Combination ion-selective electrode with a replaceable sensing membrane

• US 6,398,931 B1
• Filed: 01/31/2000
• Issued: 06/04/2002
• Est. Priority Date: 01/31/2000
• Status: Expired due to Fees

• Current Assignee: Phoenix Electrode Company
• Original Assignee: Phoenix Electrode Company
• Inventors: Boyle, Peter F., Chu, Dung Van, Burchette, Raymond Gary
• Primary Examiner(s): Warden, Sr., Robert J.
• Assistant Examiner(s): Olsen, Kaj K.
• Application Number:
  US09/495,084
• Time in Patent Office: 855 Days
• Field of Search: 204/416, 204/417, 204/418, 204/419, 204/420, 204/435
• US Class Current: 204/416
• CPC Class Codes: G01N 27/333 Ion-selective electrodes or membranes glass electrodes G01N27/36
• CPC Class Codes: G01N 27/4035 Combination of a single ion-sensing electrode and a single reference electrode G01N27/406 and G01N27/413 take precedence

Abstract

An improved combination ion-selective electrode apparatus is provided that comprises an electrode body, a reference electrode, and an ion-sensing electrode. The reference electrode comprises a ion-permeable junction. A removable membrane cap contains a ion-selective membrane. The membrane cap can be removed from the ion-selective electrode apparatus without endangering the integrity of the reference electrode and is distinct from the ion-permeable junction. The membrane cap contains a removable ion-sensitive membrane that can be replaced if the ion-sensitive membrane fails to thereby place the combination ion-selective electrode apparatus back into service. Moreover, a single combination ion-selective electrode apparatus can be used to measure a variety of analyte ions by simple replacement of the membrane cartridge.

Claims

1. A combination ion-selective electrode comprising:

a removable cap holding an ion-selective membrane wherein a liquid junction is not formed between a reference electrolyte and a sample solution, and wherein said cap and ion-selective membrane may be removed without loss of said reference electrolyte from the combination ion-selective electrode.

2. The ion-selective electrode of claim 1 wherein said ion-selective membrane may be replaceably connected within said cap.

3. The ion-selective electrode of claim 2 wherein said ion-selective membrane is a crystal membrane.

4. The ion-selective electrode of claim 2 wherein said ion-selective membrane is an epoxy membrane.

5. The ion-selective electrode of claim 2 wherein said ion-selective membrane is a pressed pellet membrane.

6. The ion-selective electrode of claim 2 wherein said ion-selective membrane is a polymer membrane.

7. The ion-selective electrode of claim 1 wherein said ion-selective membrane is a crystal membrane.

8. The ion-selective electrode of claim 1 wherein said ion-selective membrane is an epoxy membrane.

9. The ion-selective electrode of claim 1 wherein said ion-selective membrane is a pressed pellet membrane.

10. The ion-selective electrode of claim 1 wherein said ion-selective membrane is a polymer membrane.

11. The ion-selective electrode of claim 1 wherein said cap is removably connected to an ion-permeable junction member.

12. The ion-selective electrode of claim 11 wherein said ion-permeable junction member is formed of ceramic.

13. A combination ion-selective electrode comprising:

an electrode body having a reference half-cell including a reference electrolyte;

an ion-permeable junction connected to said electrode body;

an ion-selective electrode disposed through said ion-permeable junction in a manner such that a liquid junction is not formed between said reference electrolyte and a sample solution; and

an ion-selective membrane removably connected to said ion-permeable junction without loss or contamination of said reference electrolyte, said ion-selective membrane in functional connection with said ion-selective electrode.

14. The ion-selective electrode of claim 13 wherein said ion-selective electrode is spring loaded for urging said electrode in functional connection with said ion-selective membrane.

15. The ion-selective electrode of claim 13 wherein said ion-selective electrode is functionally connected to said ion-selective membrane via a filling solution.

16. The ion-selective electrode of claim 13 wherein said ion-selective electrode is held by a cap removably connected to said ion-permeable junction.

17. The ion-selective electrode of claim 16 wherein said ion-selective electrode is replaceably connected to said cap.

18. The ion-selective electrode of claim 17 wherein said ion-selective electrode is spring loaded for functionally connecting to said ion-selective membrane.

19. The ion-selective electrode of claim 17 wherein said ion-selective electrode is functionally connected to said ion-selective membrane via a filling solution.

20. The ion-selective electrode of claim 16 wherein said ion-selective electrode is spring loaded for functionally connecting to said ion-selective membrane.

21. The ion-selective electrode of claim 16 wherein said ion-selective electrode is functionally connected to said ion-selective membrane via a filling solution.

22. A combination ion-selective electrode comprising:

an electrode body having a reference half-cell including a reference electrolyte;

an ion-permeable junction connected to said electrode body;

an ion-selective electrode disposed through said ion-permeable junction in a manner to prevent fluid from escaping from said electrode body and not form a liquid junction between said reference electrolyte and a sample solution; and

an ion-selective membrane removably connected to said ion-permeable junction without loss or contamination of said reference electrolyte, said ion-selective membrane in functional connection with said ion-selective electrode.

23. The ion-selective electrode of claim 22 wherein said ion-selective electrode is spring loaded for urging said electrode in functional connection with said ion-selective membrane.

24. The ion-selective electrode of claim 22 wherein said ion-selective electrode is functionally connected to said ion-selective membrane via a filling solution.

25. The ion-selective electrode of claim 22 wherein said ion-selective electrode is held by a cap removably connected to said ion-permeable junction.

26. The ion-selective electrode of claim 25 wherein said ion-selective electrode is replaceably connected to said cap.

27. The ion-selective electrode of claim 26 wherein said ion-selective electrode is spring loaded for functionally connecting to said ion-selective membrane.

28. The ion-selective electrode of claim 26 wherein said ion-selective electrode is functionally connected to said ion-selective membrane via a filling solution.

29. The ion-selective electrode of claim 25 wherein said ion-selective electrode is spring loaded for functionally connecting to said ion-selective membrane.

30. The ion-selective electrode of claim 25 wherein said ion-selective electrode is functionally connected to said ion-selective membrane via a filling solution.

31. A combination ion-selective electrode comprising:

an electrode body having a reference half-cell including a reference electrolyte;

an ion-permeable junction connected to said electrode body;

an ion-selective electrode disposed through said ion-permeable junction in a manner to prevent fluid from escaping from said electrode body and not form a liquid junction between said reference electrolyte and a sample solution; and

a cap holding a replaceable ion-selective membrane, said cap removably connected to said ion-permeable junction without loss or contamination of said reference electrolyte, said ion-selective membrane in functional connection with said ion-selective electrode.

32. The ion-selective electrode of claim 31 wherein said ion-selective electrode is spring loaded for urging said electrode in functional connection with said ion-selective membrane.

33. The ion-selective electrode of claim 31 wherein said ion-selective electrode is functionally connected to said ion-selective membrane via a filling solution.