Nuclear magnetic resonance and Fourier

Field desorption mass spectrometry [1606], C nuclear magnetic resonance, and fourier-transform infrared spectroscopy [1337] have been used to characterize oil field chemicals, among them, scale inhibitors. Ion... 

DSC is increasingly being applied to the study of epoxy resin cure in combination with other analytical methods such as nuclear magnetic resonance and Fourier transform infra-red spectroscopy, chromatographic methods, and dynamic mechanical or dielectric studies. It is probably as part of such combined investigations that DSC can be used most effectively in basic research, and in quality control and assessment. 

Due to the complexity of DOM fractionation has revealed more detailed information on the structural subunits prior to the application of advanced analytical methods. Most effective is the combination of different spectroscopic methods using UV-vis absorbance, fluorescence, 1H- and 13C-nuclear magnetic resonance, and Fourier transform-infrared (FT-IR) spectroscopy. In some studies, also electron paramagnetic resonance spectroscopy (EPR) is used (e.g., Chen et al., 2002). 

Usami, T., Itih, T., Ohtani, H., Tsuge, S. (1990) Structural study of polyacrylonitrile libers during oxidative thermal degradation by pyrolysis-gas chromatography, solid state 13C Nuclear magnetic resonance and Fourier transform infrared spectroscopy, Macromolecules 23, 2460-2465. 

There are many other characterization methods (e.g., small-angle X-ray scattering, solid-state nuclear magnetic resonance, and Fourier-transformed infrared analysis) for investigating nanocomposite structure. These techniques are extensively reviewed in Ray and Okamoto. ... 

Mesoporous alumina samples have been synthesized using poly(ethylene oxide)-based nonionic surfactants. The effect that the addition of n-alkylamines to the synthesis gel has on the texture and thermal stability of mesoporous aluminas is studied. Textural and structural characterization using nitrogen adsorption, powder X-ray diffraction, a1 nuclear magnetic resonance and Fourier Transform infrared spectroscopy, as well as catalytic n-hexane hydroisomerization tests are performed. 

R., A Study of Carbon and Hydrogen Aromaticity in Coals by High Resolution Solid State Nuclear Magnetic Resonance and Fourier Transform IR Spectroscopy, (to be published)... 

Figure 12.39 Series of transmission FTIR spectra for (a) Nikkoso precursor AN/MA/ITA, (b) Oxidized in air for 20 min 215°C/15 min 235°C, (c) Oxidized in air for 20 min 215°C/180 min 235°C, (d) Oxidized in air for 20 min 215°C/1800 min 235°C. Source Reprinted from UsamlT, ItohT, Ohtani H.Tsuge S, Structural study of polyacrylonitrile fibers during oxidative thermal degradation by Pyrolysis— Gas Chromatography, Solid State C Nuclear Magnetic Resonance and Fourier Transform Infrared Spectroscopy, Macromolecules, 23, 2460-2465, 1990.

Usami T, Itoh T, Ohtani H, Tsuge S, Structural study of polyacrylonitrile fibers during oxidative thermal degradation by Pyrolysis—Gas Chromatography, Sohd State C Nuclear Magnetic Resonance and Fourier Transform Infrared Spectroscopy, Macromolecules, 23, 2460 2465, 1990. 

Ludlow, M., Louden, D., Handley, A., Taylor, S., Wright, B., and Wilson, I.D., Size-exclusion chromatography with on-line ultraviolet, proton nuclear magnetic resonance, and mass spectrometric detection and on-line collection for off-line Fourier transform infrared spectroscopy, /. Chromatogr. A, 857,89,1999. 

The mechanism of bound residue formation is better understood today due to the use of advanced extraction, analytic, and mainly spectroscopic techniques (e.g., electron spin resonance, ESR nuclear magnetic resonance, NMR Fourier transform infrared spectroscopy), methods that are applied without changing the chemical nature of the residues. 

One of the principal contributions of electronic data processing over the past several years in terms of chemical analysis is the saving of manual effort in interpreting analytical data. Special techniques, such as Fourier transform, have increased speed (as well as sensitivity) by orders of magnitude in connection with infrared, nuclear magnetic resonance, and mass spectroscopy, Of course, for on-line process analyses, essentially instantaneous interpretation is required to provide the proper error signal that is used to position the final control element (valve, feeder, damper, etc.). 

It is unreahstic to attempt the use of the Fourier series or of the Fourier integral transforms without the aid of a computer. In recent years a fast Fourier transform (FFT) algorithm for computers has become widely used. This is particularly useful in certain kinds of chemical instrumentation, specifically nuclear magnetic resonance and infrared absorption spectrometers. In such instruments the experimental observations are obtained directly in the form of a Fourier transform of the desired spectrum a computer that is built into the instrument performs the FFT and yields the spectrum (see Chapter XIX). 

One of the attractions of SFC is that it can use both GC- and LC-like detectors, including the almost universal flame ionization detector (FID) for nonvolatile and volatile analytes after separation on either capillary or packed columns. Selective responses could be also obtained from a number of detectors as NPD, ECD, FPD, ultraviolet, Fourier transform infrared, nuclear magnetic resonance, and mass spectrometry. 

PBX-9404 (94% HMX, 3% NC, 3% CEF) was chosen as the base material for hydrolysis, since much of the prior research by LANL was with this explosive formulation. Analysis of the base hydrolysis products required the use of several instruments and techniques including Fourier transform infrared, nuclear magnetic resonance, and mass spectrometers. Product identification included gas, liquid, and solid products. 

Micro and chemical structural analysis, including porosity, bonding, coking X-ray diffraction (XRD) Nuclear magnetic resonance (NMR) Fourier-transform infrared (FTIR) Scanning electron microscopy (SEM) Transmission electron microscopy (TEM) Atomic force microscopy (AFM) Raman spectroscopy Small probe molecule volumetric and gravimetric adsorption... 

The analytical technologies used In metabolomic investigations are nuclear magnetic resonance and mass spectrometry alone or in combination with liquid or gas chromatographic separation of metabolites (243). Other techniques include thin-layer chromatography, Fourier-transform infrared spectrometry, metabolite arrays, and Raman spectroscopy. 

In the references, there are compiled a number of books and reviews dealing with nuclear magnetic resonance and with pulse and Fourier methods in nuclear magnetic resonance. ... 

These considerations serve the purpose to introduce the principles of applying Fourier methods to nuclear magnetic resonance. And it is this type of experiment (pulse methods, recording of an FID signal combined with a Fourier transformation in a computer) which is usually called Fourier transform nuclear magnetic resonance (FTNMR). 

In virtually all types of experiments in which a response is analyzed as a function of frequency (e.g., a spectrum), transform techniques can significantly improve data acquisition and/or data reduction. Research-level nuclear magnetic resonance and infra-red spectra are already obtained almost exclusively by Fourier transform methods, because Fourier transform NMR and IR spectrometers have been commercially available since the late 1960 s. Similar transform techniques are equally valuable (but less well-known) for a wide range of other chemical applications for which commercial instruments are only now becoming available for example, the first commercial Fourier transform mass spectrometer was introduced this year (1981) by Nicolet Instrument Corporation. The purpose of this volume is to acquaint practicing chemists with the basis, advantages, and applications of Fourier, Hadamard, and Hilbert transforms in chemistry. For almost all chapters, the author is the investigator who was the first to apply such methods in that field. 

It is therefore interesting and important to have a look at the results of investigations made in this respect using various techniques, e.g. nuclear magnetic resonance spectroscopy, Fourier transform infrared spectroscopy and electron paramagnetic resonance spectroscopy. The major and overall findings are discussed below. 

Lindman, B., Payal, M.-C., Kamenka, N., Rymden, R., and Stilbs, R, Micelle formation of anionic and cationic surfactants from Fourier transform proton and lithium-7 nuclear magnetic resonance and tracer self-diffusion studies, J. Phys. Chem., 88, 5048, 1984. 

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