Indirect detection of nuclear spins of low gyromagentic ratio coupled to spins of high gyromagnetic ratio

Claim 2

In a method of gyromagnetic resonance spectroscopy for indirectly detecting transient gyromagnetic resonances of a first group of gyromagnetic resonators interacting with a second group of gyromagnetic resonators forming heteronuclear spin coupled resonating systems within a sample of matter to be analyzed, said heteronuclear systems exhibiting multiple quantum coherence, the steps of (a) preparing a non-equilibrium resonant statistical state of an assembly of said heteronuclear resonators, said state characterized by nonvanishing zero and double quantum coherence transitions; (b) permitting said non-equilibrium state to evolve for a first interval of time; (c) applying a nonselective 180° pulse of RF energy to said second group whereby heteronuclear zero and double quantum transition amplitures are interchanged; (d) permitting continued evolution of said non-equilibrium state for a further first interval of time; (e) applying a 90° pulse of RF energy to said first group of resonators whereby zero and double quantum coherence in said heteronuclear spin coupled system is converted to single quantum coherence in said second group of gyromagnetic resonance; (f) detecting and recording the free induction decay of said resonators over a second interval of time after application of said conversion pulse; (g) changing said first period of time by an increment thereof and repeating steps a-e inclusive, whereby a two dimensional function of said first and second time interval is developed; (h) double Fourier transforming said function to the frequency domain.

Claim 3

The method of claim 1 wherein said step of detecting comprises applying coherent radiation to said first group of resonators during said second interval of time to decouple said first group of resonators from said second group.

Claim 4

The method of claim 1 wherein said step of detecting comprises permitting said coupled systems to continue to interact following said conversion pulse for a mixing period of time preceding said second interval of time, and applying broad band RF irradiation to said first group of resonators during said second interval of time to decouple said first group of resonators from said second group.

Claim 5

The method of claim 2 or 3 wherein said step of preparing said non-equilibrium statistical state comprises applying a first preparatory 90° RF pulse to said second group of resonators and after a preparatory interval, t p , applying a second preparatory 90° RF pulse to said second group of resonators; applying a 180° pulse to each said groups of resonators at substantially the time 1/2t p with respect to said first preparatory pulse; and applying a 90° RF pulse to said first group of resonators substantially concurrent with said second preparatory pulse.

Claim 6

The method of claim 4 wherein said preparatory interval is approximately the reciprocal of twice the coupling constant characterizing the interaction of said first and second groups of resonators.

Claim 7

The method of claim 5 including the step of destroying any persistent magnetization of said second group of gyromagnetic resonators prior to said step of preparing said non-equilibrium statistical state.

Claim 8

The method of claim 6 further comprising the step of forming a two-dimensional spectral display of said Fourier transformed frequency domain spectral data for resolving and identifying multiplet spectral structures associated with said first group of resonators.

Claim 9

In a method of gyromagnetic resonance spectroscopy for directly detecting transient gyromagnetic resonances of a first group of gyromagnetic resonators interacting with a second group of gyromagnetic resonators forming heteronuclear spin coupled resonating systems within a sample of matter to be analyzed, said heteronuclear systems exhibiting multiple quantum coherences, the steps of (a) preparing a non-equilibrium resonant statistical state of an assembly of said heteronuclear resonators, said state characterized by nonvanishing zero and double quantum coherence transitions; (b) permitting said non-equilibrium state to evolve for a first interval of time t 1 ; (c) applying a 90° pulse of RF energy to said first group of resonators at the conclusion of a preparatory period t p whereafter zero and double quantum coherence in said heteronuclear spin coupled system is converted to single quantum coherence in said second group of gyromagnetic resonators; (d) detecting and recording the free induction decay of said resonances of said second group of resonators over a second interval of time, t 2 , after application of said conversion pulse; (e) changing said first interval of time by an increment thereof and repeating the steps a-e inclusive, whereby a function S (t 1 , t 2 ) is developed; (f) double Fourier transforming said function S (t 1 , t 2 ) to the frequency domain.

Claim 10

In a method of gyromagnetic resonance spectroscopy for directly detecting transient gyromagnetic resonances of a first group of gyromagnetic resonators interacting with a second group of gyromagnetic resonators forming heteronuclear spin coupled resonating systems within a sample of matter to be analyzed, said heteronuclear systems exhibiting multiple quantum coherences, the steps of (a) preparing a non-equilibrium resonant statistical state of an assembly of said heteronuclear resonators, said state characterized by nonvanishing zero and double quantum coherence transitions; (b) permitting said non-equilibrium state to evolve for a first interval of time t 1 ; (c) applying a 90° pulse of RF energy to said first group of resonators at the conclusion of a preparatory period t p whereafter zero and double quantum coherence in said heteronuclear spin coupled system is converted to single quantum coherence in said second group of gyromagnetic resonators; (d) detecting and recording the free induction decay of said resonances of said second group of resonators over a second interval of time, t 2 , after application of said conversion pulse; (e) changing said first interval of time by an increment thereof and repeating the steps a-e inclusive, whereby a function S (t 1 , t 2 ) is developed; (f) double Fourier transforming said function S (t 1 , t 2 ) to the frequency domain.

Claim 11

The method of claim 8 further comprising applying a non-selective 180° pulse of RF energy to said second group, after lapse of one half said first interval of time, whereby heteronuclear zero and double quantum transition amplitudes are interchanged, permitting continued evolution of said non-equilibrium state for a further interval of time equal to one half said first interval of time.

Claim 12

The method of claim 8 wherein said step of detecting comprises applying coherent radiation to said first group of resonators during said second interval of time to decouple said first group of resonators from said second group.

Claim 13

The method of claim 8 wherein said step of detecting comprises permitting said coupled systems to continue to interact following said conversion pulse for a mixing period of time preceding said second interval of time, and applying RF noise radiation to said first group of resonators during said second interval of time to decouple said first group of resonators from said second group.

Claim 14

The method of claim 10 or 11 wherein said step of preparing said non-equilibrium statistical state comprises applying a first preparatory 90° RF pulse to said second group of resonators and after a preparatory interval t p applying a second preparatory pulse to said second group of resonators; applying a 180° pulse to each said groups of resonators at substantially the time t p /2 with respect to said first preparatory pulse; and applying a 90° RF pulse to said first group of resonators substantially concurrent with said second preparatory pulse.

Claim 15

The method of claim 12 wherein said preparatory interval is approximately the reciprocal of twice the coupling constant determining the interaction of said first and second groups of resonators.

Claim 16

The method of claim 13 including the step of destroying any persistent magnetization of said second group of gyromagnetic resonators prior to said step of preparing said non-equilibrium statistical state.

Claim 17

The method of claim 14 further comprising the step of forming a two-dimensional spectral display of said Fourier transformed frequency domain spectral data for resolving and identifying multiplet spectral structures associated with said first group of resonators.

Claim 18

In a method of heteronuclear gyromagnetic resonance spectroscopy wherein spin-spin coupled gyromagnetic resonators are initially prepared to exhibit multiple quantum coherence by application of first and second 90° pulses spaced by an interval of time, said pulses applied to a first group of appropriate resonators and a third 90° pulse applied to a second group of resonators substantially concurrent with said second 90° pulse, the improvement comprising applying a 180° pulse concurrently to each said groups of resonators at substantially the midpoint of said interval of time.

Claim 19

In a method of heteronuclear gyromagnetic resonance spectroscopy wherein spin-spin coupled gyromagnetic resonators are initially prepared to exhibit multiple quantum coherence by application of first and second 90° pulses spaced by an interval of time, said pulses applied to a first group of appropriate resonators and a third 90° pulse applied to a second group of resonators substantially concurrent with said second 90° pulse, the improvement comprising applying a 180° pulse concurrently to each said groups of resonators at substantially the midpoint of said interval of time.

Claim 20

In a method of gyromagnetic resonance spectroscopy for indirectly detecting transient gyromagnetic resonances of a first group of gyromagnetic resonators interacting with a second group of gyromagnetic resonators forming heteronuclear spin coupled resonating systems within a sample of matter to be analyzed, said heteronuclear systems exhibiting multiple quantum coherence, the steps of (a) preparing a non-equilibrium resonant statistical state of an assembly of said heteronuclear resonators, said state characterized by nonvanishing zero and double quantum coherence transitions; (b) permitting said non-equilibrium state to evolve for a first interval of time, (1/2)t 1 ,; (c) applying a nonselective 180° pulse of RF energy to said first group whereby heteronuclear zero and double quantum transition amplitures are interchanged; (d) permitting continued evolution of said non-equilibrium state for a further first interval of time; (e) applying a 90° pulse of RF energy to said second group of resonators whereby zero and double quantum coherence in said heteronuclear spin coupled system is converted to single quantum coherence in said second group of gyromagnetic resonators; (f) detecting and recording the free induction decay of said resonances over a second interval of time after application of said conversion pulse; (g) changing said first period of time by an increment thereof and repeating the steps a-e inclusive, whereby a two-dimensional function of said first and second time interval is developed; (h) double Fourier transforming said function to the frequency domain.

Claim 21

In a method of gyromagnetic resonance spectroscopy for indirectly detecting transient gyromagnetic resonances of a first group of gyromagnetic resonators interacting with a second group of gyromagnetic resonators forming heteronuclear spin coupled resonating systems within a sample of matter to be analyzed, said heteronuclear systems exhibiting multiple quantum coherence, the steps of (a) preparing a non-equilibrium resonant statistical state of an assembly of said heteronuclear resonators, said state characterized by nonvanishing zero and double quantum coherence transitions; (b) permitting said non-equilibrium state to evolve for a first interval of time, (1/2)t 1 ,; (c) applying a nonselective 180° pulse of RF energy to said first group whereby heteronuclear zero and double quantum transition amplitures are interchanged; (d) permitting continued evolution of said non-equilibrium state for a further first interval of time; (e) applying a 90° pulse of RF energy to said second group of resonators whereby zero and double quantum coherence in said heteronuclear spin coupled system is converted to single quantum coherence in said second group of gyromagnetic resonators; (f) detecting and recording the free induction decay of said resonances over a second interval of time after application of said conversion pulse; (g) changing said first period of time by an increment thereof and repeating the steps a-e inclusive, whereby a two-dimensional function of said first and second time interval is developed; (h) double Fourier transforming said function to the frequency domain.

Claim 22

The method of claim 17 wherein said step of detecting comprises applying coherent radiation to said first group of resonators during said second interval of time to decouple said first group of resonators from said second group.

Claim 23

The method of claim 17 wherein said step of detecting comprises permitting said coupled systems to continue to interact following said conversion pulse for a mixing period of time preceding said second interval of time, and applying RF noise radiation to said first group of resonators during said second interval of time to decouple said first group of resonators from said second group.

Claim 24

The method of claim 18 or 19 wherein said step of preparing said non-equilibrium statistical state comprises applying a first preparatory 90° RF pulse to said second group of resonators and after a preparatory interval, t p , applying a second preparatory 90° pulse to said second group of resonators; applying a 180° pulse to each said groups of resonators at substantially the time 1/2t p with respect to said first preparatory pulse; and applying a 90° RF pulse to said first group of resonators substantially concurrent with said second preparatory pulse.

Claim 25

The method of claim 20 wherein said preparatory interval is approximately the reciprocal of twice the coupling constant characterizing the interaction of said first and second groups of resonators.

Claim 26

The method of claim 21 including the step of destroying any persistent magnetization of said second group of gyromagnetic resonators prior to said step of preparing said non-equilibrium statistical state.

Claim 27

The method of claim 27 further comprising the step of forming a two-dimensional spectral display of said Fourier transformed frequency domain spectral data for resolving and identifying multiplet spectral structures associated with said first group of resonators.

Claim 28

In a method of gyromagnetic resonance spectroscopy for directly detecting transient gyromagnetic resonances of a first group of gyromagnetic resonators interacting with a second group of gyromagnetic resonators forming heteronuclear spin coupled resonating systems within a sample of matter to be analyzed, said heteronuclear systems exhibiting multiple quantum coherences, the steps of (a) preparing a non-equilibrium resonant statistical state of an assembly of said heteronuclear resonators, said state characterized by nonvanishing zero and double quantum coherence transitions; (b) permitting said non-equilibrium state to evolve for a first interval of time t 1 ; (c) applying a 90° pulse of RF energy to said second group of resonators at the conclusion of preparatory period t p where zero and double quantum coherence in said heteronuclear spin coupled system is converted to single quantum coherence in said second group of gyromagnetic resonators; (d) detecting and recording the free induction decay of said resonances of said first group of resonators over a second interval of time, t 2 , after application of said conversion pulse; (e) changing said first interval of time by an increment thereof and repeating steps a-e inclusive, whereby a function S (t 1 , t 2 ) is developed; (f) double Fourier transforming said function S (t 1 , t 2 ) to the frequency domain.

Claim 29

In a method of gyromagnetic resonance spectroscopy for directly detecting transient gyromagnetic resonances of a first group of gyromagnetic resonators interacting with a second group of gyromagnetic resonators forming heteronuclear spin coupled resonating systems within a sample of matter to be analyzed, said heteronuclear systems exhibiting multiple quantum coherences, the steps of (a) preparing a non-equilibrium resonant statistical state of an assembly of said heteronuclear resonators, said state characterized by nonvanishing zero and double quantum coherence transitions; (b) permitting said non-equilibrium state to evolve for a first interval of time t 1 ; (c) applying a 90° pulse of RF energy to said second group of resonators at the conclusion of preparatory period t p where zero and double quantum coherence in said heteronuclear spin coupled system is converted to single quantum coherence in said second group of gyromagnetic resonators; (d) detecting and recording the free induction decay of said resonances of said first group of resonators over a second interval of time, t 2 , after application of said conversion pulse; (e) changing said first interval of time by an increment thereof and repeating steps a-e inclusive, whereby a function S (t 1 , t 2 ) is developed; (f) double Fourier transforming said function S (t 1 , t 2 ) to the frequency domain.

Claim 30

The method of claim 24 further comprising applying a non-selective 180° pulse of RF energy to said second group, after lapse of one half said first interval of time, whereby heteronuclear zero and double quantum transition amplitudes are interchanged, `permitting continued evolution of said non-equilibrium state for a further interval of time equal to one half said first interval of time.

Claim 31

The method of claim 24 wherein said step of detecting comprises applying coherent radiation to said second group of resonators during said second interval of time to decouple said second group of resonators from said first group.

Claim 32

The method of claim 24 wherein said step of detecting comprises permitting said coupled systems to continue to interact following said conversion pulse for a mixing period of time preceding said second interval of time, and applying RF noise radiation to said second group of resonators during said second interval of time to decouple said second group of resonators from said first group.

Claim 33

The method of claim 26 or 27 wherein said step of preparing said non-equilibrium statistical state comprises applying a first preparatory 90° RF pulse to said first group of resonators and after said preparatory interval t p applying a second preparatory pulse to said first group of resonators; applying a 180° pulse to each said group of resonators at substantially the time t p /2 with respect to said first preparatory pulse; and applying a 90° RF pulse to said second group of resonators substantially concurrent with said second preparatory pulse.

Claim 34

The method of claim 28 wherein said preparatory interval is approximately the reciprocal of twice the coupling constant determining the interaction of said first and second groups of resonators.

Claim 35

The method of claim 29 including the step of destroying any persistent magnetization of said first group of gyromagnetic resonators prior to said step preparing said non-equilibrium statistical state.

Claim 36

The method of claim 30 further comprising the step of forming a two-dimensional spectral display of said Fourier transformed frequency domain spectral data for resolving and identifying multiplet spectral structures associated with said second group of resonators.