US3863489A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Analysis of chromatographic peaks by moments
Assignee: Applied Automation Inc
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Filing: 1970-10-19
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Granted: 1975-02-04
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Expires: 1990-10-19
Abstract
Abstract Overlapping peaks in the output of a chromatographic analyzer are resolved by computing the moment of the composite peak and comparing such moment with the corresponding moments of pure samples of the peak constituents.
Inventors
- 👤 Buell O Ayers
- 👤 Edwin K Clardy
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 14:27
CPC Classifications
G; G01; G01N; G01N30/00; G01N30/02; G01N30/86; G01N30/8624
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
179 words
The method of obtaining data useful in determining the relative concentrations of first and second constituents of a fluid mixture by chromatography when said constituents have approximately the same retention times, which method comprises: introducing into a chromatographic analyzer a sample of the fluid mixture, and operating the analyzer to produce a first chromatogram wherein the composition of the analyzer effluent is measured with respect to time; introducing into said analyzer a sample of said first constituent, and operating the analyzer to produce a second chromatogram wherein the composition of the analyzer effluent is measured with respect to time; introducing into said analyzer a sample of said second constituent, and operating the analyzer to produce a thrid chromatogram wherein the composition of the analyzer effluent is measured with respect to time; and computing the moments of the peaks of said constituents in each of said chromatograms with respect to a common reference point of time, whereby a comparison of the resulting moments provides an indication of the relative amounts of said first and second constituents in the first chromatogram.
Claim 2
Independent Claim
179 words
The method of obtaining data useful in determining the relative concentrations of first and second constituents of a fluid mixture by chromatography when said constituents have approximately the same retention times, which method comprises: introducing into a chromatographic analyzer a sample of the fluid mixture, and operating the analyzer to produce a first chromatogram wherein the composition of the analyzer effluent is measured with respect to time; introducing into said analyzer a sample of said first constituent, and operating the analyzer to produce a second chromatogram wherein the composition of the analyzer effluent is measured with respect to time; introducing into said analyzer a sample of said second constituent, and operating the analyzer to produce a thrid chromatogram wherein the composition of the analyzer effluent is measured with respect to time; and computing the moments of the peaks of said constituents in each of said chromatograms with respect to a common reference point of time, whereby a comparison of the resulting moments provides an indication of the relative amounts of said first and second constituents in the first chromatogram.
Claim 3
Dependent Claim
125 words
The method of claim 1 wherein each of said moments is calculated by establishing a reference signal of predetermined magnitude, establishing an output signal from the chromatographic analyzer representative of the respective chromatogram, integrating the reference signal with respect to time and establishing a first signal representative of the resulting integral, multiplying said first signal by said output signal and establishing a second signal representative of the resulting product, integrating said second signal with respect to time and establishing a third signal representative of the resulting integral, integrating said output signal with respect to time and establishing a fourth signal representative of the resulting integral, and dividing the third signal by the fourth signal to establish a final output signal representative of the resulting moment.
Claim 4
Dependent Claim
22 words
The method of claim 1, further comprising computing the percentage of the first constituent in the fluid mixture by the following equation:
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) | 1978-02-03 | 1978-08-05 | 1979-02-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-02-03 | 1982-08-05 | 1983-02-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-02-03 | 1986-08-05 | 1987-02-04 | $7700.00 | Window Closed / Lapsed |