RADIO FREQUENCY (RF) ION GUIDE FOR IMPROVED PERFORMANCE IN MASS SPECTROMETERS

• US 20130175440A1
• Filed: 01/06/2012
• Published: 07/11/2013
• Est. Priority Date: 01/06/2012
• Status: Active Grant

• Current Assignee: Agilent Technologies, Inc.
• Original Assignee: Agilent Technologies, Inc.
• Inventors: RISTROPH, Trygve, PERELMAN, Gershon
• Granted Patent: US 8,859,961 B2
• Time in Patent Office: Days
• US Class Current: 250/288
• CPC Class Codes: H01J 3/14 Arrangements for focusing or reflecting ray or beam H01J3/02, H01J3/04 take precedence
• CPC Class Codes: H01J 49/062 Ion guides linear ion traps performing mass selection H01J49/4225, mass filters H01J49/421
• CPC Class Codes: H01J 49/066 Ion funnels
• CPC Class Codes: H01J 49/067 Ion lenses, apertures, skimmers

Abstract

Ion guides for use in mass spectrometry (MS) systems are described. The ion guides are configured to provide a reflective electrodynamic field and a direct current (DC or static) electric field to provide ion beams that are more spatially confined with a comparatively large mass range.

Claims

1. An ion guide, comprising:

a plurality of first electrodes disposed about an axis;

a first opening at a first end of the plurality of first electrodes;

a second opening at a second end of the plurality of first electrodes;

a substrate comprising a plurality of second electrodes disposed thereover, the substrate being disposed substantially orthogonally to the second opening and comprising a third opening that is substantially aligned with the second opening; and

means for applying a radio frequency (RF) voltage between adjacent pairs of the first electrodes, and between adjacent pairs of the second electrodes, wherein the RF voltage creates an ion confining electrodynamic field in a region between the rods and between the electrodes; and

means for applying a direct current (DC) voltage drop between the first opening and the second opening.

2. An ion guide as claimed in claim 1, wherein the first opening has a first area, the second opening has a second area, and the first area is greater than the second area.

3. An ion guide as claimed in claim 2, wherein the third opening has a third area, and the third area is substantially identical to the second area.

4. An ion guide as claimed in claim 1, wherein the first electrodes are rods each having a first end and a second end remote from the first end, the first opening being formed by the first ends, and the second opening being formed by the second ends.

5. An ion guide as claimed in claim 1, wherein the second electrodes are substantially circular in cross section.

6. An ion guide as claimed in claim 1, wherein the second electrodes are substantially parallel to each other.

7. An on guide as claimed in claim 1, wherein the first electrodes are substantially concentric with each other.

8. A mass spectrometry system comprising the ion guide of claim 1.

9. An ion guide, comprising:

a first substrate comprising a first plurality of electrodes disposed thereover;

a second substrate comprising a second plurality of electrodes disposed thereover, the first substrate and the second substrate forming sides of a first opening at a first end and sides of a second opening at a second end, wherein the first opening has a first area and the second opening has a second area that is less than the first area;

means for applying a radio frequency (RF) voltage between adjacent pairs of the first plurality of electrodes, and between adjacent pairs of the second plurality of electrodes, wherein the RF voltage creates an ion confining field in a region between the first and second substrates; and

means for applying a direct current (DC) voltage drop between the first opening and the second opening.

10. An ion guide as claimed in claim 9, wherein the first and second substrates are planar.

11. An ion guide as claimed in claim 9, further comprising a third substrate disposed over a side wall of the ion guide and a fourth substrate disposed over another side wall of the ion guide.

12. An ion guide as claimed in claim 11, wherein the third substrate and the fourth substrate each comprise an electrically conductive material disposed over respective entire surfaces of the third and fourth substrates.

13. An ion guide as claimed in claim 11, wherein the third substrate comprises a third plurality of electrodes disposed thereover and the fourth substrate comprises a fourth plurality of electrodes disposed thereover.

14. An ion guide as claimed in claim 13, further comprising:

means for applying a radio frequency (RF) voltage between adjacent pairs of the third plurality of electrodes, and between adjacent pairs of the fourth plurality of electrodes.

15. An ion guide as claimed in claim 9, wherein the first plurality of electrodes is substantially parallel to each other, and the second plurality of electrodes is substantially parallel to each other.

16. A mass spectrometry system comprising the ion guide of claim 9.

17. An ion guide, comprising:

a substrate comprising a plurality of electrodes disposed thereover, the substrate forming a first opening at a first end and a second opening at a second end, wherein the first opening has a first area and the second opening has a second area that is less than the first area;

means for applying a radio frequency (RF) voltage between adjacent pairs of the plurality of electrodes, wherein the RF voltage creates an field in a region defined by the substrate; and

means for applying a direct current (DC) voltage drop along a length of each of the plurality of electrodes.