Decoupling sideband resolved NMR spectroscopy (desire)
AssigneeVarian, Inc.
InventorEriks Kupce
Life of this patent
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Abstract
Cycling sidebands arising from broadband decoupling of I-S heteronuclei are separated from the decoupled I spectra investigated in a 2D pulse sequence wherein I excitation 50 is followed after the interval δ+t1 with refocusing π pulse 54 operating on the I spins. After I excitation 50, the JIS coupling is inverted by π pulse 52 and immediately following the π pulse 54, decoupling 56 is turned on and maintained while signal acquisition in the interval t2 is initiated at δ+t1 after pulse 54. Double FT yields a 2D spectrum with sidebands completely displaced to diagonal locii, or alternatively the time domain data may be accumulated into respective t2 locations by effectively summing over t1 to yield a single dimensional spectrum free of cycling sidebands.
Claims8
A pulse sequence method for discriminating between decoupled spectral entities in I-S heteronuclei and spin decoupling spectral artifact, comprising the steps of:
- (a) at time t=0, exciting I spins by application of a 90° resonant pulse at phase φ,
- (b) upon a delay of substantially Δ/2, applying a πxs pulse to S spins at phase x with respect to φ,
- (c) upon a further delay of substantially Δ/2, applying a πx1 pulse to said I spins at phase x with respect to φ and at the conclusion of said πx1 pulse,
- (d) directing decoupling radiation to said S spins and concurrently acquiring a time dependent waveform f(t2), and
- (e) at the conclusion of said acquisition, terminating said decoupling radiation,
- wherein Δ=δ+t1 and δ is substantially equal to the duration of said πxs pulse.
Dependencies are inferred from the claim text.