US4468331A
Expired / Lapsed
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Method and system for liquid choromatography separations
Assignee: ANSPEC COMPANY Inc 50 ENTERPRISE DRIVE ANN ARBOR MICHIGAN 48107 A CORP OF MICHIGAN
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Filing: 1982-09-13
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Granted: 1984-08-28
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Expires: 2002-09-13
Abstract
Abstract A microprocessor-based analytical liquid chromatograph is programmed to run automatically a series of experiments on a sample mixture using four solvents to determine the solvent strengths and composition needed to optimize resolution.
Inventors
- 👤 Paul E. Antle
- 👤 John A. Schmit
- 👤 Edward L. Smith
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 03:21
CPC Classifications
G; G01; G01N; G01N30/00; G01N30/02; G01N30/26; G01N30/28; G01N30/36; B; B01; B01D; B01D15/00; B01D15/08; B01D15/10; B01D15/16; B01D15/166; G01N30/34; B01D15/26; B01D15/32; B01D15/322; B01D15/325; G01N30/86; G01N30/8658
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
216 words
A method for automatically effecting liquid chromatography separations of a multicomponent sample using a mobile phase having three selectivity adjusting solvents and using a liquid chromatograph column having an automatic sampler module for introducing samples into the column comprising the steps of: selecting three solvents each contributing to a different one of the factors proton acceptor, proton donor, dipole interaction which contribute to total mobile phase selectivity along with a strength adjusting solvent for either reversed phase or normal phase chromatographic separations; effecting a chromatographic separation of the sample under a gradient condition which adjusts the strength of one of said three selectivity adjusting solvents with said strength adjusting solvent; calculating, based upon the retention time of the last sample component in the gradient run, the binary solvent composition E 1 necessary to obtain the desired retention factor k' in an isocratic separation; calculating the equivalent mobile phase strengths for the remaining two binary solvent mobile phases; effecting successive separations of the sample and each component thereof utilizing the three defined solvents at their calculated strengths; utilizing blends of the fixed ratios of the three defined binary solvents to provide an overlapping resolution map and to determine the optimum mobile phase composition for obtaining a chosen selectivity; and effecting a sample separation using such optimum composition.
Claim 2
Independent Claim
216 words
A method for automatically effecting liquid chromatography separations of a multicomponent sample using a mobile phase having three selectivity adjusting solvents and using a liquid chromatograph column having an automatic sampler module for introducing samples into the column comprising the steps of: selecting three solvents each contributing to a different one of the factors proton acceptor, proton donor, dipole interaction which contribute to total mobile phase selectivity along with a strength adjusting solvent for either reversed phase or normal phase chromatographic separations; effecting a chromatographic separation of the sample under a gradient condition which adjusts the strength of one of said three selectivity adjusting solvents with said strength adjusting solvent; calculating, based upon the retention time of the last sample component in the gradient run, the binary solvent composition E 1 necessary to obtain the desired retention factor k' in an isocratic separation; calculating the equivalent mobile phase strengths for the remaining two binary solvent mobile phases; effecting successive separations of the sample and each component thereof utilizing the three defined solvents at their calculated strengths; utilizing blends of the fixed ratios of the three defined binary solvents to provide an overlapping resolution map and to determine the optimum mobile phase composition for obtaining a chosen selectivity; and effecting a sample separation using such optimum composition.
Claim 3
Dependent Claim
19 words
The method set forth in claim 1 wherein the optimum composition is selected to provide a chosen resolution level.
Claim 4
Dependent Claim
93 words
The method set forth in claim 1 wherein binary solvent composition E 1 is calculated by determining the logarithmic isocratic retention factor L 1 using the formula L.sub.1 =Ax.sup.3 +Bx.sup.2 +Cx-D where A=0.002 B=-0.061 C=0.630 D=0.577 and X=largest retention time in the gradient run, then calculating the slope D 2 (a line defining the relationship between such retention factor L 1 and solvent strength by the relation D 2 =-0.01613+(0.007L 1 )) and finally determining the isocratic first mobile phase strength E 1 necessary to obtain the desired k' solving the relation ##EQU12##
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) | 1987-08-28 | 1988-02-27 | 1988-08-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-08-28 | 1992-02-27 | 1992-08-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-08-28 | 1996-02-27 | 1996-08-28 | $7700.00 | Window Closed / Lapsed |