Patent US3874794A successfully refreshed from Google Patents.
US3874794A
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US
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Method and apparatus for photometric analysis of substantially colorless components of sample
Assignee: PE Manufacturing GmbH
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Filing: 1973-04-20
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Granted: 1975-04-01
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Expires: 1993-04-20
Abstract
Abstract This is a method for quantative photometric determination of substantially colorless components of a sample by reaction with a color-producing reagent and subsequent determination of the colored reaction product at a specific wavelength. The method is particularly adapted to determined at least two components in the sample, the second of which may require the addition of a second reagent, for example, to chemically ''''free'''' the second component. The technique first measures the optical transmission of a known amount of sample diluted by a known amount of diluent to determine a ''''blank'''' absorbance value; a known quantity of a color-producing reagent is then added in excess and an absorbance value is determined; and finally, a metered quantity of a reagent which frees the combined component is added and a third absorbance value is measured. From there three absorbance values the concentration of each of the two components may be readily determined.
Inventors
- 👤 Albert Schmitt
- 👤 Hans Vogel
- 👤 Toma Tomoff
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 06:07
CPC Classifications
G; G01; G01N; G01N21/00; G01N21/75; G01N21/77; G01N21/78
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
108 words
A METHOD FOR THE QUANTITIATIVE PHOTOMETRIC DETERMINATION OF SUBSTANTIALLY COLORLESS COMPONENTS OF A SAMPLE BY REACTION WITH A COLOR-PRODUCING REAGENT AND SUBSEQUENT DETERMINATION OF THE ABSORBANCE OF THE COLORED REACTION PRODUCT AT A SPECIFIC WAVELENGTH, COMPRISING AS A FIRST GROUP OF STEPS, INTRODUCING A METERED SAMPLE VOLUME INTO A CELL (17) AND DILUTION BY A METERED QUANTITY OF A DILUENT AND AFTER INTIMATE MIXING A FIRST OPTICAL TRANSMISSION VALUE CORRESPONDING TO THE BLANK VALUE IS MEASURED, AND AS A SECOND GROUP OF STEPS, A METERED QUANTITY OF A COLOR-PRODUCING REAGENT IS ADDED TO THE SAMPLE AND DILUENT AND AFTER INTIMATE MIXING A SECOND OPTICAL TRANSMISSION VALUE IS MEASURED.
Claim 2
Independent Claim
108 words
A METHOD FOR THE QUANTITIATIVE PHOTOMETRIC DETERMINATION OF SUBSTANTIALLY COLORLESS COMPONENTS OF A SAMPLE BY REACTION WITH A COLOR-PRODUCING REAGENT AND SUBSEQUENT DETERMINATION OF THE ABSORBANCE OF THE COLORED REACTION PRODUCT AT A SPECIFIC WAVELENGTH, COMPRISING AS A FIRST GROUP OF STEPS, INTRODUCING A METERED SAMPLE VOLUME INTO A CELL (17) AND DILUTION BY A METERED QUANTITY OF A DILUENT AND AFTER INTIMATE MIXING A FIRST OPTICAL TRANSMISSION VALUE CORRESPONDING TO THE BLANK VALUE IS MEASURED, AND AS A SECOND GROUP OF STEPS, A METERED QUANTITY OF A COLOR-PRODUCING REAGENT IS ADDED TO THE SAMPLE AND DILUENT AND AFTER INTIMATE MIXING A SECOND OPTICAL TRANSMISSION VALUE IS MEASURED.
Claim 3
Dependent Claim
69 words
A method as claimed in claim 1 for the determination of at least two components in a sample, a first component being determinable directly and a second component only after adding another reagent, further comprising: a third group of steps, a metered quantity of a second color-producing reagent is added to the sample, diluent and first reagent mixture and after intimate mixing a third optical transmission value is measured.
Claim 4
Dependent Claim
91 words
A method as claimed in the claim 2 for the determination of a sample component present partially in a free and partially in a combined quantity, in which: in said second group of steps, a metered excess quantity of the first color-producing reagent is added and a third transmission value corresponding to the free partial quantity is measured, while in the third group of steps, a metered quantity of another reagent for setting free the combined partial quantity is added and a transmission value corresponding to the total quantity is measured.
Claim 5
Dependent Claim
34 words
A method as claimed in claim 1, in which: from the measured transmission values are computed quantities at least proportional to the respective absorbance (extinction) and concentration values, which may then be directly recorded.
Claim 6
Dependent Claim
29 words
A method as claimed in the claim 4, in which: the change of said quantities at least proportional to the respective absorbance (extinction) and concentration with time is recorded.
Claim 7
Dependent Claim
41 words
A method as claimed in claim 1, in which: the supply of the metered sample and reagent volumes to the cell (17) successively is accomplished in a controlled time sequence, and the intimate mixing and optical measurement are carried out automatically.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-03-31 | 1978-09-30 | 1979-04-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-03-31 | 1982-09-30 | 1983-04-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-03-31 | 1986-09-30 | 1987-04-01 | $7700.00 | Window Closed / Lapsed |