US4348286A
Expired / Lapsed
US
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Large sample thin layer chromatography
Assignee: Analtech Inc
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Filing: 1981-07-17
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Granted: 1982-09-07
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Expires: 2001-07-17
Abstract
Abstract In thin layer chromatographic plates comprising adsorbent layers characterized by adsorptivity which increases from a first edge to the edge opposite, as, for example, in wedge layer plates, resolution is improved by development in the direction of increasing adsorptivity.
Inventors
- 👤 Herman R. Felton
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 09:26
CPC Classifications
G; G01; G01N; G01N30/00; G01N30/90; G01N30/92; G01N30/93; B; B01; B01D; B01D15/00; B01D15/08; B01D15/10; B01D15/20
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
74 words
In the process of resolving the components of a sample on a thin layer chromatogram having an absorbent layer characterized by linear increase in absorbent layer thickness from a thin end to a thicker end opposite, the improvement consisting in placing the sample on the absorbent near the thin end and developing said chromatograph in the direction of increasing absorbent layer thickness, whereby to resolve components of both low and high R f values.
Claim 2
Dependent Claim
74 words
In the process of resolving the components of a sample on a thin layer chromatogram having an absorbent layer characterized by linear increase in absorbent layer thickness from a thin end to a thicker end opposite, the improvement consisting in placing the sample on the absorbent near the thin end and developing said chromatograph in the direction of increasing absorbent layer thickness, whereby to resolve components of both low and high R f values.
Claim 3
Dependent Claim
33 words
The process of claim 1 further improved by the use of a preconcentrating zone adjacent to the thin edge of the absorbent, said preconcentrating zone being thicker and less active than the absorbent.
Claim 4
Dependent Claim
47 words
In a thin layer chromatographic plate comprising a wedge layer absorbent having a thick end and a thin end, the improvement consisting in a preconcentrating zone adjacent to the thin end of the wedge layer absorbent, said preconcentrating zone being thicker and less active than the absorbent.
Claim 5
Dependent Claim
47 words
In a thin layer chromatographic plate comprising a wedge layer absorbent having a thick end and a thin end, the improvement consisting in a preconcentrating zone adjacent to the thin end of the wedge layer absorbent, said preconcentrating zone being thicker and less active than the absorbent.
References Cited (Backward Citations)
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1985-09-06 | 1986-03-08 | 1986-09-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-09-06 | 1990-03-08 | 1990-09-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-09-06 | 1994-03-08 | 1994-09-07 | $7700.00 | Window Closed / Lapsed |