Electrochemical detection cell for liquid chromatography system

• US 8,925,374 B2
• Filed: 11/30/2012
• Issued: 01/06/2015
• 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): Williams, Hezron E
• Assistant Examiner(s): Frank, Rodney T
• Application Number:
  US13/689,885
• Publication Number:
  US 20130091936A1
• Time in Patent Office: 767 Days
• Field of Search: 73/615.2
• 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 working electrode;

a counter electrode;

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

a reference electrode system in fluidic contact with the outlet and including an auxiliary electrode 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, in which the auxiliary electrode is positioned downstream from the working electrode and the counter electrode.

2. The detection cell of claim 1 further comprising a gasket that defines the sample channel.

3. The detection cell of claim 1, in which the gasket is disposed in between the counter electrode and the working electrode.

4. The detection cell of claim 1, in which the sample channel has a volume of approximately 1 pL to 1 μ

L.

5. The detection cell of claim 1, in which the palladium/hydrogen (PdH) reference electrode and the auxiliary electrode are in electrical contact with the sample channel.

6. The detection cell of claim 1, in which the reference electrode system operates at a potential less than approximately 3 volts subject to variations in voltage of less than approximately 10 millivolts.

7. A chromatography system comprising:

a detection cell for a chromatography system, the detection cell comprising;

a working electrode;

a counter electrode;

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

a reference electrode system in fluidic contact with the outlet and including an auxiliary electrode 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; and

a separation column operably connected to the detection cell.

8. The chromatography system of claim 7 further comprising:

an electrolytic suppressor operably connected to the detection cell.

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

a working electrode;

a counter electrode;

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

a reference electrode system in fluidic contact with the outlet and including an auxiliary electrode 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, in which the working electrode comprises a material selected from the group consisting of gold and platinum.

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

a working electrode;

a counter electrode;

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

a reference electrode system in fluidic contact with the outlet and including an auxiliary electrode 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, in which the auxiliary electrode comprises a material selected from the group consisting of platinum, glassy carbon, and graphite.