qNMR in Solid State

摘要: Publisher Summary This chapter follows the fundamentals of solid-state nuclear magnetic resonance (NMR). In solution all interactions apart from chemical shift and indirect coupling are averaged to zero by thermal motions molecules. solids, molecules rigid kept together crystal packing forces. NMR spectrum recorded for lines narrow; width at half-height is usually below 1 Hz. Solid-state spectra diluted nuclei, such as C or N, suffer low sensitivity long spin lattice relaxation times. The registration a with several thousand scans delays takes very time acquire. Although now in routine use identification structural studies organic it less frequently used quantitation studies. validation process requires testing linearity, robustness, specificity, selectivity well parameters accuracy: measurement uncertainty, repeatability, comparability. Quantitative measurements can be performed using synthetic signal an intensity reference, i.e., calibration circuit response through low-power pulse injected during acquisition. Analytical methods based on becoming increasingly popular; one gain quantitative near-quantitative results various types materials: foods, soil, plant, other naturally derived samples. spectroscopy simple reliable means quantifying substance, no matter whether exists pure drug dosage forms.