Nuclear magnetic resonance high-performance liquid

RS Plumb, J Ayrton, GJ Dear, BC Sweatman, IM Ismail. The use of preparative high performance liquid chromatography with tandem mass spectrometric directed fraction collection for the isolation and characterisation of drug metabolites in urine by nuclear magnetic resonance spectroscopy and liquid chromatography/sequential mass spectrometry. Rapid Commun Mass Spectrom 13 (10) 845-854,1999. 

Plumb, R.S. Ayrton, J. Dear, G.J. Sweatman, B.C. Ismail, I.M. The Use of Preparative High Performance Liquid Chromatography with Tandem Mass Spectrometric Directed Fraction Collection for the Isolation and Characterisation of Drug Metabolites in Urine by Nuclear Magnetic Resonance Spectroscopy and Liquid Chromatography/Sequential Mass Spectrometry, Rapid Commun. Mass Spectrom. 13, 845-854 (1999). 

Although saponification was found to be unnecessary for the separation and quantification of carotenoids from leafy vegetables by high performance liquid chromatography (HPLC) or open column chromatography (OCC), saponification is usually employed to clean the extract when subsequent purification steps are required such as for nuclear magnetic resonance (NMR) spectroscopy and production of standards from natural sources. 

D2O = deutered water. HPLC = high performance liquid chromatography. IS = internal standard. MeOH = methanol. MS = mass spectrometry. NMR = nuclear magnetic resonance. PDA = photodiode array detector. TEA = triethylamine. MTBE = methyl tert-butyl ether. 

Strohschein, S., Pursch, M., and Albert, K., Hyphenation of high performance liquid chromatography with nuclear magnetic resonance spectroscopy for the characterization of (3-carotene isomers employing a Cjq stationary phase, J. Pharm. Biom. Anal., 21, 669, 1999. 

Hentschel, P. et ah. Structure elucidation of deoxylutein 11 isomers by on-line capillary high performance liquid chromatography- H nuclear magnetic resonance spectroscopy, J. Chromatogr. A, 1112, 285, 2006. 

M.E. Lacey, Z. J. Tan, A. G. Webb, J. V. Sweedler 2001, (Union of capillary high-performance liquid chromatography and microcoil nuclear magnetic resonance spectroscopy applied to the separation and identification of terpenoids), J. Chromatogr. A 922(1-2), 139. 

FID = flame ionization detection GC = gas chromatography HPLC = high performance liquid chromatography ITMS = ion trap mass spectrometry MS = mass spectrometry PNMR = proton nuclear magnetic resonance TLC = thin-layer chromatography... 

Because carotenoids are light- and oxygen-sensitive, a closed-loop hyphenated technique such as the on-line coupling of high performance liquid chromatography (HPLC) together with nuclear magnetic resonance (NMR) spectroscopy can be used for the artifact-free structural determination of the different isomers. 

In the case of heterogeneous polymers the experimental methods need to be refined. In order to analyze those polymers it is necessary to determine a set of functions / (M), which describe the distribution for each kind of heterogeneity i This could be the mass distributions of the blocks in a diblock copolymer. The standard SEC methods fail here and one needs to refine the method, e.g., by performing liquid chromatography at the critical point of adsorption [59] or combine SEC with methods, which are, for instance, sensitive to the chemical structure, e.g., high-pressure liquid chromatography (HPLC), infrared (IR), or nuclear magnetic resonance spectroscopy (NMR) [57],... 

In addition to the above prescriptions, many other quantities such as solution phase ionization potentials (IPs) [15], nuclear magnetic resonance (NMR) chemical shifts and IR absorption frequencies [16-18], charge decompositions [19], lowest unoccupied molecular orbital (LUMO) energies [20-23], IPs [24], redox potentials [25], high-performance liquid chromatography (HPLC) [26], solid-state syntheses [27], Ke values [28], isoelectrophilic windows [29], and the harmonic oscillator models of the aromaticity (HOMA) index [30], have been proposed in the literature to understand the electrophilic and nucleophilic characteristics of chemical systems. 

Meyer, C., Skogsberg, U., Welsch, N., and Albert, K., Nuclear magnetic resonance and high-performance liquid chromatographic evaluation of polymer-based stationary phases immobilized on silica. Anal. Bioanal. Chem., 382, 679, 2005. 

High-Performance Liquid Chromatography-Nuclear Magnetic Resonance... 24... 

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