6533b873fe1ef96bd12d57c6
RESEARCH PRODUCT
Precise measurement of 1H 90° pulse in solid-state NMR spectroscopy for complex and heterogeneous molecular systems
Pellegrino ConteAlessandro Piccolosubject
Magnetic Resonance SpectroscopyMagic angleChemistrySettore AGR/13 - Chimica AgrariaAnalytical chemistryReproducibility of ResultsNuclear magnetic resonance spectroscopyBiochemistryAnalytical ChemistryPulse (physics)Liquid stateSolid-state nuclear magnetic resonanceCalibrationCross polarization magic angle spinning NMR 1H 90° pulse Pulse calibration Circuit impedance Complex molecular systemsCalibrationSpectroscopyElectrical impedancedescription
The 90 degrees pulse calibration is essential in NMR spectroscopy to prevent artefacts in the liquid state or to enhance cross-polarization efficiency in the solid state. We verified pulse-angle (PA) errors due to circuit impedances in solid-state NMR and suggested a possible solution to prevent the inconvenience of PA errors. The classic pulse sequences used to calibrate (1)H 90 degrees pulse lengths by direct detection of protons or by cross-polarization were modified in order to replace single (1)H pulses with (1)H pulse trains. Pulse trains were found to decrease the effect of PA imperfections in the calibration of basic pulses (i.e. 90 degrees and 180 degrees ) for a number of organic substrates. The modified sequences are especially important to rapidly obtain pulse calibration of complex and heterogeneous molecular systems such as humic substances, which usually require a long time when using single (1)H pulses.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 2007-01-01 | Analytical and Bioanalytical Chemistry |