US5135718A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Apparatus for simultaneously analyzing vanillylmandelic acid, homovanillic acid and creatinine
Assignee: Tosoh Corp
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Filing: 1991-03-11
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Granted: 1992-08-04
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Expires: 2011-03-11
Abstract
Abstract A method for analyzing vanillylmandelic acid, homovanillic acid and creatinine by fast liquid chromatography, which includes a step of introducing a test solution containing vanillylmandelic acid, homovanillic acid and creatinine to a cation exchange resin column and separating creatinine from vanillylmandelic acid and homovanillic acid; a step of separating by a separation column vanillylmandelic acid and homovanillic acid in the test solution from which creatinine has been separated; and a step of detecting each component.
Inventors
- 👤 Seiji Kawaguchi
- 👤 Hiroaki Takahashi
- 👤 Yuji Saito
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 03:19
CPC Classifications
G; G01; G01N; G01N33/00; G01N33/48; G01N33/50; G01N33/53; G01N33/5308; G01N33/575; G01N33/94; G01N33/9406; G01N30/00; G01N30/02; G01N30/88; G01N2030/8809; G01N2030/8813
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
259 words
An apparatus for analyzing a test solution comprising vanillylmandelic acid, homovanillic acid and creatinine and other acidic components by fast liquid chromatography, which comprises a cation exchange resin column means for separating creatinine from vanillylmandelic acid and homovanillic acid in a test solution, an anion exchange column means for partially fractionating vanillylmandelic acid and homovanillic acid from other acidic components, a separation column means for separating vanillylmandelic acid and homovanillic acid, a first detector means for detecting creatinine, a second detector means for detecting vanillylmandelic acid and homovanillic acid, a first flow path switching valve means for changing the path of eluent from a first path directing said eluent into said cation exchange resin column means to a second path preventing said eluent from entering said cation exchange resin column means, and a second flow path switching valve means for changing the path of eluent from a third path directing said eluent into said anion exchange resin column means to a fourth path preventing said eluent from entering said anion exchange resin column means, wherein said first switching valve means, said cation exchange resin column means and said first detector means are connected sequentially in series to define a flow system means for separating and detecting creatinine, and said first switching valve means, said cation exchange resin column means, said second switching valve means, said anion exchange resin column means, said separation column means and said second detector means are connected sequentially in series to define a flow system means for separating and detecting vanillylmandelic acid and homovanillic acid.
Claim 2
Independent Claim
259 words
An apparatus for analyzing a test solution comprising vanillylmandelic acid, homovanillic acid and creatinine and other acidic components by fast liquid chromatography, which comprises a cation exchange resin column means for separating creatinine from vanillylmandelic acid and homovanillic acid in a test solution, an anion exchange column means for partially fractionating vanillylmandelic acid and homovanillic acid from other acidic components, a separation column means for separating vanillylmandelic acid and homovanillic acid, a first detector means for detecting creatinine, a second detector means for detecting vanillylmandelic acid and homovanillic acid, a first flow path switching valve means for changing the path of eluent from a first path directing said eluent into said cation exchange resin column means to a second path preventing said eluent from entering said cation exchange resin column means, and a second flow path switching valve means for changing the path of eluent from a third path directing said eluent into said anion exchange resin column means to a fourth path preventing said eluent from entering said anion exchange resin column means, wherein said first switching valve means, said cation exchange resin column means and said first detector means are connected sequentially in series to define a flow system means for separating and detecting creatinine, and said first switching valve means, said cation exchange resin column means, said second switching valve means, said anion exchange resin column means, said separation column means and said second detector means are connected sequentially in series to define a flow system means for separating and detecting vanillylmandelic acid and homovanillic acid.
Claim 3
Dependent Claim
21 words
An apparatus according to claim 1, wherein said first and second switching valve means comprise a four-way or a six-way valve.
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) | 1995-08-04 | 1996-02-03 | 1996-08-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-08-04 | 2000-02-03 | 2000-08-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-08-04 | 2004-02-03 | 2004-08-04 | $7700.00 | Window Closed / Lapsed |