Polymeric compositions for ion-selective electrodes

• US 6,432,296 B1
• Filed: 08/30/2000
• Issued: 08/13/2002
• Est. Priority Date: 09/24/1999
• Status: Expired due to Term

• Current Assignee: Andrew M. Kirsch, Daniel S. Daniel, James E. Love Jr, Richard C. Sutton, Richard L. Detwiler
• Original Assignee: Andrew M. Kirsch, Daniel S. Daniel, James E. Love Jr, Richard C. Sutton, Richard L. Detwiler
• Inventors: Daniel, Daniel S., Love, James E. Jr., Detwiler, Richard L., Sutton, Richard C., Kirsch, Andrew M.
• Primary Examiner(s): Warden, Sr., Robert J.
• Assistant Examiner(s): Olsen, Kaj K.
• Application Number:
  US09/651,048
• Time in Patent Office: 713 Days
• Field of Search: 204/414, 204/416, 204/418, 204/421, 204/435, 204/415, 205/778.5, 205/781.5, 205/787.5, 205/789, 205/789.5, 205/793, 205/779
• US Class Current: 205/789
• CPC Class Codes: G01N 27/3335 the membrane containing at least one organic component G01N27/3271 takes precedence; aspects concerning the enzyme reagent in enzyme electrodes C12Q1/001
• 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

Improved dry-operative ion-selective electrodes and their use are described. The dry-operative ion-selective electrodes include an internal reference electrode comprising a water-soluble salt dispersed in a polymer binder consisting essentially of a monomer having at least one carboxyl group and a hydrophobic monomer. The polymer provides reduced brittleness, good interlayer adhesion and high salt tolerance.

Claims

1. A dry-operative ion-selective electrode comprising:

a) an internal reference electrode comprising a water-soluble salt dispersed in a polymer consisting essentially of 60 to 99 weight percent of a monomer having at least one carboxyl group or salt thereof and 1 to 40 weight percent of a hydrophobic monomer; and

b) a hydrophobic zone in contact with the internal reference electrode, said hydrophobic zone having distributed therein a carrier selective for the ion.

2. The dry-operative ion-selective electrode of claim 1 further comprising a support, wherein the internal reference electrode is disposed between the support and the hydrophobic zone.

3. The dry-operative ion-selective electrode of claim 1 wherein the polymer consists essentially of 70 to 95 weight percent of a monomer having at least one carboxyl group or salt thereof and 5 to 30 weight percent of a hydrophobic monomer.

4. A dry-operative ion-selective electrode comprising:

a) an internal reference electrode comprising a water-soluble salt dispersed in a polymer consisting essentially of

i) 60 to 99 weight percent of a monomer of formula

 

wherein R₁ is H or —

COOM;

R₂ is H, Cl or —

COOM;

R₃ is —

COOM, —

CH₂CH₂COOM, —

CHCONHC(CH₃)₂CH₂COOM, or

 

M is H, alkali metal

 

wherein R₄, Rs, R₆, R₇ are independently H, methyl, or ethyl, and

ii) 1 to 40 weight percent of a monomer of formula

 

wherein R₈ is H or methyl;

R₉ is methoxy, ethoxy, propoxy, butoxy, hexoxy or —

NHCH₃; and

b) a hydrophobic zone in contact with the internal reference electrode, said hydrophobic zone having distributed therein a carrier selective for the ion.

5. The dry-operative ion-selective electrode of claim 4 further comprising a support, wherein the internal reference electrode is disposed between the support and the hydrophobic zone.

6. The dry-operative ion-selective electrode of claim 4 wherein the monomer in (i) is 70 to 95 weight percent and the monomer in (ii) is 5 to 30 weight percent.

7. The dry-operative ion-selective electrode of claim 4 wherein the ion-carrier is selective for cations.

8. The dry-operative ion-selective electrode of claim 4 wherein the ion-carrier is selective for anions.

9. The dry-operative ion-selective electrode of claim 4 wherein the ion-carrier is selective for metal ions.

10. The dry-operative ion-selective electrode of claim 4 wherein the ion-carrier is selective for alakali metal ions or alkaline earth metal ions.

11. The dry-operative ion-selective electrode of claim 4 wherein the ion-carrier is selective for potassium ion, sodium ion, lithium ion, magnesium ion, calcium ion, ammonium ion, hydrogen ion, cesium ion, bromide ion, chloride ion, fluoride ion, iodide ion, carbonate ion, salycilate ion or nitrate ion.

12. The dry-operative ion-selective electrode of claim 4 wherein the polymer is poly(ethyl acrylic acid-co-acrylic acid) or a salt thereof.

13. The dry-operative ion-selective electrode of claim 12 wherein ethyl acrylic acid is 10 weight percent and acrylic acid is 90 weight percent.

14. The dry-operative ion-selective electrode of claim 4 wherein said ion carrier is selected from the group consisting of valinomycin, a cyclic polyether, biscyclic ethers, cryptands, hemispherands, calixarenes, cyclic amides, tetraphenyl borate, a tetralactone, a macrolide acetone, a cyclic polypeptide, a quarternary ammonium salt, monensin, and esters of monensin.

15. A dry-operative ion-selective electrode comprising:

a) an internal reference electrode comprising a metal, an insoluble metal salt, a water-soluble salt, said water-soluble salt being dispersed in a polymer consisting essentially of 60 to 99 weight percent of a monomer having at least one carboxyl group or salt thereof and 1 to 40 weight percent of a hydrophobic monomer; and

b) a hydrophobic zone in contact with the internal reference electrode, said hydrophobic zone having distributed therein a carrier selective for the ion.

16. The dry-operative ion-selective electrode of claim 15 further comprising a support, wherein the internal reference electrode is disposed between the support and the hydrophobic zone.

17. The dry-operative ion-selective electrode of claim 15 wherein the polymer consists essentially of 70 to 95 weight percent of a monomer having at least one carboxyl group or salt thereof and 5 to 30 weight percent of a hydrophobic monomer.

18. A dry-operative ion-selective electrode comprising:

a) an internal reference electrode comprising a metal, an insoluble metal salt, a water-soluble salt, said water-soluble salt being dispersed in a polymer consisting essentially of

i) 60 to 99 weight percent of a monomer of formula

 

wherein R₁ is H or —

COOM;

R₂ is H, Cl or —

COOM;

R₃ is —

COOM, —

CH₂CH₂COOM, —

CHCONHC (CH₃) ₂CH₂COOM, or

 

M is H, alkali metal

 

wherein R₄, R5, R6, R₇ are independently H, methyl, or ethyl, and

ii) 1 to 40 weight percent of a monomer of formula

wherein R₈ is H or methyl;

R₉ is methoxy, ethoxy, propoxy, butoxy, hexoxy or NHCH₃; and

b) a hydrophobic zone in contact with the internal reference electrode, said hydrophobic zone having distributed therein a carrier selective for the ion.

19. The dry-operative ion-selective electrode of claim 18 further comprising a support, wherein the internal reference electrode is disposed between the support and the hydrophobic zone.

20. The dry-operative ion-selective electrode of claim 18 wherein the monomer in (i) is 70 to 95 weight percent and the monomer in (ii) is 5 to 30 weight percent.

21. The dry-operative ion-selective electrode of claim 18 wherein the ion-carrier is selective for cations.

22. The dry-operative ion-selective electrode of claim 18 wherein the ion-carrier is selective for anions.

23. The dry-operative ion-selective electrode of claim 18 wherein the ion-carrier is selective for metal ions.

24. The dry-operative ion-selective electrode of claim 18 wherein the ion-carrier is selective for alakali metal ions or alkaline earth metal ions.

25. The dry-operative ion-selective electrode of claim 18 wherein the ion-carrier is selective for potassium ion, sodium ion, lithium ion, magnesium ion, calcium ion, ammonium ion, hydrogen ion, cesium ion, bromide ion, chloride ion, fluoride ion, iodide ion, carbonate ion, salycilate ion or nitrate ion.

26. The dry-operative ion-selective electrode of claim 18 wherein the polymer is poly(ethyl acrylic acid-co-acrylic acid) or a salt thereof.

27. The dry-operative ion-selective electrode of claim 26 wherein ethyl acrylic acid is 10 weight percent and acrylic acid is 90 weight percent.

28. The dry-operative ion-selective electrode of claim 18 wherein said ion carrier is selected from the group consisting of valinomycin, a cyclic polyether, biscyclic ethers, cryptands, hemispherands, calixarenes, cyclic amides, tetraphenyl borate, a tetralactone, a macrolide acetone, a cyclic polypeptide, a quarternary ammonium salt, monensin, and esters of monensin.

29. A method for determining the presence or amount of an ion in a liquid comprising:

A) contacting a dry-operative ion-selective first electrode with a sample of the liquid wherein the dry-operative first electrode comprises

a) an internal reference electrode comprising a water-soluble salt dispersed in a polymer consisting essentially of 60 to 99 weight percent of a monomer having at least one carboxyl group or salt thereof and 1 to 40 weight percent of a hydrophobic monomer; and

b) a hydrophobic zone in contact with the internal reference electrode, said hydrophobic zone having distributed therein a carrier selective for the ion,

B) contacting a second electrode with a solution comprising a known or constant amount of an ion to which said second electrode is selective and wherein said dry-operative first electrode and said second electrode are in electrochemical contact or are capable of being in electrochemical contact;

or

C) contacting the dry-operative ion-selective first electrode and the second electrode with the same sample of the liquid, wherein the sample comprises a known or constant amount of an ion to which said second electrode is selective; and

D) measuring the potential difference between the dry-operative first electrode and the second electrode as a determination of the presence or amount of the ion in the liquid sample.

30. The method of claim 29 wherein the dry-operative first electrode comprises a support and the internal reference electrode is disposed between the support and the hydrophobic zone, and wherein said first electrode and said second electrode in B are selective for the same ion.

31. The method of claim 29 wherein the polymer consists essentially of 70 to 95 weight percent of a monomer having at least one carboxyl group or salt thereof and 5 to 30 weight percent of a hydrophobic monomer.

32. A method for determining the presence or amount of an ion in a liquid comprising:

A) contacting a dry-operative ion-selective first electrode with a sample of the liquid wherein the dry-operative first electrode comprises

a) an internal reference electrode comprising a water-soluble salt dispersed in a polymer consisting essentially of

i) 60 to 99 weight percent of a monomer of formula

 

wherein R₁ is H or —

COOM;

R₂ is H, Cl or —

COOM;

R₃ is —

COOM, —

CH₂CH₂COOM, —

CHCONHC (CH₃) ₂CH₂COOM, or

 

M is H, alkali metal

 

wherein R₄, R5, R₆, R₇ are independently H, methyl, or ethyl, and

ii) 1 to 40 weight percent of a monomer of formula

 

wherein R₈ is H or methyl;

R₉ is methoxy, ethoxy, propoxy, butoxy, hexoxy or —

NHCH₃,

b) a hydrophobic zone, in contact with the internal reference electrode, said hydrophobic zone having distributed therein a carrier selective for the ion;

B) contacting a second electrode with a solution comprising a known or constant amount of an ion to which said second electrode is selective and wherein said dry-operative first electrode and said second electrode are in electrochemical

C) contacting the dry-operative ion-selective first electrode and the second electrode with the same sample of the liquid, wherein the sample comprises a known or constant amount of an ion to which said second electrode is selective; and

D) measuring the potential difference between the dry-operative first electrode and the second electrode as a determination of the presence or amount of the ion in the liquid sample.

33. The method of claim 32 wherein the dry-operative first electrode comprises a support and the internal reference electrode is disposed between the support and the hydrophobic zone, and wherein said first electrode and said second electrode in B are selective for the same ion.

34. The method of claim 32 wherein the monomer in (i) is 70 to 95 weight percent and the monomer in (ii) is 5 to 30 weight percent.

35. The method of claim 32 wherein the ion-carrier is selective for cations.

36. The method of claim 32 wherein the ion-carrier is selective for anions.

37. The method of claim 32 wherein the ion-carrier is selective for metal ions.

38. The method of claim 32 wherein the ion-carrier is selective for alakali metal ions or alkaline earth metal ions.

39. The method of claim 32 wherein the ion-carrier is selective for potassium ion, sodium ion, lithium ion, magnesium ion, calcium ion, ammonium ion, hydrogen ion, cesium ion, bromide ion, chloride ion, fluoride ion, iodide ion, carbonate ion, salycilate ion or nitrate ion.

40. The method of claim 32 wherein the polymer is poly(ethyl acrylic acid-co-acrylic acid) or a salt thereof.

41. The method of claim 40 wherein ethyl acrylic acid is 10 weight percent and acrylic acid is 90 weight percent.

42. The method of claim 32 wherein the second electrode is a dry-operative electrode.

43. The method of claim 42 wherein the dry-operative second electrode comprises

a) an internal reference electrode comprising a water-soluble salt dispersed in a polymer consisting essentially of

i) 60 to 99 weight percent of a monomer of formula

  wherein R₁ is H or —

COOM;

R₂ is H, Cl or —

COOM;

R₃ is —

COOM, —

CH₂CH₂COOM, —

CHCONHC(CH₃)₂CH₂COOM, or

 

M is H, alkali metal

 

wherein R₄, R₅, R₆, R₇ are independently H, methyl, or ethyl, and

ii) 1 to 40 weight percent of a monomer of formula

 

wherein R₈ is H or methyl;

R₉ is methoxy, ethoxy, propoxy, butoxy, hexoxy or —

NHCH₃; and

b) a hydrophobic zone in contact with the internal reference electrode, said hydrophobic zone having distributed therein a carrier selective for the ion.

44. The method of claim 43 wherein the dry-operative first electrode and the dry-operative second electrode have the same structure and composition.

45. The method of claim 32 wherein said ion is carrier is selected from the group consisting of valinomycin, a cyclic polyether, biscyclic ethers, cryptands, hemispherands, calixarenes, cyclic amides, tetraphenyl borate, a tetralactone, a macrolide acetone, a cyclic polypeptide, a quarternary ammonium salt, monensin, and esters of monensin.

46. A method for determining the presence or amount of an ion in a liquid comprising:

A) contacting a dry-operative ion-selective first electrode with a sample of the liquid, wherein said first electrode comprises

a) an internal reference electrode comprising a metal, an insoluble metal salt, a water-soluble salt, said water-soluble salt being dispersed in a polymer consisting essentially of 60 to 99 having at least one carboxyl group or salt thereof and 1 to 40 weight percent of a hydrophobic monomer; and

,

b) a hydrophobic zone in contact with the internal reference electrode, said hydrophobic zone having distributed therein a carrier selective for the ion;

B) contacting a second electrode with a solution comprising a known or constant amount of an ion to which said second electrode is selective and wherein said dry-operative first electrode and said second electrode are in electrochemical contact or are capable of being in electrochemical contact;

or

C) contacting the dry-operative ion-selective first electrode and the second electrode with the same sample of the liquid, wherein the sample comprises a known or constant amount of an ion to which said second electrode is selective; and

D) measuring the potential difference between the dry-operative first electrode and the second electrode as a determination of the presence or amount of the ion in the liquid sample.

47. The method of claim 46 wherein the dry-operative first electrode comprises a support and the internal reference electrode is disposed between the support and the hydrophobic zone, and wherein said first electrode and said second electrode in B are selective for the same ion.

48. The method of claim 46 wherein the polymer consists essentially of 70 to 95 weight percent of a monomer having at least one carboxyl group or salt thereof and 5 to 30 weight percent of a hydrophobic monomer.

49. A method for determining the presence or amount of an ion in a liquid comprising:

A) contacting a dry-operative ion-selective first electrode with a sample of the liquid, wherein said first electrode comprises

a) an internal reference electrode comprising a metal, an insoluble metal salt, a water-soluble salt, said water-soluble salt being dispersed in a polymer consisting essentially of

i) 60 to 99 weight percent of a monomer of formula

 

wherein R₁ is H or —

COOM;

R₂ is H, Cl or —

COOM;

R₃ is —

COOM, —

CH₂CH₂COOM, —

CHCONHC(CH₃)₂CH₂COOM, or

 

M is H, alkali metal

 

wherein R₄, R₅, R6, R₇ are independently H, methyl, or ethyl, and

ii) 1 to 40 weight percent of a monomer of formula

 

wherein R₈ is H or methyl;

R₉ is methoxy, ethoxy, propoxy, butoxy, hexoxy or —

NHCH₃,

b) a hydrophobic zone in contact with the internal reference electrode, said hydrophobic zone having distributed therein a carrier selective for the ion;

B) contacting a second electrode with a solution comprising a known or constant amount of an ion to which said second electrode is selective and wherein said dry-operative first electrode and said second electrode are in electrochemical contact or are capable of being in electrochemical contact;

or

C) contacting the dry-operative ion-selective first electrode and the second electrode with the same sample of the liquid, wherein the sample comprises a known or constant amount of an ion to which said second electrode is selective; and

D) measuring the potential difference between the dry-operative first electrode and the second electrode as a determination of the presence or amount of the ion in the liquid sample.

50. The method of claim 49 wherein the dry-operative first electrode comprises a support and the internal reference electrode is disposed between the support and the hydrophobic zone, and wherein said first electrode and said second electrode in B are selective for the same ion.

51. The method of claim 49 wherein the monomer in (i) is 70 to 95 weight percent and the monomer in (ii) is 5 to 30 weight percent.

52. The method of claim 49 wherein the ion-carrier is selective for cations.

53. The method of claim 49 wherein the ion-carrier is selective for anions.

54. The method of claim 49 wherein the ion-carrier is selective for metal ions.

55. The method of claim 49 wherein the ion-carrier is selective for alakali metal ions or alkaline earth metal ions.

56. The method of claim 49 wherein the ion-carrier is selective for potassium ion, sodium ion, lithium ion, magnesium ion, calcium ion, ammonium ion, hydrogen ion, cesium ion, bromide ion, chloride ion, fluoride ion, iodide ion, carbonate ion, salycilate ion or nitrate ion.

57. The method of claim 49 wherein the polymer is poly(ethyl acrylic acid-co-acrylic acid) or salt thereof.

58. The method of claim 57 wherein ethyl acrylic acid is 10 weight percent and acrylic acid is 90 weight percent.

59. The method of claim 49 wherein the second electrode is a dry-operative electrode.

60. The method of claim 59 wherein the dry-operative second electrode comprises

a) an internal reference electrode comprising a water-soluble salt dispersed in a polymer consisting essentially of

i) 60 to 99 weight percent of a monomer of formula

  wherein R, is H or —

COOM;

R₂ is H, Cl or —

COOM;

R₃ is —

COOM, —

CH₂CH₂COOM, —

CHCONHC (CH₃) ₂CH₂COOM, or

 

M is H, alkali metal

 

wherein R₄, R₅, R₆, R₇ are independently H, methyl, or ethyl, and

ii) 1 to 40 weight percent of a monomer of formula

 

wherein R₈ is H or methyl;

R₉ is methoxy, ethoxy, propoxy, butoxy, hexoxy or —

NHCH₃; and

b) a hydrophobic zone in contact with the internal reference electrode, said hydrophobic zone having distributed therein a carrier selective for the ion.

61. The method of claim 60 wherein the dry-operative first electrode and the dry-operative second electrode have the same structure and composition.

62. The method of claim 49 wherein said ion carrier is selected from the group consisting of valinomycin, a cyclic polyether, biscyclic ethers, cryptands, hemispherands, calixarenes, cyclic amides, tetraphenyl borate, a tetralactone, a macrolide acetone, a cyclic polypeptide, a quarternary ammonium salt, monensin, and esters of monensin.