Nuclear magnetic resonance, NMR spectrometry

Nuclear magnetic resonance (NMR) spectrometry has seldom been used as a quantitative analytical method but can have some practical importance in the characterization of surfactants [296-298]. 13C-NMR spectrometry has been used for the qualitative and also quantitative analysis of dodecyl, tetradecyl, and cetyl sulfates [299]. H- and, 3C-NMR spectra of sodium dodecyl sulfate are given by Mazumdar [300]. 

Spectroscopic analyses are widely used to identify the components of copolymers. Infrared (IR) spectroscopy is often sufficient to identify the comonomers present and their general concentration. Nuclear magnetic resonance (NMR) spectrometry is a much more sensitive tool for analysis of copolymers that can be used to accurately quantify copolymer compositions and provide some information regarding monomer placement. 

Reorienting a nuclear moment in a magnetic field (Enudear spin) as observed in nuclear magnetic resonance (NMR) spectrometry... 

Nuclear magnetic resonance (NMR) spectrometry [4] Both the 1H NMR and 13C NMR spectra of zaleplon have been obtained in DMSO- as a solvent and using tetramethylsilane as the internal standard (IS). The assignments for both the 1H and 13C NMR spectra make use of the following numbering scheme ... 

Nuclear magnetic resonance (NMR) spectrometry is basically another form of absorption spectrometry, akin to IR or UV spectrometry. Under appropriate conditions in a magnetic field, a sample can absorb electromagnetic radiation in the radio frequency (rf) region at frequencies governed by the characteristics of the sample. Absorption is a function of certain nuclei in the molecule. A plot of the frequencies of the absorption peaks versus peak intensities constitutes an NMR spectrum. This chapter covers proton magnetic resonance ( H NMR) spectrometry. 

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. 

The solid fat content of an oil is a measure (in percent) of the amount of solid fat present in the oil at any one temperature. It is measured by means of wide-line nuclear magnetic resonance (NMR) spectrometry after a standard tempering procedure for the samples. 

It is possible to use techniques in which the additives can be determined by direct analysis of the sample, such as nuclear magnetic resonance (NMR) spectrometry, ultraviolet (UV) spectrometry, and UV desorption-mass spectrometry. These techniques are very useful when the concentrations of additives in the polymer are high. However, when additives are present in trace levels, it is necessary to carry out a preliminary extraction/concentration step before analysis. Some of the most common additives used in plastics materials are presented in Table 1. 

Mass spectrometry has particular applications in structure determination (see Chapter 4, Part 2) and is a spectroscopic technique that is usually available in modern chemistry laboratories, together, of course, with infrared (IR), ultraviolet (U V) and nuclear magnetic resonance (NMR) spectrometry. X-ray crystallographic facilities are less commonly accessible. 

Nuclear magnetic resonance (NMR) spectrometry and electrospray ionization mass spectrometry are other techniques used to measure the affinity of a small test molecule (the ligand) bound to a receptor. In varying the collision... 

The most frequently used methods for the unambiguous identification of organophosphorus and carbamate compounds are based on gas chromatography (GC) in combination with mass spectrometry (GC-MS) and/or tandem mass spectrometry (GC-MS/MS), liquid chromatography (LC) coupled with MS, and nuclear magnetic resonance (NMR) spectrometry (18). 

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