Ionizing analysis apparatus

• US 5,945,678 A
• Filed: 05/20/1997
• Issued: 08/31/1999
• Est. Priority Date: 05/21/1996
• Status: Expired due to Fees

• Current Assignee: Hamamatsu Photonics KK
• Original Assignee: Hamamatsu Photonics KK
• Inventors: Yanagisawa, Yutaro
• Primary Examiner(s): Anderson, Bruce C.
• Application Number:
  US08/858,973
• Time in Patent Office: 833 Days
• Field of Search: 250/423 R, 250/423 F, 250/288, 250/287
• US Class Current: 250/423.00F
• CPC Class Codes: H01J 49/168 field ionisation, e.g. corona discharge atmospheric pressure corona discharge per se H01T19/00

Abstract

A needle (22) adapted to advance and retract in z directions is accommodated in an ionization chamber (15), whereas an electrolytic solution (L) containing a sample is supplied into the ionization chamber (15) through a supply tube (18). The supply tube (18) is bored with a hole (20) communicating with the inside of the ionization chamber (15). While a predetermined voltage is applied between the supply tube (18) and the needle (22), the tip of the needle (22) is caused to come close to but not in contact with the electrolytic solution in the hole (20), so as to form a locally raised portion (Taylor cone) in the liquid surface of the electrolytic solution, thereby attaching a droplet containing ions in the electrolytic solution to the tip of the needle (22). After the needle (22) is moved to a predetermined position, N₂ gas is jetted against the tip portion of the needle (22), thereby emitting the droplet containing ions attached to the tip of the needle (22) into the ionization chamber (15). Accordingly, the ions can be concentrated and subjected to soft ionization. Thus, an analysis apparatus for improving the ion generating efficiency to be used for mass spectrometry or the like is provided.

Claims

1. An ionizing analysis apparatus which ionizes a sample material contained in an electrolytic solution in a chamber, emits thus obtained ion, and then detects thus emitted ion, said apparatus comprising:

a supply tube which supplies the electrolytic solution into said chamber and has an opening within said chamber;

a needle having a tip disposed so as to oppose to said opening within said chamber;

a nozzle for jetting out a gas against any region between the tip of said needle and said opening from a direction substantially orthogonal to a longitudinal direction of said needle;

takeout means for taking out a droplet of said electrolytic solution by said needle; and

emitting means for emitting the droplet is into said chamber by the gas jetting out from said nozzle against the droplet taken out by said takeout means or said needle having the tip to which the droplet is attached.

2. An ionizing analysis apparatus according to claim 1, wherein said emitting means further comprises means for applying a predetermined voltage to said needle, said predetermined voltage corresponding to a charge polarity of the ion in said droplet taken out.

3. An ionizing analysis apparatus according to claim 1, wherein said emitting means further comprises means for intermittently emitting the gas.

4. An ionizing analysis apparatus according to claim 1, further comprising a skimmer disposed in said chamber so as to oppose to said nozzle across said needle and opening, said skimmer having an opening portion substantially at the center thereof and a gas emitting port, said gas emitting port being disposed around said opening portion so as to be directed toward said nozzle.

5. An ionizing analysis apparatus according to claim 1, wherein said takeout means further comprises means for applying, between said needle and said opening, a predetermined voltage opposite to a charge polarity of the ion in said electrolytic solution.

6. An ionizing analysis apparatus according to claim 1, wherein said takeout means further comprises means for generating a Taylor cone by vibrating said tube so as to vibrate a liquid surface of said opening.

7. An ionizing analysis apparatus according to claim 1, wherein said takeout means further comprises means for bringing a liquid surface of said opening into contact with the tip of said needle by vibrating said tube so as to vibrate said liquid surface.

8. An ionizing analysis apparatus according to claim 1, wherein said takeout means further comprises means for temporarily bringing the tip of said needle into contact with or close to said electrolytic solution by moving said needle in the longitudinal direction thereof.

9. An ionizing analysis apparatus according to claim 1, wherein said takeout means further comprises vibrating means for vibrating said needle so as to temporarily bring the tip of said needle into contact with or close to said electrolytic solution.

10. An ionizing analysis apparatus according to claim 9, wherein said vibrating means is a ultrasonic vibrator.

11. An ionizing analysis apparatus according to claim 1, wherein at least a portion of the surface of said needle is coated with a material selected from the group consisting of dielectric materials, insulating materials, materials repellent to the electrolytic solution, and materials absorbing the electrolytic solution.

12. An ionizing analysis apparatus according to claim 1, wherein said needle has a constricted portion near a tip portion between the tip of said needle and a base portion of said needle.

13. An ionizing analysis apparatus which ionizes a sample material contained in an electrolytic solution in a chamber, emits thus obtained ion, and then detects thus emitted ion, said apparatus comprising:

a supply tube which supplies said electrolytic solution into said chamber and has an opening within said chamber;

a needle which is disposed in said tube, has a tip projecting into said chamber through said opening, and is movable in a longitudinal direction thereof; and

a nozzle for jetting out a gas against the tip of said needle from a direction substantially orthogonal to the moving direction of said needle.

14. An ionizing analysis apparatus according to claim 13, further comprising means for applying a predetermined voltage to said needle, said predetermined voltage corresponding to a charge polarity of the ion in said electrolytic solution.

15. An ionizing analysis apparatus according to claim 13, further comprising means for intermittently emitting said gas.

16. An ionizing analysis apparatus according to claim 13, further comprising a skimmer disposed in said chamber so as to oppose to said nozzle across said needle and opening, said skimmer having an opening portion substantially at the center thereof and a gas emitting port, said gas emitting port being disposed around said opening portion so as to be directed toward said nozzle.

17. An ionizing analysis apparatus according to claim 13, further comprising means for applying a predetermined voltage to said needle, said predetermined voltage having a polarity opposite to a charge polarity of the ion in said electrolytic solution.

18. An ionizing analysis apparatus according to claim 13, further comprising means for generating a Taylor cone by vibrating said tube so as to vibrate a liquid surface of said opening.

19. An ionizing analysis apparatus according to claim 13, further comprising means for bringing a liquid surface of said opening into contact with the tip of said needle by vibrating said tube so as to vibrate said liquid surface.

20. An ionizing analysis apparatus according to claim 13, further comprising means for temporarily bringing the tip of said needle into contact with or close to said electrolytic solution by moving said needle in the longitudinal direction thereof.

21. An ionizing analysis apparatus according to claim 13, further comprising vibrating means for vibrating said needle so as to temporarily bring the tip of said needle into contact with or close to said electrolytic solution.

22. An ionizing analysis apparatus according to claim 21, wherein said vibrating means is a ultrasonic vibrator.

23. An ionizing analysis apparatus according to claim 13, wherein at least a portion of the surface of said needle is coated with a material selected from the group consisting of dielectric materials, insulating materials, materials repellent to the electrolytic solution, and materials absorbing the electrolytic solution.

24. An ionizing analysis apparatus according to claim 13, wherein said needle has a constricted portion near a tip portion between the tip of said needle and a base portion of said needle.

25. An ionizing analysis apparatus which ionizes a sample material contained in an electrolytic solution in a chamber, emits thus obtained ion, and then detects thus emitted ion, said apparatus comprising:

a supply tube which supplies said electrolytic solution into said chamber and has an opening within said chamber;

a first needle in which at least a tip thereof is disposed within said chamber;

a second needle which has a tip opposed to the tip of said first needle and is disposed within said tube so as to be relatively movable with respect to said first needle; and

a nozzle for jetting out a gas against the tip of said second needle from a direction substantially orthogonal to the moving direction of said second needle.

26. An ionizing analysis apparatus according to claim 25, further comprising means for applying a predetermined voltage to said first needle, said predetermined voltage corresponding to a charge polarity of the ion in said electrolytic solution.

27. An ionizing analysis apparatus according to claim 25, further comprising means for intermittently emitting said gas.

28. An ionizing analysis apparatus according to claim 25, further comprising a skimmer disposed in said chamber so as to oppose to said nozzle across said first and second needles, said skimmer having an opening portion substantially at the center thereof and a gas emitting port, said gas emitting port being disposed around said opening portion so as to be directed toward said nozzle.

29. An ionizing analysis apparatus according to claim 25, further comprising means for applying a predetermined voltage between said first and second needles, said predetermined voltage having a polarity opposite to a charge polarity of the ion in said electrolytic solution.

30. An ionizing analysis apparatus according to claim 25, further comprising means for temporarily bringing the tip of said first needle into contact with or close to said electrolytic solution by moving said first needle in a longitudinal direction thereof.

31. An ionizing analysis apparatus according to claim 25, further comprising vibrating means for vibrating said first and second needles so as to temporarily bring the tip of said first needle into contact with or close to said electrolytic solution.

32. An ionizing analysis apparatus according to claim 31, wherein said vibrating means is a ultrasonic vibrator.

33. An ionizing analysis apparatus according to claim 25, wherein at least a portion of the surfaces of said first and second needles is coated with a material selected from the group consisting of dielectric materials, insulating materials, materials repellent to the electrolytic solution, and materials absorbing the electrolytic solution.

34. An ionizing analysis apparatus according to claim 25, wherein said first needle has a constricted portion near a tip portion between the tip of said first needle and a base portion of said first needle.

35. An ionizing analysis apparatus which ionizes a sample material contained in an electrolytic solution in a chamber, emits thus obtained ion, and then detects thus emitted ion, said apparatus comprising:

a supply tube which supplies the electrolytic solution into said chamber and has an opening within said chamber;

a needle disposed within said chamber;

takeout means for taking out a droplet of said electrolytic solution by said needle, wherein said takeout means comprises means for generating a Taylor cone by vibrating said supply tube so as to vibrate a liquid surface of said opening; and

emitting means for emitting said droplet into said chamber by gas jetting out against said droplet taken out by said takeout means preferably with applying a predetermined voltage, corresponding to a charge polarity of said ion in said droplet taken out, to said needle.

36. An ionizing analysis apparatus which ionizes a sample material contained in an electrolytic solution in a chamber, emits thus obtained ion, and then detects thus emitted ion, said apparatus comprising:

a supply tube which supplies the electrolytic solution into said chamber and has an opening within said chamber;

a needle having a tip disposed within said chamber;

takeout means for taking out a droplet of said electrolytic solution by said needle wherein said takeout means comprises means for bringing a liquid surface of said opening into contact with said tip of said needle by vibrating said supply tube so as to vibrate said liquid surface; and

emitting means for emitting said droplet into said chamber by gas jetting out against said droplet taken out by said takeout means preferably with applying a predetermined voltage, corresponding to a charge polarity of said ion in said droplet taken out, to said needle.