ION DETECTOR AND SYSTEM

• US 20090218238A1
• Filed: 02/28/2008
• Published: 09/03/2009
• Est. Priority Date: 02/28/2008
• Status: Active Grant

• Current Assignee: Dionex Corporation (Thermo Fisher Scientific Incorporated), Board of Regents of the University of Texas System (University of Texas System)
• Original Assignee: Dionex Corporation (Thermo Fisher Scientific Incorporated)
• Inventors: Srinivasan, Kannan, Dasgupta, Purnendu K., Yang, Bingcheng
• Granted Patent: US 8,293,099 B2
• Time in Patent Office: Days
• US Class Current: 205/789
• CPC Class Codes: G01N 30/64 Electrical detectors
• CPC Class Codes: G01N 30/96 using ion-exchange G01N30/02, G01N30/90 take precedence
• CPC Class Codes: Y02E 60/36 Hydrogen production from non-carbon containing sources, e.g. by water electrolysis

Abstract

Apparatus and method for detecting current or potential generated in a liquid sample suitable for use in a chromatography or other liquid sample analytical system. One embodiment is an electrolytic ion transfer device with a signal detector in communication with the electrodes of the transfer device. Another is a combination ion transfer device/electrolyte generator. Another substitutes a detector for the ion transfer device in the combination.

Claims

1. Apparatus for detecting current or potential generated by ionic species in a sample solution containing such ions, said apparatus comprising:

(a) an electrolytic ion transfer device including

(1) a sample flow-through channel having an inlet and an outlet,

(2) a first charged barrier disposed along said sample flow-through channel in fluid contact therewith, said first charged barrier being capable of passing ions of one charge, positive or negative, and of blocking bulk liquid flow,

(3) a first chamber disposed on the opposite side of said first charged barrier from said sample flow-through channel, and

(4) first and second electrodes in electrical communication with said first chamber and said sample flow-through channel, respectively; and

(b) an electrical signal detector in electrical communication with said first and second electrodes.

2. The apparatus of claim 1 in which said first charged barrier comprises an ion exchange bead having exchangeable ions.

3. The apparatus of claim 1 in which said first charged barrier comprises an ion exchange membrane having exchangeable ions.

4. The apparatus of claim 1 in which said electrical signal detector comprises a current meter.

5. The apparatus of claim 4 further comprising:

(5) a second charged barrier along said flow-through channel in fluid communication therewith spaced from said first charged barrier and capable of passing ions of one charge, positive or negative, and

(6) a second chamber disposed on the opposite side of said second charged barrier from said sample flow-through channel.

6. The apparatus of claim 5 in which the exchangeable ions of said first charged barrier are of opposite charge to the exchangeable ions of said second charged barrier.

7. The apparatus of claim 5 in which the exchangeable ions of said first barrier are of the same charge as the exchangeable ions of said second barrier.

8. The apparatus of claim 1 further comprising:

(c) a chromatography column having an inlet and an outlet, said chromatography outlet being in fluid communication with said ion transfer device sample flow-through channel.

9. The apparatus of claim 8 further comprising:

(d) an electrolytic suppressor having a suppressor sample channel having an inlet and an outlet, separated from a regenerant channel by a suppressor charged barrier capable of passing ions of one charge, positive or negative, and of blocking bulk liquid flow, said suppressor sample channel inlet being in fluid communication with said chromatography column outlet and said suppressor sample channel outlet being in fluid communication with said sample flow-through channel.

10. The apparatus of claim 8 in which said first chamber comprises a flow-through ion receiving flow channel having an inlet and an outlet, said apparatus further comprising:

(d) a recycle conduit disposed between said sample flow-through channel outlet and said ion receiving flow channel inlet.

11. Apparatus for detecting ions in a sample solution containing such ions, said apparatus comprising:

(a) an electrolytic ion transfer device including

(1) a sample flow-through channel,

(2) a first charged barrier disposed along said sample flow-through channel in fluid contact therewith, said first charged barrier being capable of passing ions of one charge, positive or negative, and of blocking bulk liquid flow,

(3) a first chamber disposed on the opposite side of said first charged barrier from said sample flow-through channel, and

(4) first and second electrodes in electrical communication with said first chamber and said sample flow-through channel, respectively; and

(b) an electrolytic electrolyte generator comprising;

(1) a first electrolyte source reservoir,

(2) a first electrolyte generation chamber,

(3) a first electrolyte charged barrier capable of passing ions of one charge, positive or negative, and of blocking bulk liquid flow, disposed between said first electrolyte source reservoir and said first electrolyte generation chamber, and

(4) third and fourth electrodes in electrical communication with said first and second electrodes, respectively, and with said first electrode source reservoir and said electrolyte generation chamber, respectively, and

(c) a detector for said electrolyte generated in said electrolyte generation chamber in fluid communication therewith.

12. The apparatus of claim 11 in which said electrolytic generator device further comprises

(5) a second electrolyte generator charged barrier along said flow-through channel in fluid communication therewith spaced from said first charged barrier capable of passing ions of one charge, positive or negative, and

(6) a second chamber disposed on the opposite side of said second charged barrier from said sample flow-through channel.

13. The apparatus of claim 12 in which the exchangeable ions of said first electrolyte generator charged barrier are of opposite charge to the exchangeable ions of said second electrolyte generator charged barrier.

14. The apparatus of claim 12 in which the exchangeable ions of said first electrolyte generator charged barrier are of the same charge as the exchangeable ions of said second electrolyte generator barrier.

15. The apparatus of claim 12 in which said first and second electrolyte generator charged barriers comprise ion exchange beads having exchangeable ions of opposite charge to each other.

16. The apparatus of claim 12 in which said first and second electrolyte generator charged barriers comprise ion exchange membranes having exchangeable ions of opposite charge to each other.

17. The apparatus of claim 11 in which said electrolyte generator further comprises

(5) a second electrolyte source reservoir,

(6) a second electrolyte generation chamber, and

(7) a third charged barrier capable of passing ions of one charge, positive or negative, and of blocking bulk liquid flow, disposed between said second electrolyte source reservoir and said second electrolyte generation chamber.

18. Apparatus for detecting current or potential generated by ions in a sample solution comprising:

(a) flow-through ion exchange medium in a housing having an inlet and an outlet,

(b) first and second electrodes disposed to pass an electric current through said ion exchange medium, and

(c) an electric signal detector in electrical communication with said first and second electrodes.

19. The apparatus of claim 18 in which said electrical signal detector comprises a current meter.

20. The apparatus of claim 18 wherein said ion exchange medium comprises chromatography packing and said housing comprises a chromatography column, said apparatus further comprising:

(d) a sample injector in fluid communication with said chromatography column, wherein no ion exchange medium is disposed between said sample injector and said chromatography column.

21. The apparatus of claim 18 in which said housing comprises a suppressor and said ion exchange medium comprises suppressor medium, said apparatus further comprising:

(d) a chromatography column having an inlet and an outlet, said chromatography column outlet being in fluid communication with said suppressor inlet.

22. The apparatus of claim 18 further comprising:

(d) a chromatography column having an inlet and an outlet, said chromatography column outlet being in fluid communication with said flow through ion exchange medium.

23. The apparatus of claim 22 further comprising:

(e) a suppressor having an inlet and an outlet, said chromatography column outlet being in fluid communication with said suppressor inlet and said suppressor outlet being in fluid communication with said flow through ion exchange medium.

24. A method for detecting current or potential generated by ions in a sample solution containing such ions, said method comprising:

(a) providing an electrolytic ion transfer device including a sample flow-through channel, a first charged barrier capable of passing ions of one charge, positive or negative, and of blocking bulk liquid flow disposed along said sample channel in fluid contact therewith, and a first ion receiving chamber disposed on the opposite side of said first barrier from said sample flow through channel,

(b) flowing an aqueous sample stream including sample ionic species through said sample channel to exit as a sample channel effluent,

(c) passing an electric current between first and second electrodes in electric communication with said sample stream in said sample channel and aqueous liquid in said ion receiving chamber, respectively,

(d) transporting at least a portion of the sample stream ions across said first charged barrier into aqueous solution in said first ion receiving chamber under the influence of said electric current, and,

(e) detecting an electrical signal produced by current flowing between said first and second electrodes.

25. The method of claim 24 in which said ion transfer device further comprises a second charged barrier with exchangeable ions capable of passing ions of one charge, positive or negative, disposed along said sample channel in fluid contact therewith said method further comprising:

(f) transporting ions in said aqueous sample stream across said second barrier into aqueous solution in a second ion receiving chamber.

26. The method of claim 24 in which said first charged barrier comprises an ion exchange bead having exchangeable ions.

27. The method of claim 24 in which said first charged barrier comprises an ion exchange membrane having exchangeable ions.

28. The method of claim 24 further comprising:

(f) chromatographically separating sample ionic species in an eluent stream of one charge, positive or negative, to produce a chromatography effluent, and

(g) flowing said chromatography effluent through said sample flow-through channel.

29. The apparatus of claim 28 further comprising:

(h) between steps (f) and (g), flowing said chromatography effluent through a suppressor to suppress said eluent to exit as a suppressor effluent stream, and flowing said suppressor effluent stream through said ion transfer device sample flow channel.

30. The method of claim 24 in which said first ion receiving flow channel includes an inlet and an outlet, said method further comprising recycling said sample channel effluent to said first ion receiving flow channel inlet.

32. The method of claim 28 in which said electrolyte generator further comprises a second electrolyte source reservoir separated from said first electrolyte generation chamber by a third charged barrier, said potential passing between said third and fourth electrodes causing ions to be transported from said second electrolyte source reservoir to said aqueous solution in said first electrode generation chamber.

33. The method of claim 28 further comprising:

(i) flowing the aqueous sample stream from said sample flow channel to said electrolyte generation chamber.

31. A method for detecting ions in a sample solution containing such ions, said method comprising:

(a) providing an electrolytic ion transfer device including a flow-through sample channel, a first charged barrier capable of passing ions of one charge, positive or negative, and of blocking bulk liquid flow disposed along said sample channel in fluid contact therewith, and a first ion receiving chamber disposed on the opposite side of said first barrier from said sample barrier,

(b) flowing an aqueous sample stream including ions through said flow-through said sample channel,

(c) passing an electric current between first and second electrodes in electric communication with said sample stream in said sample channel and aqueous liquid in said ion receiving chamber, respectively,

(d) transporting at least a portion of the sample stream ions across said first charged barrier into aqueous solution in said first ion receiving chamber under the influence of said electric current,

(e) providing an electrolytic electrolyte generator comprising a first electrolyte source reservoir separated from an electrolyte generating chamber by a second charged barrier having exchangeable ions capable of passing ions of one charge, positive or negative,

(f) flowing an aqueous solution through said electrolyte generating chamber,

(g) applying a potential using a common power supply, between said first and second electrodes, and between third and fourth electrodes, in electrical communication with solution in said first electrolyte source reservoir and in said first electrolyte generating chamber, respectively, to pass ions of one charge, positive or negative, through said second charged barrier to generate electrolyte aqueous solution in said first electrolyte generation chamber, and

(h) detecting said generated electrolyte solution.

34. A method for detecting current or potential generated by sample ionic species in a sample solution comprising:

(a) flowing a sample solution including sample ionic species through ion exchange medium,

(b) passing an electric current through said ion exchange medium between first and second electrodes, and

(c) detecting an electric signal produced by current flowing between said first and second electrodes.

35. The method of claim 34 further comprising chromatographically separating said sample ionic species in said ion exchange medium.

36. The method of claim 34 further comprising, prior to step (a):

(c) chromatographically separating said sample ionic species in said sample stream by flowing said sample stream containing eluent through chromatography separation medium to exit as a chromatographic effluent, and

(d) flowing said chromatographic effluent through said ion exchange medium to suppress said eluent.

37. The method of claim 34 further comprising:

(c) chromatographically separating said sample ionic species in said sample stream by flowing said sample stream containing eluent through chromatography separation medium to exit as a chromatographic effluent,

(d) flowing said chromatography effluent through a suppressor to suppress said eluent and exit as a suppressor effluent, and

(e) flowing said suppressor effluent through said ion exchange medium.

38. Apparatus for detecting analyte in a sample solution containing said analyte, said apparatus comprising:

(a) a detector sample flow channel for liquid sample containing analyte,

(b) a signal detector operatively associated with said detector sample flow channel for detecting analyte in liquid sample therein, said signal detector generating an electrical signal in response to the concentration of said analyte,

(c) an electrolytic electrolyte generator comprising (1) a first electrolyte source reservoir, (2) a first electrolyte generation chamber, (3) a first electrolyte charged barrier capable of passing ions of one charge, positive or negative, and of blocking bulk liquid flow, disposed between said first electrolyte source reservoir and said first electrolyte generation chamber, and (4) first and second electrodes in an electrical circuit with electrical communication with said detector generated electric signal, and with said first electrode source reservoir and said electrolyte generation chamber, respectively, and

(d) an electrolyte detector for said electrolyte generated in said electrolyte generation chamber in fluid communication therewith.

39. The apparatus of claim 38 in which said electrolytic generator further comprises

(5) a second electrolyte generator charged barrier along said flow-through channel in fluid communication therewith spaced from said first charged barrier capable of passing ions of one charge, positive or negative, and

(6) a second chamber disposed on the opposite side of said second charged barrier from said sample flow-through channel.

40. The apparatus of claim 38 in which said detector is selected from the group consisting of a conductivity detector, a photomultiplier based detector, diode array detector, and amperometric detector.

41. A method for detecting ions in a sample solution containing such ions, said method comprising:

(a) flowing an aqueous sample stream including analyte through a detector sample flow channel,

(b) detecting the concentration of analyte in said sample flow channel and generating an electrical signal in response to the detected concentration of said analyte,

(c) providing an electrolytic electrolyte generator comprising a first electrolyte source reservoir separated from an electrolyte generating chamber by a second charged barrier having exchangeable ions capable of passing ions of one charge, positive or negative,

(d) flowing an aqueous solution through said electrolyte generating chamber,

(e) passing said generated electrical signal across to first and second electrodes of opposite polarity, in electrical communication with solution in said first electrolyte source reservoir and in said first electrolyte generating chamber, respectively, to pass ions of one charge, positive or negative, through said second charged barrier to generate electrolyte aqueous solution in said first electrolyte generation chamber, and

(f) detecting said generated electrolyte solution.

42. The method of claim 41 in which said electrolyte generator further comprises a second electrolyte source reservoir separated from said first electrolyte generation chamber by a second charged barrier, said current passing between said first and second electrodes causing ions to be transported from said second electrolyte source reservoir to said aqueous solution in said first electrode generation chamber.

43. The method of claim 41 in which said detector is selected from the group consisting of a conductivity detector, a photomultiplier based detector, diode array detector, and amperometric detector.

44. Apparatus for detecting ions in a sample solution containing such ions, said apparatus comprising:

(a) an electrolytic ion transfer device including

(1) a sample flow-through channel,

(2) a first charged barrier disposed along said sample flow-through channel in fluid contact therewith, said first charged barrier being capable of passing ions of one charge, positive or negative, and of blocking bulk liquid flow,

(3) a first chamber disposed on the opposite side of said first charged barrier from said sample flow-through channel, and

(4) first and second electrodes in electrical communication with said first chamber and said sample flow-through channel, respectively;

(b) an electrolytic electrolyte generator having an inlet and an outlet and having third and fourth electrodes in electrical communication with said first and second electrodes, respectively, and

(c) a detector in fluid communication with said electrolyte generator outlet.

45. Apparatus for detecting ions in a sample solution containing such ions, said apparatus comprising:

(a) an electrolytic ion transfer device including

(1) a sample flow-through channel,

(2) a first charged barrier disposed along said sample flow-through channel in fluid contact therewith, said first charged barrier being capable of passing ions of one charge, positive or negative, and of blocking bulk liquid flow,

(3) a first chamber disposed on the opposite side of said first charged barrier from said sample flow-through channel, and

(4) first and second electrodes in electrical communication with said first chamber and said sample flow-through channel, respectively; and

(b) an electrolytic electrolyte generator comprising;

(1) flow-through ion exchange medium, having an inlet and an outlet,

(2) third and fourth electrodes in electrical communication with said first and second electrodes, respectively, and with said ion exchange medium, and

(c) a detector in fluid communication with said ion exchange medium outlet.

46. Apparatus for detecting analyte in a sample solution containing said analyte, said apparatus comprising:

(a) a detector sample flow channel for liquid sample containing analyte,

(b) a signal detector operatively associated with said detector sample flow channel for detecting analyte in liquid sample therein, said signal detector generating an electrical signal in response to the concentration of said analyte,

(c) an electrolytic electrolyte generator comprising flow-through ion exchange medium having an inlet and an outlet, and first and second spaced-apart electrodes disposed adjacent said ion exchange medium to pass an electrical potential through said medium, said first and second electrodes being in electrical communication with said detector generated electrical signal, and

(d) an electrolyte detector in fluid communication with said ion exchange medium outlet.

47. A method for detecting ions in a sample solution containing such ions, said method comprising:

(a) flowing an aqueous sample stream including analyte through a detector sample flow channel,

(b) detecting the concentration of analyte in said sample flow channel and generating an electrical signal in response to the detected concentration of said analyte,

(c) providing an electrolytic electrolyte generator having first and second electrodes in electrical communication with said electrical signal,

(d) passing said generated electrical signal to said first and second electrodes to generate electrolyte aqueous solution, and

(e) detecting electrolyte solution generated in said eluent generator.

48. The method of claim 47 in which said electrolyte generator further comprises ion exchange medium, said method further comprising applying said electrical signal as a potential through said ion exchange medium between said first and second electrodes.