US5045790A
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Investigating a sample using NMR
Assignee: Individual
•
Filing: 1988-08-05
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Granted: 1991-09-03
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Expires: 2008-08-05
Abstract
Abstract A method of investigating a sample using nuclear magnetic resonance comprises i) applying a magnetic field across the sample; ii) creating zero quantum coherences (ZQCs) within the sample during a preparation period of duration τ; iii) allowing the zero quantum coherences to evolve for a period of at least NΔ+t 1 , where Δ, t 1 are constant time intervals and N is an integer; iv) at the end of the step iii) applying a cohernece transfer pulse to create single quantum coherences; v) after a period τ, collecting the free induction decay signal from the sample; vi) repeating steps ii) to v) with different values of N; and, vii) combining at least some of the free induction decay (FID) signals collected to generate the FID due to a single ZQC.
Inventors
- 👤 Laurance D. Hall
- 👤 Timothy J. Norwood
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 18:41
CPC Classifications
G; G01; G01R; G01R33/00; G01R33/20; G01R33/44; G01R33/46; G01R33/4608
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
141 words
A method of investigating a sample using nuclear magnetic resonance, the method comprising i) applying a magnetic field across said sample; ii) creating zero quantum coherences (ZQCs) within said sample during a preparation period of duration τ; iii) allowing said zero quantum coherences to evolve for a period of at least NΔ+t 1 , where Δ, t 1 are constant time intervals and N is an integer; iv) at the end of the step iii) applying a coherence transfer pulse to create single quantum coherences whereafter a free induction decay signal is generated; v) after a period τ, collecting said free induction decay signal from said sample; vi) repeating steps ii) to v) with different values of N; and, vii) combining at least some of the free induction decay (FID) signals collected to generate an FID due to a single ZQC.
Claim 2
Independent Claim
141 words
A method of investigating a sample using nuclear magnetic resonance, the method comprising i) applying a magnetic field across said sample; ii) creating zero quantum coherences (ZQCs) within said sample during a preparation period of duration τ; iii) allowing said zero quantum coherences to evolve for a period of at least NΔ+t 1 , where Δ, t 1 are constant time intervals and N is an integer; iv) at the end of the step iii) applying a coherence transfer pulse to create single quantum coherences whereafter a free induction decay signal is generated; v) after a period τ, collecting said free induction decay signal from said sample; vi) repeating steps ii) to v) with different values of N; and, vii) combining at least some of the free induction decay (FID) signals collected to generate an FID due to a single ZQC.
Claim 3
Dependent Claim
79 words
A method according to claim 1, wherein step ii) comprises applying a pulse sequence comprising a 90° radio frequency pulse in an X direction, a relaxation period of duration τ/2, a 180° radio frequency pulse in a Y direction followed by a further relaxation period of duration τ/2 and a final 90° pulse in said X direction, where the magnetic field is applied along a Z direction and said X, Y, and Z directions define an orthogonal coordinate system.
Claim 4
Dependent Claim
27 words
A method according to claim 1, wherein Δ is chosen to be equal to π/ω ZQC , where ω ZQC is the frequency of said single ZQC.
Claim 5
Dependent Claim
26 words
A method according to claim 1, wherein step v) comprises adding the FID signal collected after each step iii) in which N is an odd integer.
Claim 6
Dependent Claim
28 words
A method according to claim 1, wherein steps ii) and v) include applying a 180° radio frequency pulse at a time τ/2 after commencement of the relevant period.
Claim 7
Dependent Claim
41 words
A method according to claim 1, wherein step iii) has a duration of NΔ+τ'+t 1 , an additional pulse α.sub.θ being applied after a time NΔ+τ', wherein 0° <α≦90°, and wherein θ indicates a direction orthogonal to the magnetic field direction.
Claim 8
Independent Claim
107 words
A method of investigating a sample using nuclear magnetic resonance, the method comprising i) applying a magnetic field across said sample; ii) creating zero quantum coherences within said sample during a preparation period of duration τ; iii) after a period τ', subsequent to step ii), applying a first coherence transfer pulse α.sub.θ ; iv) after a further period t 1 , applying a second coherence transfer pulse α.sub.θ1 ; v) after a further period τ", applying a coherence transfer pulse to create single quantum coherences to generate a free induction decay signal; and, vi) after a period τ'" collecting said free induction decay signal from said sample.
Claim 9
Independent Claim
107 words
A method of investigating a sample using nuclear magnetic resonance, the method comprising i) applying a magnetic field across said sample; ii) creating zero quantum coherences within said sample during a preparation period of duration τ; iii) after a period τ', subsequent to step ii), applying a first coherence transfer pulse α.sub.θ ; iv) after a further period t 1 , applying a second coherence transfer pulse α.sub.θ1 ; v) after a further period τ", applying a coherence transfer pulse to create single quantum coherences to generate a free induction decay signal; and, vi) after a period τ'" collecting said free induction decay signal from said sample.
Claim 10
Dependent Claim
10 words
A method according to claim 7, wherein τ═τ'" and τ'═τ".
Claim 11
Dependent Claim
13 words
A method according to claim 7, where α lies between 0° and 180°.
Claim 12
Dependent Claim
26 words
A method according to claim 1 wherein Δ is chosen to be equal to 2τ/ω ZQC , where ω ZQC is the frequency of said ZQC.
References Cited (Backward Citations)
US4238735A
Cited
US4680546A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1994-09-02 | 1995-03-04 | 1995-09-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-09-02 | 1999-03-04 | 1999-09-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-09-02 | 2003-03-04 | 2003-09-03 | $7700.00 | Window Closed / Lapsed |