US4005983A
Expired / Lapsed
US
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Method and apparatus for colorimetric analysis
Assignee: Individual
•
Filing: 1974-06-21
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Granted: 1977-02-01
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Expires: 1994-06-21
Abstract
Abstract A colorimetric test for water in a vial which is prepacked with Karl-Fischer-Reagent and a colorimeter for direct readout of water content.
Inventors
- 👤 Harald Dahms
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 11:20
CPC Classifications
G; G01; G01N; G01N31/00; G01N31/16; G01N31/168; G01N31/22; G01N31/222
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
101 words
A method for determining the water content of a sample, comprising the steps of: measuring the optical density of a known volume of first KF reagent, said KF reagent having an optical density which is substantially linearly related to the amount of water added thereto, adding a sample containing an unknown amount of water to said KF reagents measuring the optical density of said KF reagent after addition thereto of said sample containing an unknown amount of water, and determining the amount of water in said sample using said linear relationship between optical density and water content of said KF reagent.
Claim 2
Independent Claim
101 words
A method for determining the water content of a sample, comprising the steps of: measuring the optical density of a known volume of first KF reagent, said KF reagent having an optical density which is substantially linearly related to the amount of water added thereto, adding a sample containing an unknown amount of water to said KF reagents measuring the optical density of said KF reagent after addition thereto of said sample containing an unknown amount of water, and determining the amount of water in said sample using said linear relationship between optical density and water content of said KF reagent.
Claim 3
Dependent Claim
11 words
The method of claim 1, where said sample is a liquid.
Claim 4
Dependent Claim
11 words
The method of claim 1, where said sample is a solid.
Claim 5
Dependent Claim
11 words
The method of claim 1, where said sample is a gas.
Claim 6
Dependent Claim
70 words
The method of claim 1, wherein the water content of a second sample is determined by measuring the optical density of a KF solution having the same composition as said first KF reagent, adding a sample containing an unknown amount of water to said KF solution, and calculating the amount of water in said sample using the linear relationship between optical density and water content of said first KF reagent.
Claim 7
Independent Claim
118 words
A method for determining the amount of water in a sample, comprising the steps of: selecting a KF reagent whose optical density σ is related to the amount (X) of water added to said reagent by the expression σ =MX + B over a range of X, where the value B is a constant and the slope M is a constant which has been determined. adding said sample containing an unknown amount of water therein to said first KF reagent, measuring the optical density of said first KF reagent with said sample added thereto, and determining the amount of water in said sample using the slope M relating water content X to optical density σ of said reagent.
Claim 8
Independent Claim
118 words
A method for determining the amount of water in a sample, comprising the steps of: selecting a KF reagent whose optical density σ is related to the amount (X) of water added to said reagent by the expression σ =MX + B over a range of X, where the value B is a constant and the slope M is a constant which has been determined. adding said sample containing an unknown amount of water therein to said first KF reagent, measuring the optical density of said first KF reagent with said sample added thereto, and determining the amount of water in said sample using the slope M relating water content X to optical density σ of said reagent.
Claim 9
Independent Claim
94 words
A method for determining the strength of a KF reagent, comprising the steps of: selecting a KF reagent which exhibits a substantially linear relationship between its optical density and the amount of water added thereto over a range of water, measuring the optical density of said KF reagent, and establishing its strength, said strength being the amount of water which must be added to said KF reagent to consume the entire amount of said KF reagent, using said linear relationship established between said optical density and the amount of water added to said reagent.
Claim 10
Independent Claim
94 words
A method for determining the strength of a KF reagent, comprising the steps of: selecting a KF reagent which exhibits a substantially linear relationship between its optical density and the amount of water added thereto over a range of water, measuring the optical density of said KF reagent, and establishing its strength, said strength being the amount of water which must be added to said KF reagent to consume the entire amount of said KF reagent, using said linear relationship established between said optical density and the amount of water added to said reagent.
References Cited (Backward Citations)
US2395489A
Cited
US3476516A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1980-02-01 | 1980-08-02 | 1981-02-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-02-01 | 1984-08-02 | 1985-02-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-02-01 | 1988-08-02 | 1989-02-01 | $7700.00 | Window Closed / Lapsed |