US4454043A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Column switching procedure
Assignee: Monsanto Co
•
Filing: 1980-11-17
•
Granted: 1984-06-12
•
Expires: 2000-11-17
Abstract
Abstract A method for increasing the capacity of a chromatographic system useful for the quantitative determination of at least one component of interest at a trace level concentration in a multi-component composition.
Inventors
- 👤 Chihyuan C. Ting
- 👤 David F. Tomkins
- 👤 Melvin L. Rueppel
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 16:56
CPC Classifications
G; G01; G01N; G01N30/00; G01N30/02; G01N30/26; G01N30/38; G01N30/46; G01N30/461; G01N30/468
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
189 words
A method of increasing the capacity of a chromatographic system useful for the quantitative determination of at least one component of interest in a multi-component composition at trace level concentration, said method comprising: (a) admixing a portion of said multi-component composition with a first mobile phase carrier to form a chromatographically separable composition; (b) passing said chromatographically separable composition into a first chromatographic separation zone having packing therein thereby forming an eluent of each component of said multi-component composition; (c) retaining in said chromatographic separation system only the eluent of said component of interest; (d) admixing at least one additional mobile phase carrier with said retained eluent of said first chromatographic separation zone to form a diluted retained eluent; (e) passing said retained diluted eluent into a second chromatographic separation zone serially connected to said first chromatographic separation zone having packing therein; (f) passing a second mobile phase carrier into said second chromatographic separation zone thereby forming a purified eluent containing said component of interest in a concentrated form; (g) passing said purified eluent into an analytical detection system whereby the concentration of said component of interest is determined.
Claim 2
Independent Claim
189 words
A method of increasing the capacity of a chromatographic system useful for the quantitative determination of at least one component of interest in a multi-component composition at trace level concentration, said method comprising: (a) admixing a portion of said multi-component composition with a first mobile phase carrier to form a chromatographically separable composition; (b) passing said chromatographically separable composition into a first chromatographic separation zone having packing therein thereby forming an eluent of each component of said multi-component composition; (c) retaining in said chromatographic separation system only the eluent of said component of interest; (d) admixing at least one additional mobile phase carrier with said retained eluent of said first chromatographic separation zone to form a diluted retained eluent; (e) passing said retained diluted eluent into a second chromatographic separation zone serially connected to said first chromatographic separation zone having packing therein; (f) passing a second mobile phase carrier into said second chromatographic separation zone thereby forming a purified eluent containing said component of interest in a concentrated form; (g) passing said purified eluent into an analytical detection system whereby the concentration of said component of interest is determined.
Claim 3
Independent Claim
26 words
The method of claims 1 wherein said trace level is a concentration in the range from about 1 to about 1000 parts per billion by weight.
Claim 4
Dependent Claim
26 words
The method of claim 2 wherein said trace level is a concentration in the range from about 5 to about 100 parts per billion by weight.
Claim 5
Dependent Claim
26 words
The method of claim 3 wherein said portion of said multi-component composition is a sample size in the range from about 0.01 to about 5 milliliters.
Claim 6
Dependent Claim
20 words
The method of claim 4 wherein said sample size is in the range from about 1 to about 2 milliliters.
Claim 7
Dependent Claim
29 words
The method of claim 1 wherein said packing is ion exchange resin selected from the group consisting of polystyrene-divinyl benzene based resin and silica based chemical bonded packing material.
Claim 8
Dependent Claim
16 words
The method of claim 6 wherein said first and said second chromatographic separation zones comprise columns.
Claim 9
Dependent Claim
13 words
The method of claim 7 wherein said chromatographic separation zones comprise metallic columns.
Claim 10
Dependent Claim
16 words
The method of claim 1 wherein said multi-component aqueous solution is an aqueous solution of glyphosate.
Claim 11
Dependent Claim
15 words
The method of claim 1 wherein said multi-component composition comprises an aqueous solution of N-nitrosoamines.
Claim 12
Dependent Claim
21 words
A process of claim 10 wherein said packing employed in said first chromatographic separation zone is an anion ion exchange resin.
Claim 13
Dependent Claim
16 words
A process of claim 11 wherein said anion exchange resin comprises a chloride ion exchange resin.
Claim 14
Dependent Claim
24 words
The method of claim 12 wherein said packing employed in said second chromatographic separation zone is a silica based anion ion exchange packing material.
Claim 15
Dependent Claim
18 words
The method of claim 13 wherein said first mobile phase carrier comprises an aqueous solution of sodium chloride.
Claim 16
Dependent Claim
13 words
The method of claim 14 wherein said additional mobile phase carrier comprises water.
Claim 17
Dependent Claim
21 words
The method of claim 15 wherein said second mobile phase carrier comprises an aqueous solution of KH 2 PO 4 .
Claim 18
Dependent Claim
14 words
The process of claim 10 wherein said N-nitrosoamines comprises a polar substituted alkyl nitrosoamine.
References Cited (Backward Citations)
US3700695A
Cited
US3686117A
Cited
US3977860A
Cited
US3950402A
Cited
US3954848A
Cited
US3966596A
Cited
US4070284A
Cited
US3969398A
Cited
US4073725A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-06-12 | 1987-12-12 | 1988-06-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-06-12 | 1991-12-12 | 1992-06-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-06-12 | 1995-12-12 | 1996-06-12 | $7700.00 | Window Closed / Lapsed |