Continuous electrolytically regenerated packed bed suppressor for ion chromatography

• US 6,508,985 B2
• Filed: 06/08/2001
• Issued: 01/21/2003
• Est. Priority Date: 02/26/1998
• Status: Expired due to Term

• Current Assignee: Dionex Corporation (Thermo Fisher Scientific Incorporated)
• Original Assignee: Dionex Corporation (Thermo Fisher Scientific Incorporated)
• Inventors: Riviello, John M., Liu, Yan, Avdalovic, Nebojsa, Small, Hamish, Srinivasan, Kannan
• Primary Examiner(s): LUDLOW, JAN M
• Application Number:
  US09/877,666
• Publication Number:
  US 20010026773A1
• Time in Patent Office: 592 Days
• Field of Search: 436/161, 422/70, 422/99, 210/635, 210/638, 210/656, 210/659, 210/662, 210/663, 210/198.2, 204/450, 204/520, 204/536, 204/542
• US Class Current: 422/70
• CPC Class Codes: G01N 2030/965 suppressor columns
• CPC Class Codes: G01N 30/96 using ion-exchange G01N30/02, G01N30/90 take precedence

Abstract

An electrolyitic suppressor including (a) a suppressor bed of ion exchange resin, (b) an electrode chamber adjacent the suppressor, (c) a first electrode in the electrode chamber, (d) a barrier separating the suppressor bed from the first electrode chamber preventing significant liquid flow but permitting transport of ions only of the same charge as the suppressor bed resin, (e) a second electrode in electrical communication with the resin bed, and (f) a recycle conduit between the suppressor outlet port and said electrode chamber. The second electrode may be in contact with the ion exchange resin in the suppressor or located in second electrode chamber. For anion analysis, the method of using the apparatus includes: (a) flowing an aqueous liquid sample stream containing anions to be detected and cation hydroxide through the separator bed, (b) flowing the aqueous effluent from the separator bed through the flow-through suppressor, (c) flowing the effluent liquid from the suppressor past a detector, (d) recycling said liquid effluent from the detector through a cathode chamber proximate to the suppressor bed and separated by the first barrier, and (e) applying an electrical potential between the cathode and the anode. Water is electrolyzed at the anode to cause cations on the cation exchange resin to electromigrate toward the barrier and to be transported across the barrier toward the cathode while water in the cathode chamber is electrolyzed to generate hydroxide ions which combine with the transported cations to form cation hydroxide in the cathode chamber.

Claims

1. A suppressor for ion chromatography comprising:

(a) a flow-through suppressor adapted for continuous suppression and comprising an ion exchange resin bed having exchangeable ions of one charge, positive or negative, serving as a source of suppressing ions, said resin bed having an inlet section and an adjacent outlet section, said suppressor defining a liquid sample stream flow path between said resin bed inlet and outlet sections,

(b) at least one electrode chamber adjacent to said resin bed inlet section but not adjacent said resin bed outlet section,

(c) a first electrode disposed in said one electrode chamber in electrical communication with but not in direct contact with said flow path, and

(d) a second electrode disposed in or adjacent to said suppressor resin bed outlet section in electrical communication with said resin bed but not in or adjacent to said suppressor bed inlet section.

4. The suppressor of claims 1, 2, or 3 in combination with a detector in fluid communication with said resin bed outlet section.

5. The suppressor of claim 4 further comprising:

(e) a flow-through separator bed of ion exchange resin having exchangeable ions of opposite charge to the exchangeable ions of said suppressor resin bed, said separator bed outlet section being in fluid communication with said suppressor bed inlet section.

6. The suppressor of claims 1 or 2 further comprising:

(e) at least one barrier between said suppressor resin bed inlet section and said one electrode, said barrier permitting transport of ions only of the same charge as said suppressor resin bed exchangeable ions, said first electrode being in electrical communication with said first barrier.

7. The suppressor of claims 1 or 2 further comprising:

(e) at least one barrier between said resin bed and said one electrode adapted to separate hydrogen or oxygen gases created by the electrolysis of water near said first electrode from liquid eluent flowing in said suppressor resin bed flow path.

12. The suppressor of claims 1, 2 or 3 further comprising:

(e) a second electrode chamber adjacent to said suppressor bed outlet section, said second electrode being disposed in said second electrode chamber.

13. The suppressor of claim 12 further comprising:

(f) a second barrier between said suppressor bed and said second electrode, said barrier permitting transport of ions only of the same charge as said suppressor bed resin exchangeable ions.

14. The suppressor of claim 13 in which said second barrier also prevents significant liquid flow from said suppressor resin bed to said one electrode.

15. The suppressor of claim 12 further comprising:

(f) a second barrier between said resin bed and said second electrode separating hydrogen or oxygen gases created by the electrolysis of water near said second electrode from liquid eluent flow in said suppressor resin bed flow.

17. The suppressor of claim 15 in which said second barrier separates hydrogen or oxygen gases created by the electrolysis of water near said second electrode from liquid eluent flow in said suppressor resin bed flow path.

18. The suppressor of claims 1, 2 or 3 in which said suppressor bed ion exchange resin is a cation exchange resin, said first electrode is a cathode, and said second electrode is an anode.

19. The suppressor of claims 1, 2 or 3 in which said suppressor bed ion exchange resin is an anion exchange resin, said first electrode is an anode, and said second electrode is a cathode.

2. A suppressor for ion chromatography comprising:

(a) a flow-through suppressor adapted for continuous suppression and comprising an ion exchange resin bed having exchangeable ions of one charge, positive or negative, serving as a source of suppression ions, said resin bed having an inlet section and an adjacent outlet section, said suppressor defining a liquid sample stream flow path between said resin bed inlet and outlet sections,

(b) at least one electrode chamber adjacent to said resin bed inlet section but not adjacent said resin bed outlet section,

(c) a first electrode disposed in said one electrode chamber in electrical communication with but not in direct contact with said resin bed inlet-section, and

(d) a second electrode disposed in or adjacent to said suppressor resin bed outlet section in electrical communication with said resin bed but not in or adjacent to said suppressor bed inlet section.

3. A suppressor for ion chromatography comprising:

(a) a flow-through suppressor adapted for continuous suppression and comprising an ion exchange resin bed having exchangeable ions of one charge, positive or negative, serving as a source of suppression ions, said resin bed having an inlet section and an adjacent outlet section, said suppressor defining a liquid sample stream flow path between said resin bed inlet and outlet sections,

(b) at least one electrode chamber adjacent to said resin bed inlet section but not adjacent said resin bed outlet section,

(c) a first electrode disposed in said one electrode chamber in electrical communication with said resin bed inlet section,

(d) at least one barrier between said suppressor resin bed inlet section and said first electrode, said barrier permitting transport of ions only of the same charge as said suppressor resin bed exchangeable ions, said first electrode being in electrical communication with said first barrier, and

(e) a second electrode disposed in or adjacent to said suppressor resin bed outlet section in electrical communication therewith but not in or adjacent to said suppressor bed inlet section.

8. The suppressor of claim 3 in which said one barrier separates hydrogen or oxygen gases created by the electrolysis of water near said first electrode from liquid eluent flow in said suppressor resin bed flow path.

9. The suppressor of claim 3 in which said one barrier also prevents significant liquid flow between said suppressor resin bed and said one electrode.

10. The suppressor of claim 9 further comprising:

(g) at least one inlet port for said one electrode chamber, and

(h) a recycle conduit providing fluid communication in a path between said suppressor outlet section and said one electrode chamber inlet port.

11. The suppressor of claim 10 further comprising a detector disposed in the path of said recycle conduit to detect sample flowing through said recycle conduit.

16. The suppressor of claim 10 in which said recycle conduit also provides fluid communication with said second electrode chamber so that fluid in said recycle conduit flows sequentially from said suppressor outlet section through said second electrode chamber and then to said first electrode chamber.