Nuclear magnetic resonance spectrometry applications

Nomenclature of heterocycles, 20, 175 Nuclear magnetic resonance spectroscopy, application to indoles, IS, 277 Nucleic acids, mass spectrometry of, 39, 79 Nucleophiles, bifunctional, cyclisations and ring transformations on reaction of azines with, 43, 301... 

Improvements in column technology, detector sensitivity and the development of new detection systems, have made possible the routine separation of picomole quantities of nucleic acid components in complex physiological matrices. The very sensitivity of most LC systems, however, which is invaluable in the analysis of biological samples, is often the limiting factor because of inadequate or ambiguous identification methods. Although tremendous advances have been made in the on-line combination of HPLC with spectroscopic techniques [e.g., mass spectrometry, Fourier transform infrared (FT/IR), nuclear magnetic resonance], their application has not become routine in most biochemical and biomedical laboratories. 

T. Renukappa, G. Roos, I. Klaiber, B. Vogler, and W. Kraus, Application of high-performance liquid chromatography coupled to nuclear magnetic resonance spectrometry, mass spectrometry and bioassay for the determination of active saponins from Bacopa Monniera Wettst.,7. Chromatogr. A 847 (1999), 109-116. 

Following the introduction presented in Chapter 1, this book discusses the application and use of specific analytical techniques (mass, infrared, and nuclear magnetic resonance spectrometry, chromatography, and capillary electrophoresis) in the combinatorial chemistry field (Chapters 2-6). It also discusses how to make sense of the vast amounts of data generated (Chapter 7), details how the actual libraries of compounds produced are utilized (Chapter 8), and lists some of the vast commercial resources available to researchers in the field of combinatorial chemistry (Chapter 9). 

Malinowski ER (1978) Theory of error for target factor analysis with applications to mass spectrometry and nuclear magnetic resonance spectrometry. Anal Chim Acta 103 359-354 Malinowski ER (1991) Factor Analysis in Chemistry. John Wiley, New York,... 

The hydrocarbon ("oil") fraction of a coal pyrolysis tar prepared by open column liquid chromatography (LC) was separated into 16 subfractions by a second LC procedure. Low voltage mass spectrometry (MS), infrared spectroscopy (IR), and proton (PMR) as well as carbon-13 nuclear magnetic resonance spectrometry (CMR) were performed on the first 13 subfractions. Computerized multivariate analysis procedures such as factor analysis followed by canonical correlation techniques were used to extract the overlapping information from the analytical data. Subsequent evaluation of the integrated analytical data revealed chemical information which could not have been obtained readily from the individual spectroscopic techniques. The approach described is generally applicable to multisource analytical data on pyrolysis oils and other complex mixtures. 

In addition, a number of advanced analytical techniques, such as low temperature luminescence spectroscopy, tandem mass spectrometry (MS/MS), Fourier-Transform IR-spectroscopy and nuclear magnetic resonance spectrometry have been successfully applied to PAH analysis. For instance, low temperature luminescence spectrometry, sometimes in combination with laser excitation, was used for the analysis of PAH in various matrices without prior separation, which is attractive especially for screening or finger-printing purposes (10, 73). However, a wider application for routine analysis is at present inhibited by the limited availability of the required equipment. The same remark applies to tandem mass spectrometry, FT-IR spectroscopy and NMR. All three techniques, however, are increasingly used for the detection and identification of novel PAH species and derivatives and efforts are continuing towards coupling IR and NMR as detectors to GC and HPLC (74) respectively. 

See also-. Extraction Solvent Extraction Principles. Gas Chromatography Mass Spectrometry High-Temperature Techniques. Liquid Chromatography Normal Phase Reversed Phase Liquid Chromatography-Mass Spectrometry. Nuclear Magnetic Resonance Spectroscopy - Applicable Elements Nitrogen-15. 

See also Atomic Absorption Spectrometry Principles and Instrumentation. Chiroptical Analysis. Chromatography Overview Principles. Clinical Analysis Glucose. Enzymes Enzyme-Based Electrodes. Food and Nutritional Analysis Overview. Infrared Spectroscopy Overview. Mass Spectrometry Overview. Nuclear Magnetic Resonance Spectroscopy Overview. Nuclear Magnetic Resonance Spectroscopy Applications Food. Optical Spectroscopy Detection Devices. Sampling Theory. Spectrophotometry Overview. Sweeteners. X-Ray Absorption and Diffraction Overview. 

See also Gas Chromatography Overview. Lipids Overview Fatty Acids Poiar Lipids. Mass Spectrometry Overview. Nuclear Magnetic Resonance Spectroscopy-Applicable Elements Phosphorus-31. 

See also Extraction Solid-Phase Extraction. Food and Nutritional Analysis Oils and Fats Fruits and Fruit Products. Lab-on-a-Chip Technologies. Liquid Chromatography Liquid Chromatography-Nuclear Magnetic Resonance Spectrometry. Nuclear Magnetic Resonance Spectroscopy Oven/iew Principles Instrumentation. Nuclear Magnetic Resonance Spectroscopy Applications Food. Nuclear Magnetic Resonance Spectroscopy Techniques Solid-State. Peptides. Radiochemical Methods Radiotracers Pharmaceutical Applications. 

See also Bioassays Overview. Drug Metabolism Metabolite Isolation and Identification. Infrared Spectroscopy Ovenriew. Liquid Chromatography Liquid Chromatography-Nuclear Magnetic Resonance Spectrometry Pharmaceutical Applications. Mass Spectrometry ... 

See also Atomic Absorption Spectrometry Principles and Instrumentation. Atomic Emission Spectrometry Inductively Coupled Plasma. Cosmetics and Toiletries. Derivatization of Analytes. Electrophoresis Is-otachophoresls. Environmental Analysis. Enzymes Overview. Extraction Supercritical Fluid Extraction Solid-Phase Extraction Solid-Phase Microextraction. Ion Exchange Ion Chromatography Applications. Liquid Chromatography Reversed Phase Liquid Chromatography-Mass Spectrometry. Nuclear Magnetic Resonance Spectroscopy - Applicable Elements Carbon-13 Phosphorus-31. Perfumes. 

Albert, K. Schlotterbeck, G. Tseng, L.-H. Braumann, U. Application of on-line capillary high-performance liquid chromatography-nuclear magnetic resonance spectrometry coupling for the analysis of vitamin A derivatives. 

One has seen that the number of individual components in a hydrocarbon cut increases rapidly with its boiling point. It is thereby out of the question to resolve such a cut to its individual components instead of the analysis by family given by mass spectrometry, one may prefer a distribution by type of carbon. This can be done by infrared absorption spectrometry which also has other applications in the petroleum industry. Another distribution is possible which describes a cut in tei ns of a set of structural patterns using nuclear magnetic resonance of hydrogen (or carbon) this can thus describe the average molecule in the fraction under study. 

Very little in the way of advances has occurred since 1971 in the applications of ultraviolet or infrared spectroscopy to the analysis of fluonnated organic compounds Therefore, only gas-liquid chromatography, liquid chromatography, mass spectrometry, and electron scattering for chemical analysis (ESCA) are discussed The application of nuclear magnetic resonance (NMR) spectroscopy to the analysis of fluonnated organic compounds is the subject of another section of this chapter... 

Other methods of identification include the customary preparation of derivatives, comparisons with authentic substances whenever possible, and periodate oxidation. Lately, the application of nuclear magnetic resonance spectroscopy has provided an elegant approach to the elucidation of structures and stereochemistry of various deoxy sugars (18). Microcell techniques can provide a spectrum on 5-6 mg. of sample. The practicing chemist is frequently confronted with the problem of having on hand a few milligrams of a product whose structure is unknown. It is especially in such instances that a full appreciation of the functions of mass spectrometry can be developed. 

Mass spectrometry, infrared spectroscopy, and nuclear magnetic resonance spectroscopy are techniques of structure determination applicable to all organic molecules. In addition to these three generally useful methods, there s a fourth—ultraviolet (UV) spectroscopy—that is applicable only to conjugated systems. UV is less commonly used than the other three spectroscopic techniques because of the specialized information it gives, so we ll mention it only briefly. 

Several modem analytical instruments are powerful tools for the characterisation of end groups. Molecular spectroscopic techniques are commonly employed for this purpose. Nuclear magnetic resonance (NMR) spectroscopy, Fourier transform infrared (FTIR) spectroscopy and mass spectrometry (MS), often in combination, can be used to elucidate the end group structures for many polymer systems more traditional chemical methods, such as titration, are still in wide use, but employed more for specific applications, for example, determining acid end group levels. Nowadays, NMR spectroscopy is usually the first technique employed, providing the polymer system is soluble in organic solvents, as quantification of the levels of... 

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. 

---