US3615228A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Glucose determination method employing orthotoluidine
Assignee: Dow Chemical Co
•
Filing: 1969-11-20
•
Granted: 1971-10-26
•
Expires: 1989-11-20
Abstract
Abstract An improved orthotoluidine reagent composition for use in determination of glucose in biological fluids effective sufficient hydrazine to provide a uniform intensity of color when the composition is reacted with a predetermined amount of glucose, such as a standard solution.
Inventors
- 👤 Bernard J Thiegs
- 👤 Robert F Mack
- 👤 John Di Giorgio
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 22:23
CPC Classifications
G; G01; G01N; G01N33/00; G01N33/48; G01N33/50; G01N33/66; Y; Y10; Y10T; Y10T436/00; Y10T436/14; Y10T436/142222; Y10T436/143333; Y10T436/144444
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
35 words
The method of claim 1 wherein the hydrazine is added in an amount sufficient to provide a hydrazine concentration of from about 60 to about 200 micromoles of hydrazine per 100 milliliters of reagent composition.
Claim 2
Dependent Claim
16 words
The method of claim 1 wherein the hydrazine is added in the form of hydrazine hydrate.
Claim 3
Dependent Claim
39 words
The method of claim 1 wherein the reagent composition is prepared by mixing together orthotoluidine, thiourea and glacial acetic acid in predetermined amounts, and wherein the hydrazine is mixed with the orthotoluidine prior to preparation of the reagent composition.
Claim 4
Dependent Claim
29 words
The method of claim 4 wherein the hydrazine is employed in an amount sufficient to provide from about 9 to about 20 micromoles of hydrazine per gram of orthotoluidine.
Claim 5
Dependent Claim
92 words
In a reagent composition useful for determination of glucose by measuring the intensity of color produced by the reaction of glucose with orthotoluidine comprising a solution of orthotoluidine in glacial acetic acid, the concentration of orthotoluidine being from about 5 to about 10 grams of orthotoluidine per 100 milliliters of said solution; the improvement wherein the reagent composition further comprises from about 9 to about 20 micromoles of hydrazine per gram of orthotoluidine, said hydrazine being sufficient to decrease the intensity of the color produced when said composition is reacted with glucose.
Claim 6
Dependent Claim
16 words
The composition of claim 6 further comprising from about 0.1 to about 1 gram of thiourea.
Claim 7
Dependent Claim
41 words
The composition of claim 6 wherein the composition consists essentially of about 9 grams of orthotoluidine and about 0.5 gram of thiourea per 100 milliliters of composition and contains from about 80 to about 180 micromoles of hydrazine per 100 milliliters.
Claim 8
Dependent Claim
73 words
The composition of claim 8 further comprising from about 1.8 to about 2.1 milligrams of glucose per 100 milliliters, and wherein said hydrazine is present in an amount sufficient to decrease the intensity of color obtained by reaction of said glucose with said orthotoluidine to provide an intensity of said color equivalent to an absorbance of from about 0.30 to about 0.34 for light having a wavelength of from 590 to 620 millimicrons.
References Cited (Backward Citations)
US3536448A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-10-25 | 1975-04-26 | 1975-10-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-10-25 | 1979-04-26 | 1979-10-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-10-25 | 1983-04-26 | 1983-10-26 | $7700.00 | Window Closed / Lapsed |