Magnetic quantitative analysis

Instmmental methods of analysis provide information about the specific composition and purity of the amines. QuaUtative information about the identity of the product (functional groups present) and quantitative analysis (amount of various components such as nitrile, amide, acid, and deterruination of unsaturation) can be obtained by infrared analysis. Gas chromatography (gc), with a Hquid phase of either Apiezon grease or Carbowax, and high performance Hquid chromatography (hplc), using siHca columns and solvent systems such as isooctane, methyl tert-huty ether, tetrahydrofuran, and methanol, are used for quantitative analysis of fatty amine mixtures. Nuclear magnetic resonance spectroscopy (nmr), both proton ( H) and carbon-13 ( C), which can be used for quaHtative and quantitative analysis, is an important method used to analyze fatty amines (8,81). 

To further clarify the role of magnetic effects on compressibility, a shock compression experiment was performed on an fee 28.5-at. % Ni sample whose initial temperature was raised to 130°C. As is shown in Table 5.1, the compressibility was found to decrease to a value consistent with the nonmagnetic compressibility. Thus, the sharp change in compressibility, the critical values for the transition, and the magnitudes of the compressibility under the various conditions give a clear demonstration that a second-order magnetic transition has been observed, and we will proceed with a quantitative analysis of the transition. 

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]. 

A quantitative analysis of the magnetic susceptibility was attempted using a more complex spin Hamiltonian ... 

P shows magnetic properties similar to 1H and 19F 31P with l = 1/2 exhibits sharp NMR peaks with chemical shifts extending over range of 700 ppm, 31P NMR has been used in the quantitative analysis of condensed phosphates, hydroxymethyl phosphines and thiophosphates. 

We used the common principles of quantitative analysis of additive properties of alloys developed in work [3].The following equation that describes the magnetic effect during the crystallization of the amorphous alloy Fes2Si2Bi6 was got ... 

Amitay-Rosen T, Cortis A, Berkowitz B (2005) Magnetic resonance imaging and quantitative analysis of particle deposition in porous media. Environ Sci Technol 39 7208-7216 Ashton FM, Sheets TJ (1959) The relationship of soil adsorption of EPTC to oats injury in various soil types. Weeds 7 88-90... 

In this chapter we focus primarily on calibration of LC-MS where the mass spectrometer is operating at unit resolution, resolution that is sufficient to separate two peaks one mass unit apart. This kind of low-resolution mass filter covers almost 90 percent of the instruments commonly used for qualitative and/or quantitative analysis of small molecules. Batch-to-batch qualification testing of the instrument is also described. For the calibration of high-resolution mass spectrometers such as magnetic sector, TOF, or FTICR coupled with liquid chromatography, readers are referred to specific publications. 

Atomic spectra, which historically contributed extensively to the development of the theory of the structure of the atom and led 10 the discovery of the electron and nuclear spin, provide a method of measuring ionization potentials, a method for rapid and sensitive qualitative and quantitative analysis, and data for the determination of the dissociation energy of a diatomic molecule. Information about the type of coupling of electron spin and orbital momenta in the atom can be obtained with an applied magnetic field. Atomic spectra may be used to obtain information about certain regions of interstellar space from the microwave frequency emission by hydrogen and to examine discharges in thermonuclear reactions. 

Modern NMR techniques such as quantitative analysis of multisite exchange using either ID magnetization transfer experiments (JOS) or the 2D exchange spectroscopy (EXSY) method (104,105) promise to be of great help in unraveling the complex stereochemical exchange networks involved in cluster fluxionality. The usefulness of EXSY in the context of this article is illustrated by the phase-sensitive 13C 1H EXSY spectrum (255 K, tm = 0.5 sec)... 

Rubio, F.M., J.A. Itak, A.M. Scutellaro, M.Y. Selisker, and D.P. Herzog (1991). Performance characteristics of a novel magnetic-parti-cle-based enzyme linked immunosorbent assay for the quantitative analysis of atrazine and related triazines in water samples. Food Agric. Immunol., 3 113-125. 

To understand how the CP/MAS experiment can be applied to quantitative analysis, the magnetization transfer and relaxation processes, which directly affect the signal intensity, must be considered. Cross polarization is mediated by H-13C dipolar interactions, so the magnetization buildup will occur at different rates for different types of carbons. In general, the cross polarization rate (Tcp1) increases with the degree of protonation.21 22 That is, TcP is generally shorter for methylene and methine carbons than for quaternary carbons, Fig. 12.6. Motional modulation... 

Clearly, in order to correctly apply CP pulse sequences for quantitative analysis (or even qualitative analysis), many relaxation processes (Tic, T pH, Till. TCp) must be considered and spectral acquisition parameters appropriately set. While a CP spectrum may be obtained when Tic > 7) 11 3TlpH Tqp, a quantitative CP spectrum requires that the recycle delay is sufficient (on the order of Tm) for the protons to be uniformly relaxed at the beginning of the contact time,25 all proton magnetization spin locked in the rotating frame decays at the same rate (T ph), and the contact time is sufficient to allow complete cross polarization (at least 5 times the longest TCp)26 Except when relative peak intensities are constant and appear to be correct, single contact time measurements should be avoided. Instead, 13C spectra and relaxation times should be measured and complete magnetization curves analyzed. 

S NMR spectroscopy is potentially an adequate method for both qualitative and quantitative analysis of mixtures of organosulphur compounds. Kosugi62 has reported the 33S spectra of mixtures of 1- and 2-naphthalenesulphonates and of 1,5- and 2,6-naphthalene disulphonates at concentrations of approximately 0.15 M in D20. In both cases, (NH4)2S04 was used as an internal standard to determine chemical shifts and for quantitative analysis. At a magnetic field of 5.9 T, the 33S spectra of the two mixtures show two quite sharp and well-resolved resonances, and the results reported indicate that the quantitative analysis of these isomers is possible with a relative error of less than 10%. 

Nishioka, Watanabe, Abe, and Sono (48) carried out an extensive study of the Grignard reagent catalyzed polymerization of methyl methacrylate in toluene with respect to tactidty of the resulting polymers. The tactidty of the polymer was determined quantitatively by nuclear magnetic resonance analysis. It was found that the stereo-regularity depended on the nature of the R group of the Grignard... 

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