US4297173A
Expired / Lapsed
US
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Method for determining ammonia and sensor therefor
Assignee: Ajinomoto Co Inc
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Filing: 1980-05-22
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Granted: 1981-10-27
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Expires: 2000-05-22
Abstract
Abstract The concentration of ammonia in an aqueous liquid is determined by contacting a sample of the liquid with dissolved oxygen and with a microbial electrode comprising an oxygen-sensitive electrode, a porous membrane, and nitrifying bacteria confined or immobilised by the membrane which are in direct or close contact with the diaphragm of the electrode. The rate of oxygen consumption under otherwise uniform conditions is as precise a measure of concentration of ammonia as a conventional colorimetric method and distillation-titration method.
Inventors
- 👤 Motohiko Hikuma
- 👤 Tatsuru Kubo
- 👤 Takeo Yasuda
- 👤 Isao Karube
- 👤 Shuichi Suzuki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 16:59
CPC Classifications
C; C12; C12Q; C12Q1/00; C12Q1/02; C12Q1/04; C12Q1/12; C12Q1/001; Y; Y10; Y10S; Y10S435/00; Y10S435/817; Y10T; Y10T436/00; Y10T436/17; Y10T436/173845; Y10T436/175383
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
117 words
A method for determining ammonia concentration in an aqueous liquid which contains dissolved oxygen, which comprises: (a) Contacting a sample of said liquid with a microbial electrode comprising: an oxygen-sensitive electrode having a diaphragm, bacteria capable of oxidizing ammonium ion and thereby consuming oxygen in direct or close contact with the diaphragm of said oxygen sensitive electrode, said bacteria being confined or immobilized by a porous membrane permeable to ammonia and to oxygen and impermeable to microbial cells; and (b) electrochemically sensing the rate of consumption or their decrease in steady state concentration of said oxygen caused by said microorganisms, and thereby (c) detecting the concentration of ammonia from said rate or said decrease of the oxygen.
Claim 2
Independent Claim
117 words
A method for determining ammonia concentration in an aqueous liquid which contains dissolved oxygen, which comprises: (a) Contacting a sample of said liquid with a microbial electrode comprising: an oxygen-sensitive electrode having a diaphragm, bacteria capable of oxidizing ammonium ion and thereby consuming oxygen in direct or close contact with the diaphragm of said oxygen sensitive electrode, said bacteria being confined or immobilized by a porous membrane permeable to ammonia and to oxygen and impermeable to microbial cells; and (b) electrochemically sensing the rate of consumption or their decrease in steady state concentration of said oxygen caused by said microorganisms, and thereby (c) detecting the concentration of ammonia from said rate or said decrease of the oxygen.
Claim 3
Dependent Claim
37 words
A method as set forth in claim 1 wherein said membrane is selectively permeable to ammonia gas or to cations and said bacteria are held between the diaphragm of the electrode and said membrane covering the diaphragm.
Claim 4
Dependent Claim
19 words
A method as set forth in claim 1 wherein said sample solution is saturated with oxygen during the determination.
Claim 5
Dependent Claim
19 words
The method of claim 1 wherein said bacteria comprise those capable of oxidizing ammonia to form nitrous acid therefrom.
Claim 6
Dependent Claim
21 words
The method of claim 4 wherein said bacteria also comprise bacteria capable of oxidizing nitrous acid to form nitric acid therefrom.
Claim 7
Dependent Claim
20 words
The method of claim 5 wherein said bacteria are selected from the group consisting of Nitrobacter winogradski and Nitrocystis sarcinoides.
Claim 8
Dependent Claim
25 words
The method of claim 4 wherein said bacteria are selected from the group consisting of Nitrosomonas monocella, Nitrosococcus nitrosus, Nitrosopira briensis, Nitrososocystis javanensis, Nitrosogloea merismoides.
Claim 9
Dependent Claim
27 words
The method of claim 1 wherein said bacteria are selected from the group consisting of Nitrosomonas europaea ATCC 19718 and Nitrobacter agilis ATCC 14123 and mixtures thereof.
Claim 10
Dependent Claim
58 words
An ammonia-detecting electrode which comprises: an oxygen-sensitive electrode having a diaphragm; bacteria capable of oxidizing ammonium ion and thereby consuming oxygen in direct or close contact with the diaphragm of said oxygen sensitive electrode; said bacteria being confined or immobilized by a porous membrane permeable to ammonia or ammonium ions and to oxygen, and impermeable to microbial cells.
Claim 11
Dependent Claim
58 words
An ammonia-detecting electrode which comprises: an oxygen-sensitive electrode having a diaphragm; bacteria capable of oxidizing ammonium ion and thereby consuming oxygen in direct or close contact with the diaphragm of said oxygen sensitive electrode; said bacteria being confined or immobilized by a porous membrane permeable to ammonia or ammonium ions and to oxygen, and impermeable to microbial cells.
Claim 12
Dependent Claim
35 words
The electrode of claim 9 wherein said membrane is selectively permeable to ammonia gas or to ions thereof and said bacteria are held between the diaphragm of the electrode and said membrane covering the diaphragm.
Claim 13
Dependent Claim
19 words
The electrode of claim 9 wherein said bacteria comprise those capable of oxidizing ammonia to form nitrous acid therefrom.
Claim 14
Dependent Claim
25 words
The method of claim 11 wherein said bacteria are selected from the group consisting of Nitrosomonas monocella, Nitrosococcus nitrosus, Nitrosospira briensis, Nitrososocystis javanensis, Nitrosogloea merismoides.
Claim 15
Dependent Claim
21 words
The method of claim 9 wherein said bacteria also comprise bacteria capable of oxidizing nitrous acid to form nitric acid therefrom.
Claim 16
Dependent Claim
20 words
The electrode of claim 13 wherein said bacteria are selected from the group consisting of Nitrobacter winogradski and Nitrocystis sarcinoides.
Claim 17
Dependent Claim
24 words
The electrode of claim 9 wherein said bacteria are selected from the group consisting of Nitrosomonas europaea ATCC 19718 and Nitrobacter agilis ATCC 14123.
References Cited (Backward Citations)
US4216065A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-10-26 | 1985-04-27 | 1985-10-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-10-26 | 1989-04-27 | 1989-10-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-10-26 | 1993-04-27 | 1993-10-27 | $7700.00 | Window Closed / Lapsed |