SAMPLING SYSTEM FOR USE WITH SURFACE IONIZATION SPECTROSCOPY

• US 20100102222A1
• Filed: 01/06/2010
• Published: 04/29/2010
• Est. Priority Date: 03/03/2006
• Status: Active Grant

• Current Assignee: Bruker Scientific LLC (Bruker Corporation)
• Original Assignee: IonSense, Inc. (Bruker Corporation)
• Inventors: Musselman, Brian D.
• Granted Patent: US 8,217,341 B2
• Time in Patent Office: Days
• US Class Current: 250/288
• CPC Class Codes: G01N 30/7293 Velocity or momentum separators
• CPC Class Codes: H01J 49/04 Arrangements for introducing or extracting samples to be analysed, e.g. vacuum locks; Arrangements for external adjustment of electron- or ion-optical components
• CPC Class Codes: H01J 49/0404 Capillaries used for transferring samples or ions electrospray nozzles H01J49/167
• CPC Class Codes: H01J 49/16 using surface ionisation, e.g. field-, thermionic- or photo-emission

Abstract

In various embodiments of the invention, a device permits more efficient collection and transmission of ions produced by the action of a carrier gas containing metastable neutral excited-state species into a mass spectrometer. In one embodiment of the invention, the device incorporates the source for ionization in combination with a jet separator to efficiently remove excess carrier gas while permitting ions to be more efficiently transferred into the vacuum chamber of the mass spectrometer. In an embodiment of the invention, improved collection of ions produced by the carrier gas containing metastable neutral excited-state species at greater distances from between the position of the analyte and the position of the mass spectrometer are enabled.

Claims

1. A gas ion separator comprising:

(a) an external ionization source;

(b) a plurality of substantially co-axial tubes, wherein the plurality of tubes are spaced such that there is a gap between the plurality of substantially co-axial tubes; and

(c) a vacuum region, wherein at least a portion of one of the plurality of substantially co-axial tubes are located in the vacuum region.

2. The gas ion separator of claim 1, further comprising one or more cages encircling one or more of the gaps between the plurality of substantially co-axial tubes.

3. The gas ion separator of claim 1, further comprising one or more capacitive surface on one or more of the plurality of substantially co-axial tubes, wherein one or more potential are applied to the one or more capacitive surfaces.

4. The gas ion separator of claim 1, wherein one or more of the plurality of substantially co-axial tubes is made of a material selected from the group consisting of glass, resistively coated glass, glass lined metal tube, coated fused silica, metal coated fused silica, machinable glass, metal coated machinable glass, ceramic, metal coated ceramic and metal.

5. The gas ion separator of claim 1, wherein at least one of the plurality of substantially co-axial tubes has a proximal portion and a distal portion, wherein the proximal portion is located in part in a region of approximately atmospheric pressure, wherein the distal portion is located at least in part in a region of approximately high vacuum, such that the at least one substantially co-axial tubes spans between a region of approximately atmospheric pressure and a region of approximately high vacuum.

6. A system for detecting an analyte comprising:

(a) an ionization source;

(b) an inlet side tube having two ends, with one of the ends proximal to the ionization source;

(c) a vacuum region;

(d) an outlet side tube having two ends, with one of the ends distal to the ionization source, wherein the inlet side tube and the outlet side tube are substantially co-axial; and

(e) a detector of the analyte.

7. The system of claim 6, wherein the said detector is selected from the group consisting of mass spectrometer, raman spectrometer, electromagnetic absorption spectrometer, electromagnetic emission spectrometer and surface detection spectrometer.

8. A gas ion separator for introducing ions into a spectrometer comprising:

(a) an external ionization source, wherein one or more ions are formed by the external ionization source; and

(b) a jet separator, wherein one or more ions formed by the external ionization source are transmitted through the jet separator into the spectrometer, wherein the jet separator is made up of an inlet tube having a proximal end and a distal end and an outlet tube having a proximal end and a distal end;

wherein the proximal end of the inlet tube is closest to and the distal end is furthest from the external ionization source, wherein the inlet tube and the outlet tube are substantially co-axial, wherein the inlet tube is positioned in a region of approximately atmospheric pressure, wherein the outlet tube is positioned in a vacuum region.

9. The gas ion separator of claim 8, wherein the vacuum region is between:

a lower limit of approximately 10¹ Torr;

an upper limit of approximately 10² Torr.

10. The gas ion separator of claim 8, wherein the vacuum region is between:

a lower limit of approximately 5×

10<sup>−

6</sup> Torr;

an upper limit of approximately 5×

10<sup>−

3</sup> Torr.

11. The gas ion separator of claim 8, wherein the vacuum region is between:

a lower limit of approximately 5×

10<sup>−

6</sup> Torr;

an upper limit of approximately 5×

10² Torr.

12. The gas ion separator of claim 8, further comprising a heater directed to at least one of the proximal end of the inlet tube, the distal end of the inlet tube, the proximal end of the outlet tube and the distal end of the outlet tube.

13. The gas ion separator of claim 8, wherein the inlet tube and the outlet tube are spaced such that there is a gap between the inlet tube and the outlet tube, wherein a vacuum generates the vacuum region and is applied to the gap.

14. The gas ion separator of claim 13, wherein the vacuum in the vacuum region can be varied to adjust for a specific geometry of the gas ion separator.

15. The gas ion separator of claim 13, wherein the vacuum in the vacuum region can be varied to adjust for the gap between the inlet tube and the outlet tube.

16. The gas ion separator of claim 13, wherein the vacuum in the vacuum region sucks ions into the proximal end of the inlet tube of the gas ion separator.

17. The gas ion separator of claim 13, further comprising a cage encircling the gap between the inlet tube and the outlet tube.

18. An ionization source comprising:

(a) an atmospheric pressure ionization source;

(b) one or more tube, wherein the one or more tube is positioned proximal to the atmospheric ionization source;

(c) a skimmer, wherein the skimmer is positioned distal to the atmospheric ionization source, wherein the one or more tube is positioned such that there is a gap between the skimmer and the tube; and

(d) a vacuum, wherein the vacuum is applied to the gap between the skimmer and the one or more tube.

19. A gas ion separator comprising:

(a) an external ion source;

(b) a vacuum region; and

(c) a jet separator;

wherein the jet separator is made up of an inlet tube having a proximal end and a distal end and an outlet tube having a proximal end and a distal end, wherein the proximal end of the inlet tube is closest to and the distal end is furthest from the external ionization source, wherein the inlet tube and the outlet tube are spaced such that there is a gap, wherein the vacuum region is in contact with the gap.

20. The gas ion separator of claim 19, wherein the inlet tube and the outlet tube are substantially coaxial.

21. The gas ion separator of claim 20, wherein the atmospheric pressure ionization source is a Direct Analysis Real Time (DART) ionization source.