Patent US3770735A successfully refreshed from Google Patents.
US3770735A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Ferroin reagent and method of making same
Assignee: Hach Co
•
Filing: 1970-06-24
•
Granted: 1973-11-06
•
Expires: 1990-06-24
Abstract
Abstract 3-(2-PYRIDYL)-5,6-BIS(PHENYLSULFONIC ACID) - 1,2,4-TRIAZINE AND CERTAIN SALTS THEREOF, E.G.-SODIUM, ARE PROVIDED TOGETHER WITH A METHOD FOR FORMING SUCH COMPOUNDS. THESE COMPOUNDS ARE USEFUL AS REAGENTS IN THE SPECTROPHOTOMETRIC DETERMINATION OF IRON IN WATER OR OTHER SOLUTIONS.
Inventors
- 👤 L Stookey
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 20:32
CPC Classifications
G; G01; G01N; G01N31/00; G01N31/22
Claims Analysis
Total Claims: 0
No claims parsed yet. Click Sync Now above to re-index claims from Google Patents.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-11-05 | 1977-05-07 | 1977-11-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-11-05 | 1981-05-07 | 1981-11-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-11-05 | 1985-05-07 | 1985-11-06 | $7700.00 | Window Closed / Lapsed |