Randomly segmented thermoplastic polyurethanes as matrix for electrochemical analysis of Ca.sup.++ ions

• US 5,863,972 A
• Filed: 07/25/1997
• Issued: 01/26/1999
• Est. Priority Date: 11/14/1994
• Status: Expired due to Term

• Current Assignee: Siemens Healthcare Diagnostics Incorporated (Siemens AG)
• Original Assignee: Chiron Corporation (Bayer AG)
• Inventors: Beckelmann, Dirk, Berger, Joseph
• Primary Examiner(s): NILAND, PATRICK DENNIS
• Application Number:
  US08/836,370
• Time in Patent Office: 550 Days
• Field of Search: 524/186, 524/588, 524/589, 524/590, 128/635, 128/639, 128/642, 204/520, 204/400, 204/413, 204/415, 204/418, 422/82.03, 429/209, 429/250, 436/74
• US Class Current: 524/186
• CPC Class Codes: C08G 18/61 Polysiloxanes
• 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

Abstract

Composition, comprising in homogeneous distribution A) at least one salt containing a lipophilic anion, B) a plasticiser-free thermoplastic randomly segmented polyurethane which is soluble in organic solvents, a polyurea or a polyurethane urea, which components are formed from a) 5-45% by weight of an aromatic, cycloaliphatic or linear aliphatic dilsocyanate, b) 0-20% by weight of a linear or branched C2-C12alkylenediol or C2-C12alkylenediamine, c) 0-75% by weight of a polytetrahydrofuran or aminopropyl-terminated polytetrahydrofuran, d) 0-10% by weight of a polyethylene glycol or aminopropyl-terminated polyethylene glycol, e) 0-75% by weight of a polypropylene glycol or aminopropyl-terminated polypropylene glycol, which composition contains f) 15-95% by weight of a hydroxy-, hydroxypropyl- or aminopropyl-terminated polydimethylsiloxane, the percentages relating to the amount of polymer, and the sum of components a) to f) being 100, and C) a nonionic ionophore which forms a complex with Ca++ ions. The invention also relates to an electrode for calcium analysis, containing said composition in the form of a membrane, to a process for the electrochemical analysis of Ca++ ions in solution as well as to the use of this composition for the electrochemical analysis of Ca++ ions.

Claims

1. A composition, comprising in homogeneous distribution

A) at least one salt containing a lipophilic anion,

B) a plasticiser-free thermoplastic randomly segmented polyurethane which is soluble in organic solvents, a polyurea or a polyurethane urea, which components are formed from

a) 5-45% by weight of an aromatic, cycloaliphatic or linear aliphatic diisocyanate,

b) 0-20% by weight of a linear or branched C₂ -C₁₂ alkylenediol or C₂ -C₁₂ alkylenediamine,

c) 0-75% by weight of a polytetrahydrofuran or aminopropyl-terminated polytetrahydrofuran,

d) 0-10% by weight of a polyethylene glycol or aminopropyl-terminated polyethylene glycol,

e) 0-75% by weight of a polypropylene glycol or aminopropyl-terminated polypropylene glycol, which composition contains

f) 15-95% by weight of a hydroxy-, hydroxypropyl- or aminopropyl-terminated polydimethylsiloxane, the percentages relating to the amount of polymer, and the sum of components a) to f) being 100, and

C) a nonionic ionophore which forms a complex with Ca⁺⁺ ions.

2. A composition according to claim 1, wherein the aminopropyl-terminated polydimethylsiloxane has a molecular weight of 900 to 4500 dalton.

3. A composition according to claim 1, wherein the alkylenediamine is ethylenediamine, 1,4-diaminobutane or 1,6-diaminohexane.

4. A composition according to claim 1, wherein the aminopropyl-terminated polytetrahydrofuran has a molecular weight of 1000 to 4500 dalton.

5. A composition according to claim 1, wherein the aminopropyl-terminated polyethylene glycol has a molecular weight of 600 to 2000 dalton.

6. A composition according to claim 1, wherein the aminopropyl-terminated polypropylene glycol has a molecular weight of 1000 to 4000 dalton.

7. A composition according to claim 1, comprising in homogeneous distribution

A) at least one salt containing a lipophilic anion,

B) a plasticiser-free thermoplastic randomly segmented polyurethane which is soluble in organic solvents, a polyurea or a polyurethane urea, which components are formed from

a) 5-45% by weight of an aromatic, cycloaliphatic or linear aliphatic diisocyanate,

b) 0-20% by weight of a linear or branched C₂ -C₁₂ alkylenediol,

c) 0-75% by weight of a polytetrahydrofuran,

d) 0-10% by weight of a polyethylene glycol,

e) 0-75% by weight of a polypropylene glycol, which composition contains

f) 15-95% by weight of a hydroxy-, hydroxypropyl-terminated polydimethylsiloxane, the percentages relating to the amount of polymer, and the sum of components a) to f) being M 100, and

C) a nonionic ionophore which forms a complex with Ca⁺⁺ ions.

8. A composition according to claim 1, wherein the nonionic ionophore is an open-chain carbon chain containing several oxygen atoms.

9. A composition according to claim 8, wherein the ionophore is (R,R)-N,N'"'"'-bis 11-ethoxycarbonylundecyl!-N,N'"'"',4,5-tetramethyl-3,6-dioxaoctanediamide, N,N-dicyclohexyl-N'"'"',N'"'"'dioctadecyl-3-oxapentanediamide or N,N,N'"'"',N'"'"'-tetracyclohexyl-3-oxapentanediamide.

10. A composition according to claim 1, comprising the ionophore in an amount of 0.01 to 10% by weight, based on the amount of polymer.

11. A composition according to claim 10, comprising the ionophore in an amount of 0.1 to 5% by weight, based on the amount of polymer.

12. A composition according to claim 1, wherein the salt containing a lipophilic anion is an alkali metal salt or ammonium salt, and the anion contains unsubstituted or substituted tetraphenylborate.

13. A composition according to claim 12, wherein the cations are Li⁺, Na⁺, K⁺, NH₄⁺ and ammonium cations of primary, secondary and tertiary amines as well as quatemary ammonium cations containing 1 to 60 carbon atoms.

14. A composition according to claim 12, wherein the borate anion is tetraphenylborate whose phenyl groups are unsubstituted or substituted by one or more than one C₁ -C₄ alkyl, C₁ -C₄ alkoxy, halogen or trifluoromethyl.

15. A composition according to claim 14, wherein the borate anion is sodium tetraphenylborate, sodium tetra(3,5-bistrifluoromethylphenyl)borate, potassium tetra(4-chlorophenyl)borate, tetrabutylammoniumtetraphenylborate and tetradodecylammonium(4-chlorophenyl)borate.

16. A composition according to claim 12, wherein the amount of salts containing lipophilic anions is from 0.01 to 10% by weight, based on the amount of polymer.

17. A composition according to claim 1, wherein the diisocyanate is bis 4-isocyanatophenyl!methane (4,4'"'"' MDI), 2,4-or 2,6-bis isocyanato!toluene (TDI), 1,6-bis isocyanato!hexane (HDI), 5-isocyanato-3-(isocyanatomethyl)-1,1,3-trimethylcyclohexane (IPDI) or bis 4-isocyanatocyclohexyl!methane (MDI), or a mixture of these diisocyanates.

18. A composition according to claim 7, wherein the hydroxy- or hydroxypropyl-terminated polydimethylsiloxane has a molecular weight of 900 to 4500 dalton.

19. A composition according to claim 7, wherein the alkylenediol is ethylene glycol, 1,4-butanediol or 1,6-hexanediol.

20. A composition according to claim 7, wherein the polytetrahydrofuran has a molecular weight of 1000 to 4500 dalton.

21. A composition according to claim 7, wherein the polyethylene glycol has a molecular weight of 600 to 2000 dalton.

22. A composition according to claim 7, wherein the polypropylene glycol has a molecular weight of 1000 to 4000 dalton.

23. A composition according to claim 7, containing 4,4'"'"'-methylenediphenyidiisocyanate in an amount of 15-30% by weight, hydroxypropyl-terminated polydimethylsiloxane in an amount of 25-35% by weight, polytetrahydrofuran in an amount of 35-45% by weight and butanediol in an amount of 1-7% by weight, each based on the amount of the polymer, the sum of the percentages of the individual components being 100.

24. A composition according to claim 7, containing 4,4'"'"'-methylenediphenyidiisocyanate in an amount of 8-28% by weight, hydroxypropyl-terminated polydimethylsiloxane in an amount of 70-90% and butanediol in an amount of 0.1-5% by weight, each based on the amount of polymer, the sum of the percentages of the individual components being 100.

25. A composition according to claim 1, wherein the thermoplastic randomly segmented polyurethane, polyurea or polyurethane urea has a molecular weight of 10,000 to 250,000.

26. A composition according to claim 25, wherein the thermoplastic randomly segmented polyurethane, polyurea or polyurethane urea has a molecular weight of 10,000 to 100,000.

27. A composition according to claim 25, wherein the thermoplastic randomly segmented polyurethane, polyurea or polyurethane urea has a molecular weight of 10,000 to 30,000.

28. A composition according to claim 1, wherein the thermoplastic randomly segmented polyurethane, polyurea or polyurethane urea has a glass transition temperature from -125°

C. to -40°

C.

29. A composition according to claim 1, which is in the form of a membrane.

30. A composition according to claim 29, which is in the form of a self-supporting membrane.

31. A composition according to claim 29, wherein the membrane has a thickness of 50 μ

m to 500 μ

m.

32. An electrode for the analysis of Ca⁺⁺ ions, consisting of an outer assembly containing a) an aqueous CaCl₂ solution and an inner reference electrode, or b) a metal wire, the novel composition of claim 1 being applied a) in the form of a membrane or b) as a coating around the metal wire.

33. An electrode for the analysis of Ca⁺⁺ ions according to claim 32, wherein the aqueous CaCl₂ solution has a concentration of 0.001 to 0.5 molar.

34. A process for the analysis of Ca⁺⁺ ions in solution, which comprises

a) placing the novel composition of claim 1 in the form of a membrane into an electrode or using a metallic wire coated with the composition of claim 1 as electrode,

b) immersing the electrode with the membrane or polymer film in a measuring solution and measuring the electrical voltage difference against a standard electrode.

35. The composition according to claim 1 for use in the electrochemical analysis of Ca⁺⁺ ions in solutions.