass spectrometer comprising: a. an ion source that generates ions; b. a two-field ion accelerator having an input that receives the ions generated by the ion source, the two-field ion accelerator generating an electric field that accelerates the ions generated by the ion source through an ion flight path; c. a pulsed ion accelerator positioned in the ion flight path adjacent to the two-field ion accelerator, the pulsed ion accelerator generating an accelerating electric field that focuses the ions to a first focal plane where the ion flight time to the first focal plane for an ion of predetermined mass-to-charge ratio is substantially independent to first order of an initial velocity of the ions prior to the acceleration; d. an ion reflector positioned in the ion flight path that focuses ions to a second focal plane where the ion flight time to the second focal plane for an ion of predetermined mass-to-charge ratio is substantially independent to first order of an initial velocity of the ions prior to the acceleration; and e. an ion detector positioned at the second focal plane for detecting ions, the two-field ion accelerator and the ion reflector generating electric fields that cause the ion flight time to the ion detector for the ion of predetermined mass-to-charge ratio to be substantially independent to first order of both the initial position and the initial velocity of the ions prior to the acceleration. |
| Claim: |
2. The mass spectrometer of claim 1 wherein the ion reflector comprises a two-field ion reflector. |
| Claim: |
3. The mass spectrometer of claim 1 wherein the ion source comprises a pulsed ion source and a first field generated by the two-field ion accelerator comprises a static accelerating electric field. |
| Claim: |
4. The mass spectrometer of claim 1 wherein the ion source comprises a continuous source and a first field generated by the two-field ion accelerator comprises a pulsed accelerating electric field. |
| Claim: |
5. The mass spectrometer of claim 4 wherein the ion source comprises an external ionization source. |
| Claim: |
6. The mass spectrometer of claim 4 wherein the ion source comprises an electrospray ionization source. |
| Claim: |
7. The mass spectrometer of claim 4 wherein the ion source comprises an electron beam source. |
| Claim: |
8. The mass spectrometer of claim 4 wherein the ion source comprises a primary ion beam source. |
| Claim: |
9. The mass spectrometer of claim 4 wherein the ion source comprises a chemical ionization source. |
| Claim: |
10. The mass spectrometer of claim 1 wherein the sample is positioned on a solid surface. |
| Claim: |
11. The mass spectrometer of claim 10 wherein the ion source comprises a pulsed laser. |
| Claim: |
12. The mass spectrometer of claim 10 wherein the ion source comprises a MALDI ion source. |
| Claim: |
13. The mass spectrometer of claim 1 further comprising a timed ion selector positioned in the ion flight path adjacent to the pulsed ion accelerator, the timed ion selector transmitting ions accelerated by the pulsed ion accelerator and preventing all other ions from passing. |
| Claim: |
14. The mass spectrometer of claim 1 further comprising an ion lens positioned in the ion flight path between the two-field ion accelerator and the pulsed accelerator, the ion lens spatially focusing the ions to the ion detector. |
| Claim: |
15. The mass spectrometer of claim 1 further comprising at least one ion steering electrode positioned in the ion flight path between the two-field ion accelerator and the pulsed accelerator. |
| Claim: |
16. A method for generating high resolution mass spectra by time-of-flight mass spectrometry, the method comprising: a. generating a pulse of ions from a sample; b. accelerating the pulse of ions with a first and second electric field; c. further accelerating the pulse of ions accelerated by the first and second electric fields with a pulsed electric field that focuses ions to a first focal plane where an ion flight time to the first focal plane for an ion of predetermined mass-to-charge ratio is substantially independent to first order of an initial velocity of the ions prior to the acceleration; d. adjusting the first and second electric fields to cause the ion flight time to the first focal plane for ions of the predetermined mass-to-charge ratio to be independent to first order of both an initial position and an initial velocity of the ions prior to the acceleration; e. reflecting ions with an ion reflector to a second focal plane where ions having the predetermined mass-to-charge ratio are independent to first order of both the initial position and the initial velocity of the ions prior to the acceleration; and f. detecting ions at the second focal plane. |
| Claim: |
17. The method of claim 16 wherein the sample comprises a MALDI sample. |
| Claim: |
18. The method of claim 16 wherein the generating the pulse of ions comprises irradiating the sample with a pulsed laser. |
| Claim: |
19. The method of claim 16 further comprising selecting ions from the pulse of ions after the accelerating the pulse of ions with the pulsed electric field and passing only selected ions. |
| Claim: |
20. The method of claim 16 further comprising spatially focusing ions in the ion flight path after acceleration by the first and the second electric fields to the first focal plane. |
| Claim: |
21. The method of claim 16 further comprising steering ions in the ion flight path after the accelerating the pulse of ions with the first and second electric field. |
| Claim: |
22. The method of claim 16 wherein the generating the pulse of ions comprises generating the pulse of ions with a pulsed ion source and wherein the first electric field comprises a static electric field. |
| Claim: |
23. The method of claim 16 wherein the generating the pulse of ions comprises generating the pulse of ions with a continuous ion source and wherein the first electric field comprises a pulsed accelerating electric field. |
| Current U.S. Class: |
250/282 |
| Current International Class: |
01 |
| Accession Number: |
edspap.20120145889 |
| Database: |
USPTO Patent Applications |
