US3847550A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Differential chromatographic method
Assignee: United States Atomic Energy Commission
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Filing: 1973-03-27
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Granted: 1974-11-12
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Expires: 1993-03-27
Abstract
Abstract A method for carrying out differential chromatography by simultaneously introducing samples and eluent into at least two parallel chromatographic columns, photometrically monitoring the outflow from the columns, electronically subtracting the output of one photometer from that of another and plotting the difference as a function of time.
Inventors
- 👤 C Scott
- 👤 W Pitt
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 18:40
CPC Classifications
G; G01; G01N; G01N30/00; G01N30/02; G01N30/26; G01N30/38; G01N30/46; G01N30/466; G01N30/467; G01N30/86; G01N30/8603; G01N30/861; G01N30/04; G01N30/16; G01N30/20; G01N2030/201; G01N30/96
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
55 words
A METHOD FOR CARRYING OUT DIFFERENT CHROMATOGRAPHY COMPRISING THE STEPS OF: FLOWING ELUENT THROUGH AT LEAST TWO SUBSTANTIALLY IDENTICALLY PACKED CHROMATOGRAPHIC COLUMNS AT SUBSTANTIALLY THE SAME FLOW RATES; SIMULTANEOUSLY INTRODUCING SUBSTANTIALLY EQUAL VOLUMES OF SAMPLES INTO THE ELUENT FLOW STREAMS; MAINTAINING SAID COLUMNS AT SUBSTANTIALLY THE SAME TEMPERATURE; PHOTOMETRICALLY MONITORING THE OUTFLOW FROM EACH COLUMN
Claim 2
Independent Claim
55 words
A METHOD FOR CARRYING OUT DIFFERENT CHROMATOGRAPHY COMPRISING THE STEPS OF: FLOWING ELUENT THROUGH AT LEAST TWO SUBSTANTIALLY IDENTICALLY PACKED CHROMATOGRAPHIC COLUMNS AT SUBSTANTIALLY THE SAME FLOW RATES; SIMULTANEOUSLY INTRODUCING SUBSTANTIALLY EQUAL VOLUMES OF SAMPLES INTO THE ELUENT FLOW STREAMS; MAINTAINING SAID COLUMNS AT SUBSTANTIALLY THE SAME TEMPERATURE; PHOTOMETRICALLY MONITORING THE OUTFLOW FROM EACH COLUMN
Claim 3
Dependent Claim
37 words
The method according to claim 1 wherein said columns are identically packed by forcing a slurry of chemical separation particles into said columns at a velocity which is greater than the natural settling velocity of said particles.
Claim 4
Dependent Claim
27 words
The method according to claim 1 wherein said columns are packed with chemical separation particles selected from the group consisting of ion exchange resins and selective sorbents.
Claim 5
Dependent Claim
19 words
The method according to claim 3 wherein said particles are within a size range of 10 to 40 microns.
Claim 6
Dependent Claim
19 words
The method according to claim 4 wherein said particles are within a size range of 10 to 15 microns.
Claim 7
Dependent Claim
19 words
The method according to claim 1 including the further step of plotting individual chromatograms for each of said columns.
Claim 8
Dependent Claim
14 words
The method according to claim 1 wherein said eluent increases in concentration over time.
Claim 9
Dependent Claim
14 words
The method according to claim 1 wherein said samples are two different urine specimens.
Claim 10
Dependent Claim
20 words
The method according to claim 1 wherein said columns and flowing eluent are maintained at a pressure greater than atmospheric.
References Cited (Backward Citations)
US3341299A
Cited
US3399972A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-11-11 | 1978-05-13 | 1978-11-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-11-11 | 1982-05-13 | 1982-11-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-11-11 | 1986-05-13 | 1986-11-12 | $7700.00 | Window Closed / Lapsed |