Electrochemical detection cell for liquid chromatography system

• US 8,342,007 B2
• Filed: 02/10/2010
• Issued: 01/01/2013
• Est. Priority Date: 02/10/2010
• Status: Active Grant

• Current Assignee: Dionex Corporation (Thermo Fisher Scientific Incorporated)
• Original Assignee: Dionex Corporation (Thermo Fisher Scientific Incorporated)
• Inventors: Cheng, Jun, Jandik, Petr, Pohl, Christopher A.
• Primary Examiner(s): Rogers, David A.
• Assistant Examiner(s): Frank, Rodney T
• Application Number:
  US12/703,668
• Publication Number:
  US 20110192722A1
• Time in Patent Office: 1,056 Days
• Field of Search: 73/615.2, 422/68.1, 422/70, 210/656, 961/01
• US Class Current: 73/61.52
• CPC Class Codes: G01N 27/30 Electrodes, e.g. test electrodes; Half-cells G01N27/414 takes precedence
• CPC Class Codes: G01N 27/301 Reference electrodes
• CPC Class Codes: G01N 27/4166 measuring a particular property of an electrolyte
• CPC Class Codes: G01N 30/64 Electrical detectors

Abstract

A detection cell for a chromatography system includes a cell body having an inlet, an outlet, and a counter electrode, a working electrode, a sample flow passageway extending between the inlet and the outlet and in fluid contact with the counter and working electrodes, and a palladium/noble metal reference electrode system. A method of using the detection cell is also described.

Claims

1. A detection cell for a chromatography system, the detection cell comprising:

a cell body including a counter electrode;

a working electrode block including a working electrode;

a gasket separating the working electrode block from the cell body, the gasket defining a sample flow passageway extending between an inlet and an outlet of the detection cell and in fluid contact with the cell body and the working electrode; and

a reference electrode system in fluidic contact with the outlet and including an auxiliary electrode operably connected to a positive pole of a power supply and a palladium/hydrogen (PdH) reference electrode operably connected to a negative pole of the power supply.

2. A detection cell according to claim 1, wherein the detection cell is a three-electrode detection system.

3. A detection cell according to claim 1, wherein the cell body is formed of a conductive material.

4. A detection cell according to claim 1, wherein the cell body is formed of a corrosion resistant metal or a conductive polymer.

5. A detection cell according to claim 4, wherein the cell body is formed of a material selected from the group consisting of titanium, corrosion resistant alloy, stainless steel, carbon-loaded polyetherether ketone (PEEK), polythiophene, polyindole, and polynaphtalene.

6. A detection cell according to claim 1, wherein the reference electrode system includes a reference electrode of the first kind.

7. A detection cell according to claim 1, wherein the palladium/hydrogen (PdH) reference electrode and the auxiliary electrode are in electrical contact with the fluid sample passageway, and wherein the auxiliary electrode includes a platinum electrode.

8. A detection cell according to claim 7, wherein the palladium/hydrogen (PdH) reference electrode includes a wire extending into a reference electrode bore of the cell body.

9. A detection cell according to claim 1, wherein the a cell body includes an electrode cavity fluidly connected to the inlet and the outlet thereby forming a portion of the fluid sample passageway.

10. A detection cell according to claim 9, wherein at least one of the PdH reference electrode and the auxiliary electrode is a wire.

11. A chromatography system comprising the detection cell according to claim 9.

12. A chromatography system comprising the detection cell according to claim 1.

13. A chromatography system comprising a plurality of detection cells according to claim 1, wherein the detection cells are arranged in series.

14. A detection cell for a chromatography system, the detection cell comprising:

a cell body;

a working electrode block including a working electrode;

a sample channel extending between an inlet and an outlet of the detection cell and in fluid contact with the cell body and the working electrode;

a counter electrode in fluid contact with the sample channel; and

a reference electrode system in fluidic contact with the outlet and including an auxiliary electrode operably connected to a positive pole of a power supply and a palladium/hydrogen (PdH) reference electrode operably connected to a negative pole of the power supply.

15. A detection cell according to claim 14, wherein the cell body is formed of a conductive material.

16. A detection cell according to claim 14, wherein the palladium/hydrogen (PdH) reference electrode and the auxiliary electrode are in electrical contact with the sample channel, and in which the auxiliary electrode includes a platinum electrode.

17. A detection cell according to claim 14, wherein the palladium/hydrogen (PdH) reference electrode includes a wire extending into a reference electrode bore of the cell body.

18. A detection cell according to claim 14, wherein the reference electrode system operates at a potential less than approximately 3V subject to variations in voltage of less than approximately 10 mV.

19. A detection cell according to claim 14, wherein the channel has a volume of approximately 1 pL to 1 μ

L.