Nuclear magnetic resonance spectrometry defined

The structures of vanicosides A (1) and B (2) and hydropiperoside (3) were established primarily by one- and two-dimensional nuclear magnetic resonance (NMR) spectroscopy techniques and fast atom bombardment (FAB) mass spectrometry (MS).22 The presence of two different types of phenylpropanoid esters in 1 and 2 was established first through the proton (4H) NMR spectra which showed resonances for two different aromatic substitution patterns in the spectrum of each compound. Integration of the aromatic region defined these as three symmetrically substituted phenyl rings, due to three p-coumaryl moieties, and one 1,3,4-trisubstituted phenyl ring, due to a feruloyl ester. The presence of a sucrose backbone was established by two series of coupled protons between 3.2 and 5.7 ppm in the HNMR spectra, particularly the characteristic C-l (anomeric) and C-3 proton doublets... 

C. E. Brown, S. C. Roerig, V. T. Berger, R. B. Cody, and J. M. Fujimoto, "Analgesic Potencies of Morphine 3- and 6-Sulfates After Intracerebroventricular Adminstration in Mice Relationship to Structural Characteristics Defined by Mass Spectrometry and Nuclear Magnetic Resonance," J. Pharm. Sci., 24, 821 (1985). 

In the author s opinion, the better approach to experimentally study the morphology of the silica surface is with the help of physical adsorption (see Chapter 6). Then, with the obtained, adsorption data, some well-defined parameters can be calculated, such as surface area, pore volume, and pore size distribution. This line of attack (see Chapter 4) should be complemented with a study of the morphology of these materials by scanning electron microscopy (SEM), transmission electron microscopy (TEM), scanning probe microscopy (SPM), or atomic force microscopy (AFM), and the characterization of their molecular and supramolecular structure by Fourier transform infrared (FTIR) spectrometry, nuclear magnetic resonance (NMR) spectrometry, thermal methods, and possibly with other methodologies. 

Today, mass spectrometry is a well established tool in analytical organic chemistry. Worldwide, many analytical data are collected daily by mass spectrometry. But at this point, two crucial questions have to be asked (a) Is mass spectrometry really one single, well-defined method and (b) is mass spectrometry in fact a spectroscopic method as it is for instance infrared spectroscopy or nuclear magnetic resonance ... 

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