US4191649A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Liquid chromatography system with simulated gradient
Assignee: Individual
•
Filing: 1978-10-23
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Granted: 1980-03-04
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Expires: 1998-10-23
Abstract
Abstract In a liquid chromatography system a secondary pumping system is disclosed which produces a simulated mobile phase gradient that may be pumped through a reference cell at atmospheric pressure. The secondary pumping system is connected to the primary pumping system so as to maintain the flow at the same rate as in the primary pumping system.
Inventors
- 👤 Richard A. Hartwick
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 08:41
CPC Classifications
G; G01; G01N; G01N30/00; G01N30/02; G01N30/26; G01N30/28; G01N30/34; B; B01; B01D; B01D15/00; B01D15/08; B01D15/10; B01D15/16; B01D15/166; G01N30/32; G01N2030/324
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
101 words
In a liquid chromatography system having a first and second reservoirs for eluent with first and second pumps connected thereto and a first conduit, the discharge of the pumps connected thereto, said conduit connected to a column and sample cell in series, that improvement comprising providing a reference cell, third and fourth pumps, said third and fourth pumps connected to the first and second reservoirs and discharging into a common second conduit, said common second conduit connected to a volume compensator and said reference cell in series, said third and fourth pumps driven in unison with said first and second pumps.
Claim 2
Dependent Claim
101 words
In a liquid chromatography system having a first and second reservoirs for eluent with first and second pumps connected thereto and a first conduit, the discharge of the pumps connected thereto, said conduit connected to a column and sample cell in series, that improvement comprising providing a reference cell, third and fourth pumps, said third and fourth pumps connected to the first and second reservoirs and discharging into a common second conduit, said common second conduit connected to a volume compensator and said reference cell in series, said third and fourth pumps driven in unison with said first and second pumps.
Claim 3
Dependent Claim
22 words
A system as defined in claim 1 wherein said third and fourth pumps are mechanically connected to said first and second pumps.
Claim 4
Dependent Claim
23 words
A system as defined in claim 1 wherein said second conduit includes a volume compensator to reproduce the volume of said first conduit.
Claim 5
Dependent Claim
20 words
A system as defined in claim 1 wherein said reference cell and said sample cell are placed adjacent each other.
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) | 1983-03-04 | 1983-09-03 | 1984-03-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-03-04 | 1987-09-03 | 1988-03-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-03-04 | 1991-09-03 | 1992-03-04 | $7700.00 | Window Closed / Lapsed |