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US4476005A
Expired / Lapsed
US
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Urease-immobilized urea electrode and process for preparing the same
Assignee: Hitachi Ltd
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Filing: 1983-09-30
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Granted: 1984-10-09
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Expires: 2003-09-30
Abstract
Abstract Urea electrode comprises a urease-immobilized membrane having added amino groups prepared by dipping an immobilized membrane in an aqueous solution of ethylenediamine or polylysine and an electrode for quantitative determination of ammonium ions. The electrode has a shorter measurement time with a larger electrode output.
Inventors
- 👤 Daizo Tokinaga
- 👤 Teruaki Kobayashi
- 👤 Akiko Katori
- 👤 Yoshiharu Karasawa
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 13:03
CPC Classifications
C; C12; C12Q; C12Q1/00; C12Q1/001; C12Q1/002; C12Q1/005; Y; Y10; Y10S; Y10S435/00; Y10S435/817
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
27 words
A urea electrode comprising a urease-immobilized membrane and an electrode for quantitative determination of ammonium ions, the urease-immobilized membrane having added amino groups in the membrane structure.
Claim 2
Dependent Claim
27 words
A urea electrode comprising a urease-immobilized membrane and an electrode for quantitative determination of ammonium ions, the urease-immobilized membrane having added amino groups in the membrane structure.
Claim 3
Dependent Claim
25 words
A urea electrode according to claim 1, wherein the urease-immobilized membrane has at least 10 18 amino groups per 1 cm 3 of membrane volume.
Claim 4
Dependent Claim
19 words
A urea electrode according to claim 1 or 2, wherein the urease-immobilized membrane is a membrane immobilized by glutaraldehyde.
Claim 5
Dependent Claim
40 words
A urea electrode according to claim 1, wherein the urease-immobilized membrane having added amino groups is a membrane prepared by dipping an urease-immobilized membrane in an aqueous solution of a compound having at least two amino groups in one molecule.
Claim 6
Dependent Claim
22 words
A urea electrode according to claim 4, wherein the compound is a compound having a molecular weight of not more than 3,000.
Claim 7
Dependent Claim
15 words
A urea electrode according to claim 5, wherein the compound is ethylenediamine, guanidine or polylysine.
Claim 8
Independent Claim
41 words
A method for preparing a urease-immobilized membrane having added amino groups in the membrane structure for a urea electrode, which comprises dipping a urease-immobilized membrane in an aqueous solution of a compound having at least two amino groups in one molecule.
Claim 9
Independent Claim
41 words
A method for preparing a urease-immobilized membrane having added amino groups in the membrane structure for a urea electrode, which comprises dipping a urease-immobilized membrane in an aqueous solution of a compound having at least two amino groups in one molecule.
Claim 10
Dependent Claim
21 words
A method according to claim 7, wherein the compound is a compound having a molecular weight of not more than 3,000.
Claim 11
Dependent Claim
13 words
A method according to claim 8, wherein the compound is ethylenediamine or polylysine.
References Cited (Backward Citations)
US3776819A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-10-09 | 1988-04-09 | 1988-10-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-10-09 | 1992-04-09 | 1992-10-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-10-09 | 1996-04-09 | 1996-10-09 | $7700.00 | Window Closed / Lapsed |