Claims
- 1. A method for selectively delivering ions to a vacuum region comprising the steps of:(a) providing a dielectric conduit having an axial bore originating in an inlet opening contained within an ion source and terminating in an exit opening within the vacuum region; (b) flowing a gas stream through the conduit, said gas stream comprising an ion traveling at a drift velocity through the bore from the inlet opening toward the exit opening; (c) generating an electric field, corresponding to the polarity of the ion and generally opposing gas flow assisted movement of the ion within the conduit; and (d) selectively altering the temperature of the dielectric conduit for selectively altering the drift velocity of the ion, wherein the ion is selectively delivered to the vacuum region.
- 2. The method of claim 1, wherein the ion source is at about atmospheric pressure.
- 3. The method of claim 1, wherein the conduit is a capillary.
- 4. The method of claim 1, wherein the electric field is produced by applying to the conduit a potential difference of absolute magnitude in the range from about 0 V to about 20 kV.
- 5. The method of claim 1, wherein step (d) comprises heating a portion of the dielectric conduit such that heat is transferred to the gas stream.
- 6. The method of claim 1, wherein step (d) comprises changing the temperature of the gas stream before entry into the conduit.
- 7. The method of claim 1, wherein step (d) comprises cooling a portion of the dielectric conduit such that heat is removed from the gas stream.
- 8. The method as recited in claim 1, wherein the electromagnetic radiation has an infrared wavelength.
- 9. The method as recited in claim 1, wherein the electromagnetic radiation has a microwave wavelength.
- 10. A method for selectively delivering ions to a vacuum region comprising the steps of:(a) providing a dielectric conduit having an axial bore originating in an inlet opening contained within an ion source and terminating in an exit opening within the vacuum region; (b) flowing a gas stream through the conduit, said gas stream comprising an ion traveling at a drift velocity through the bore from the inlet opening toward the exit opening; and (c) selectively altering the temperature of the dielectric conduit for selectively altering the drift velocity of the ion, wherein the ion is selectively delivered to the vacuum region.
- 11. A method for selectively delivering ions to a mass analyzer operating in a vacuum region comprising the steps of:(a) providing a dielectric conduit having an axial bore originating in an inlet opening contained within an ion source and terminating in an exit opening within the vacuum region containing the mass analyzer; (b) flowing a gas stream through the conduit, said gas stream comprising an ion traveling at a drift velocity through the bore from the inlet opening toward the exit opening; (c) generating an electric field, corresponding to the polarity of the ion and generally opposing gas flow assisted movement of the ion within the conduit; (d) selectively altering the temperature of the dielectric conduit for selectively altering the drift velocity of the ion, wherein the ion selectively exits the conduit into the vacuum region; and (e) delivering the selected ion to the mass analyzer.
- 12. The method of claim 11, wherein step (d) comprises heating a portion of the dielectric conduit such that heat is transferred to the gas stream.
- 13. The method of claim 11, wherein step (d) comprises changing the temperature of the gas stream before entry into the conduit.
- 14. The method of claim 11, wherein step (d) comprises cooling a portion of the dielectric conduit such that heat is removed from the gas stream.
- 15. A method for selectively delivering ions to a mass analyzer operating in a vacuum region comprising the steps of:(a) providing a dielectric conduit having an axial bore originating in an inlet opening contained within an ion source and terminating in an exit opening within the vacuum region containing the mass analyzer; (b) flowing a gas stream through the conduit, said gas stream comprising an ion traveling at a drift velocity through the bore from the inlet opening toward the exit opening; (c) selectively altering the temperature of the dielectric conduit for selectively altering the drift velocity of the ion, wherein the ion selectively exits the conduit into the vacuum region; and (d) delivering the selected ion to the mass analyzer.
- 16. An apparatus for selectively delivering ions from an ion source to a vacuum region, comprising:(a) a dielectric conduit having an axial bore connecting the ion source and the vacuum region, wherein the gas flows from the ion source to the vacuum region at a drift velocity; and (b) thermal velocity altering means in a contact with the dielectric conduit for selectively altering the temperature of the conduit for altering the drift velocity of the ions, wherein the ions are selectively delivered to the vacuum region.
- 17. The apparatus of claim 16 wherein the ionization source is at about atmospheric pressure.
- 18. The apparatus of claim 16, wherein the velocity altering means comprises a means for heating the dielectric conduit.
- 19. The apparatus of claim 16, wherein the velocity altering means comprises a means for cooling the dielectric conduit.
- 20. An apparatus for selectively delivering ions from an ion source to a vacuum region, comprising:(a) a dielectric conduit having an axial bore connecting the ion source and the vacuum region, wherein the gas flows from the ion source to the vacuum region at a drift velocity; and (b) electric velocity altering means in contact with the dielectric conduit for altering the drift velocity of the ion in a manner that does not substantially depend on the polarity of the ion, wherein the ion is selectively delivered to the vacuum region.
- 21. An apparatus for selectively delivering ions from an ion source to a vacuum region, comprising:(a) a dielectric conduit having an axial bore connecting the ion source and the vacuum region, wherein the gas flows from the ion source to the vacuum region at a drift velocity; and (b) electric velocity altering means in contact with the dielectric conduit for altering the drift velocity of the ion in a manner that does not substantially depend on the polarity of the ion, said electric velocity altering means comprising a periodic, alternating direction electric field applied to the ion to effect trapping of the ion within the conduit, wherein the ion is selectively delivered to the vacuum region.
- 22. The apparatus of claim 21, wherein the periodic, alternating direction electric field varies at a radio frequency.
- 23. The apparatus of claim 21, wherein the electric velocity altering means further comprises at least two alternating voltage electrodes for producing the electric field, each encircling the conduit, and an alternating voltage supply electrically connected to the electrodes.
- 24. The apparatus of claim 23, wherein the alternating voltage supply can provide a range of alternating voltage frequencies.
- 25. The apparatus of claim 23, wherein the alternating voltage supply can provide a range of alternating voltage amplitudes.
- 26. The apparatus of claim 23, wherein the alternating voltage supply can provide alternating pulsed voltages.
- 27. A method for selectively delivering ions to a vacuum region comprising the steps of:(a) providing a dielectric conduit having an axial bore originating in an inlet opening contained within an ion source and terminating in an exit opening within the vacuum region; (b) flowing a gas stream through the conduit, said gas stream comprising an ion traveling at a drift velocity through the bore from the inlet opening toward the exit opening; (c) generating an electric field, corresponding to the polarity of the ion and generally opposing gas flow assisted movement of the ion within the conduit; and (d) subjecting the gas stream to electromagnetic radiation having a wavelength that can be absorbed by the gas stream for raising the temperature of the gas stream and selectively altering the drift velocity of the ion, wherein the ion is selectively delivered to the vacuum region.
- 28. An apparatus for selectively delivering ions from an ion source to vacuum region comprising:(a) a dielectric conduit having an axial bore connecting the ion source and the vacuum region, wherein the gas flows from the ion source to the vacuum region at a drift velocity; and (b) apparatus for selectively heating the gas stream electromagnetic radiation having a wavelength that can be absorbed by the gas stream for selectively altering the drift velocity of the ion, wherein the ion is selectively delivered to the vacuum region.
- 29. The apparatus as recited in claim 28, wherein the electromagnetic radiation has an infrared wavelength.
- 30. The apparatus as recited in claim 28, wherein the electromagnetic radiation has a microwave wavelength.
CROSS REFERENCE TO RELATED APPLICATIONS
This application is a continuation-in-part of U.S. application Ser. No. 09/429,063 filed Oct. 29, 1999, from which application priority is claimed under 35 U.S.C. §120, and which disclosure is hereby incorporated by reference in its entirety.
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Continuation in Parts (1)
|
Number |
Date |
Country |
Parent |
09/429063 |
Oct 1999 |
US |
Child |
09/645050 |
|
US |