Nuclear magnetic resonance spectroscopy 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). 

Infrared spectroscopy has been used for quantitatively measuring the amounts of 1,2-, 3,4-, cis-1,4-, and trans-1,4-polymers in the polymerization of 1,3-dienes its use for analysis of isotactic and syndiotactic polymer structures is very limited [Coleman et al., 1978 Tosi and Ciampelli, 1973]. Nuclear magnetic resonance spectroscopy is the most powerful tool for detecting both types of stereoisomerism in polymers. High-resolution proton NMR and especially 13C NMR allow one to obtain considerable detail about the sequence distribution of stereoisomeric units within the polymer chain [Bovey, 1972, 1982 Bovey and Mirau, 1996 Tonelli, 1989 Zambelli and Gatti, 1978],... 

Cody, G. D., Alexander, C. M. O., and Tera, F. (2002). Sohd-state ( H and C) nuclear magnetic resonance spectroscopy of insoluble organic reside in the Muchison meterorite A self-consistent quantitative analysis. Geochim. Cosmochim. Acta 66(10), 1851—1865. 

The structure and identity of such compounds that are of practical relevance as com-plexing agents may be elucidated unequivocally by both one-dimensional and two-dimensional nuclear magnetic resonance spectroscopy of the isotopes H-l, C-13, and P-31. Sufficiently high concentrations also render possible their quantitative analysis [87-91]. However, because of the low sensitivity, especially of the phosphorus nucleus, problems are encountered with the limits of detection in practical applications. 

McKenzie, J.M. and Koch, K.R. Rapid analysis of major components and potential authentication of South African olive oils by quantitative C nuclear magnetic resonance spectroscopy. South African Journal of Science, 100, 349-354. 2004. 

Infrared spectroscopy has been extensively used in both qualitative and quantitative pharmaceutical analysis [1-3], This technique is important for the evaluation of the raw materials used in production, the active ingredients and the excipients (the inert ingredients in a drug formulation, e.g. lactose powder, hydroxypropyl cellulose capsules, etc.). Although nuclear magnetic resonance spectroscopy and mass spectrometry are widely used in the pharmaceutical industry for the identification of drug substances, infrared spectroscopy can provide valuable additional structural information, such as the presence of certain functional groups. 

Dawson BA (1991) The use of nuclear magnetic resonance spectroscopy for detection and quantitation of abused drugs. In Gough TA (ed.) The Analysis of Drugs of Abuse. Chichester Wiley. 

R41 N. W. Lutz and P. J. Cozzone, Metabolic Profiling in Multiple Sclerosis and Other Disorders by Quantitative Analysis of Cerebrospinal Fluid Using Nuclear Magnetic Resonance Spectroscopy , Curr. Pharm. Biotechnol., 2011, 12, 1016. 

Many techniques for the analysis of anthocyanins have been used for almost a century and are still of importance, along with considerable advances in technologies such as mass spectroscopy (MS) and nuclear magnetic resonance (NMR). This section summarizes the analytical procedures for quantitative and qualitative analyses of anthocyanins, including classical and modem techniques. 

Perhaps the most revolutionary development has been the application of on-line mass spectroscopic detection for compositional analysis. Polymer composition can be inferred from column retention time or from viscometric and other indirect detection methods, but mass spectroscopy has reduced much of the ambiguity associated with that process. Quantitation of end groups and of co-polymer composition can now be accomplished directly through mass spectroscopy. Mass spectroscopy is particularly well suited as an on-line GPC technique, since common GPC solvents interfere with other on-line detectors, including UV-VIS absorbance, nuclear magnetic resonance and infrared spectroscopic detectors. By contrast, common GPC solvents are readily adaptable to mass spectroscopic interfaces. No detection technique offers a combination of universality of analyte detection, specificity of information, and ease of use comparable to that of mass spectroscopy. 

Modern spectroscopy plays an important role in pharmaceutical analysis. Historically, spectroscopic techniques such as infrared (IR), nuclear magnetic resonance (NMR), and mass spectrometry (MS) were used primarily for characterization of drug substances and structure elucidation of synthetic impurities and degradation products. Because of the limitation in specificity (spectral and chemical interference) and sensitivity, spectroscopy alone has assumed a much less important role than chromatographic techniques in quantitative analytical applications. However, spectroscopy offers the significant advantages of simple sample preparation and expeditious operation. 

Several methods are available in the literature for the measurement of aliphatic amines in biological samples [28]. Problems with specificity and separation and cumbersome derivatisation and/or extraction procedures have limited the use of these techniques on a larger scale in clinical practice. The lack of a simple analytical method may have led to an underestimation of the incidence of the fish odour syndrome. For diagnosing the syndrome, an analytical technique should be used that is able to simultaneously and quantitatively measure TMA and its N-oxide in the complex matrix of human urine. Two such methods are currently available for this purpose proton nuclear magnetic resonance (NMR) spectroscopy and head-space gas analysis with gas chromatography or direct mass spectrometry (see below). 

For simple poly(a-olefins) of practical importance, the chain stereostructure can be quantitatively determined at least at the stereotriad level [1], Longer configurational sequences can be observed by nuclear magnetic resonance, particularly using larger magnetic fields or 13C NMR spectroscopy or both. The chemical shifts due to CH3,CH2 and CH carbons are widely spaced. It is mainly the chemical shift of the pendant CH3 group carbon that is utilised for sequential analysis. 

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