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US4483374A
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US
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Chromatographic column
Assignee: Ethyl Corp
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Filing: 1982-11-01
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Granted: 1984-11-20
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Expires: 2002-11-01
Abstract
Abstract A method is provided for packing a high pressure liquid chromatographic column to obtain increased efficiency by suspending the packing in an alcohol medium between a lower liquid phase (e.g. carbon tetrachloride) and an upper liquid phase (e.g. isooctane) and passing the liquids under high pressure through an unpacked column lower layer first. The packing is retained in the column.
Inventors
- 👤 Chester C. Siemion
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 22:47
CPC Classifications
G; G01; G01N; G01N30/00; G01N30/02; G01N30/50; G01N30/56; G01N30/62; G01N2030/562; G01N2030/565
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
163 words
A method for packing a high pressure liquid chromatographic column to obtain increased efficiency, said method comprising (a) suspending a column packing material in an alcohol medium to obtain a liquid packing suspension, said alcohol having a density similar to the density of said packing material, (b) forming a packing fluid comprising a lower liquid phase, a middle liquid phase and an upper liquid phase, said lower liquid phase having a density greater than said middle liquid phase, said middle liquid phase consisting of said liquid packing suspension, said upper liquid phase being an inert liquid having a density lower than said middle liquid phase and being substantially immiscible with said middle liquid phase, (c) rapidly injecting said packing fluid downwardly under high pressure into the inlet of an unpacked chromatographic column having an inlet and an outlet end, said column having retainer means at said outlet end which retain said packing material in said chromatographic column and permit liquids to pass through.
Claim 2
Independent Claim
163 words
A method for packing a high pressure liquid chromatographic column to obtain increased efficiency, said method comprising (a) suspending a column packing material in an alcohol medium to obtain a liquid packing suspension, said alcohol having a density similar to the density of said packing material, (b) forming a packing fluid comprising a lower liquid phase, a middle liquid phase and an upper liquid phase, said lower liquid phase having a density greater than said middle liquid phase, said middle liquid phase consisting of said liquid packing suspension, said upper liquid phase being an inert liquid having a density lower than said middle liquid phase and being substantially immiscible with said middle liquid phase, (c) rapidly injecting said packing fluid downwardly under high pressure into the inlet of an unpacked chromatographic column having an inlet and an outlet end, said column having retainer means at said outlet end which retain said packing material in said chromatographic column and permit liquids to pass through.
Claim 3
Dependent Claim
11 words
A method of claim 1 wherein said alcohol medium is isopropanol.
Claim 4
Dependent Claim
13 words
A method of claim 2 wherein said lower liquid phase is carbon tetrachloride.
Claim 5
Dependent Claim
25 words
A method of claim 3 wherein said upper liquid phase is a liquid hydrocarbon having a boiling point within the range of about 50°-200° C.
Claim 6
Dependent Claim
11 words
A method of claim 4 wherein said liquid hydrocarbon is isooctane.
Claim 7
Dependent Claim
15 words
A high efficiency high pressure liquid chromatographic column made by the method of claim 1.
References Cited (Backward Citations)
US3080746A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-11-20 | 1988-05-21 | 1988-11-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-11-20 | 1992-05-21 | 1992-11-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-11-20 | 1996-05-21 | 1996-11-20 | $7700.00 | Window Closed / Lapsed |