Practical and technical aspect of High-Resolution NMR: Preparation, Acquisition and analysis.
Preparing the spectrometer: LOCK , Tuning/Matching, Shimming. Gradient Shimming.
- Acquisition of a NMR spectrum
Radiofrequency pulses: Beats theory, rotating vectors model; pulsewidth, relationship between excitation band and pulsewidth. Pulse amplitude and nutation.
Vector nutation for Nuclear Magnetic moment; Rotating frame; Vectors precession in the rotating frame. Interaction between radiation and nuclear magnetic moment. Precession vs nutation in the rotating frame. Pulse calibration; power and attenuation of a pulse; on-resonance e off-resonance conditions.
NMR signal observation: probe-receiver system. Mixer and filter for radiofrequency. Quadrature detection.
Signal sampling. ADC: function, sensitivity and resolution. Nyquist condition. Acquisition time, digital resolution. Receiver Gain.
- NMR spectrum Processing
Fourier transform: theory and application in NMR. FT and quadrature detection. FT, transverse relaxation (T2) and linewidth. Phase correction. Apodization functions. Phase cycle(CYCLOPS).
- Advanced topics
Dephasing mechanisms on the xy plane: chemical shift; J-coupling; homogeneous and inhomogeneous broadening. spin-echo and gradient spin-echo sequences.
Transverse nuclear relaxation: Theory and measurement.
Longitudinal nuclear relaxation: Theory and measurement.
Composite pulse sequences: spin-lock and broad-band decoupling.
Selective excitation: Hard pulses vs shaped pulses; sequences using field gradients.
Solvent suppression: presaturation, binomial sequences, field gradient improvement.
Outstanding pulse sequences: J-modulated spin-echo, INEPT, refocused INEPT, DEPT.
Basis of 2D NMR spectroscopy.