Patent US5645709A successfully refreshed from Google Patents.
US5645709A
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Methods and apparatus for electrochemical measurements
Assignee: Van den Bergh Foods Co
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Filing: 1994-12-07
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Granted: 1997-07-08
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Expires: 2014-12-07
Abstract
Abstract A method for the electrochemical determination of the reducing sugars content of an aqueous solution in a thin layer electrochemical measuring device, preferably a capillary fill device, wherein an inner surface of the device is coated with a soluble redox mediator, the device including means for producing an alkaline environment within the device. In a preferred method the redox mediator comprises potassium ferricyanide providing ferricyanide ions in saturated solution and lithium hydroxide providing hydroxide ions in an excess amount of from 1 to 3 molar. The invention also provides a capillary fill device having a guard electrode between the reference and working electrodes.
Inventors
- 👤 Brian Jeffrey Birch
- 👤 Nicholas Andrew Morris
- 👤 Vincent Bonnafoux
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 19:12
CPC Classifications
G; G01; G01N; G01N27/00; G01N27/26; G01N27/28; G01N27/30; G01N27/327
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
84 words
A non-enzymic method of selectively determining the content of reducing sugars only in an aqueous solution, comprising forming a thin layer having a thickness of less than about 1 mm of a solution to be tested in an alkaline environment containing a soluble redox mediator and in the absence of enzymes catalyzing reactions of reducing sugars; determining electrochemically the amount of reduction product of the redox mediator; and determining from the amount of reduction product the content of reducing sugars in the aqueous solution.
Claim 2
Dependent Claim
84 words
A non-enzymic method of selectively determining the content of reducing sugars only in an aqueous solution, comprising forming a thin layer having a thickness of less than about 1 mm of a solution to be tested in an alkaline environment containing a soluble redox mediator and in the absence of enzymes catalyzing reactions of reducing sugars; determining electrochemically the amount of reduction product of the redox mediator; and determining from the amount of reduction product the content of reducing sugars in the aqueous solution.
Claim 3
Dependent Claim
12 words
A method according to claim 1, wherein the redox mediator comprises ferricyanide.
Claim 4
Dependent Claim
19 words
A method according to claim 1, wherein the mediator is present in an amount to form a saturated solution.
Claim 5
Dependent Claim
19 words
A method according to claim 1, wherein the thin layer has a thickness of less than about 0.5 mm.
Claim 6
Dependent Claim
19 words
A method according to claim 4, wherein the thin layer has a thickness of less than about 0.2 mm.
Claim 7
Dependent Claim
18 words
A method according to claim 1, wherein the alkaline environment is formed by a soluble alkaline producing substance.
Claim 8
Dependent Claim
17 words
A method according to claim 6, wherein the soluble alkaline producing substance comprises an alkali metal hydroxide.
Claim 9
Dependent Claim
17 words
A method according to claim 7, wherein the alkali metal hydroxide comprises sodium hydroxide or lithium hydroxide.
Claim 10
Dependent Claim
20 words
A method according to claim 7, wherein the hydroxide is present at a concentration of at least about 1 molar.
Claim 11
Dependent Claim
21 words
A method according to claim 9, wherein the hydroxide is present at a concentration of not greater than about 5 molar.
Claim 12
Dependent Claim
16 words
A method according to claim 1, wherein the aqueous solution comprises a sample of silage liquor.
Claim 13
Dependent Claim
21 words
A method according to claim 1, wherein the reducing sugars content in the solution is not more than about 50 mM.
Claim 14
Dependent Claim
22 words
A method according to claim 12, wherein the reducing sugars content in the solution is in the range 0 to 25 mM.
Claim 15
Dependent Claim
39 words
A method according to claim 1, carried out in a thin layer electrochemical measurement device, an inner surface of which has a coating of at least one soluble redox mediator, the device including means for producing an alkaline environment.
Claim 16
Dependent Claim
17 words
A method according to claim 14, wherein the soluble redox mediator includes a soluble alkaline producing substance.
Claim 17
Dependent Claim
17 words
A method according to claim 15, wherein the soluble alkaline producing substance comprises an alkali metal hydroxide.
Claim 18
Dependent Claim
27 words
The method according to claim 1, wherein the concentration of hydroxyl ions is adjusted depending on the approximate expected sugar concentration range of the solution being tested.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2000-07-07 | 2001-01-06 | 2001-07-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2004-07-07 | 2005-01-06 | 2005-07-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2008-07-07 | 2009-01-06 | 2009-07-08 | $7700.00 | Window Closed / Lapsed |