Nuclear magnetic resonance spectroscopy high-resolution

Fluorescence in UV radiation is a frequently used method for detection of TLC spots, e.g. of Tinuvin 326 [42]. The fluorescence emitted by optical brighteners under UV light on a thin-layer plate has been utilised as a means of analysing these compounds [42]. On the whole, the use of fluorescence detection in poly-mer/additive analysis of extracts is certainly not overwhelming. Applied fluorescence has been described in a monograph [156]. 

In principle, measurement of the phosphorescence characteristics of samples obtained after extraction of polymers with organic solvents may also yield useful information regarding the nature and concentration of the additives present. Parker and Hatchard [157] have examined the possibilities of phosphorescence measurements for V-phenyl-2-naphthylamine. Although it should be possible to determine various analytes simultaneously by correct choice of ex and em wavelengths and phosphorescence decay, no pertinent reports are available. Phosphorescence finds limited application for the direct determination of additives in polymers (without prior extraction). 

4 HIGH-RESOLUTION NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY 

Principles and Characteristics No other physicochemical method applied to liquids has come close to 

Radiofrequency spectroscopy (NMR) was introduced in 1946 [158,159]. The development of the NMR method over the last 30 years has been characterised by evolution in magnet design and cryotechnology, the introduction of computer-based operating systems and pulsed Fourier transform methods, which permit the performance of new types of experiment that control production, acquisition and processing of the experimental data. New pulse sequences, double-resonance techniques and gradient spectroscopy allow different experiments and have opened up the area of multidimensional NMR and NMRI. 

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Brown, J.K. and W.R. Ladner Jr (1960), Distribution in coallike materials by high-resolution nuclear magnetic resonance spectroscopy . Fuel, Vol. 39, p. 87. 

J. W. Emsley, j. Feeney and L. H. Sutcliffe, High Resolution Nuclear Magnetic Resonance Spectroscopy, Vols. 1 and 2, Pergamon Press, Oxford, 1966, Chap. 11, Fluorine-19, pp. 871-968. 

Duarte, A. Barros, P. S. Belton, R. Righelato, M. Spraul, E. Humpfer, A. M. Gil 2002, (High-resolution nuclear magnetic resonance spectroscopy and multivariate analysis for the characterisation of beer),/. Agric. Food Chem. 50, 2475-2481. 

High-resolution Nuclear Magnetic Resonance Spectroscopy... 

Emsley,J.W.,Feeney, J., Sutcliffe, L. H. High Resolution Nuclear Magnetic Resonance Spectroscopy, Vol. 1, Chaps. 3 and 5. New York Pergamon Press 1965. 

High-resolution nuclear magnetic resonance spectroscopy, especially 13C NMR, is a powerful tool for analysis of copolymer microstructure [Bailey and Henrichs, 1978 Bovey, 1972 Cheng, 1995, 1997a Randall, 1977, 1989 Randall and Ruff, 1988], The predicted sequence length distributions have been verihed in a number of comonomer systems. Copolymer microstructure also gives an alternate method for evaluation of monomer reactivity ratios [Randall, 1977]. The method follows that described in Sec. 8-16 for stereochemical microstructure. For example, for the terminal model, the mathematical equations from Sec. 8-16a-2 apply except that Pmm, Pmr, Pm and Prr are replaced by p, pi2, p2j, and p22. 

Bovey.F.A. and Tiers,G.V.D. The High Resolution Nuclear Magnetic Resonance Spectroscopy of Polymers. Vol. 3, pp. 139—195. 

High resolution nuclear magnetic resonance spectroscopy of molecules yields, in favorable situations, separate resonances for nuclei in nonequiva-... 

High-resolution nuclear magnetic resonance spectroscopy also has the potential for rapid sample throughput and could expand the range of metabolites readily detectable. The instrumentation is expensive and interpretation requires considerable... 

Structure Determination of Polypropylene Oxide by High Resolution Nuclear Magnetic Resonance Spectroscopy... 

Oguni.N., Komoda,T., Nomura,M., Tani,H. Studies on microstructure of polystyrene oxide and its a-deuterated derivatives with high resolution nuclear magnetic resonance spectroscopy (in preparation). 

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