Pulsed field gradients NMR

Group 2 Radiotracer pulsed field gradient NMR measurements (PFG NMR) ... 

Advances in experimental techniques, including pulsed-field gradient NMR, and theoretical methods, including volume averaging, macrotransport, and variational methods, that may lead to the resolution of a number of the fundamental issues in gel electrophoresis and to improvements in the practical application of electrotransport in polymeric media... 

Johnson et al. [186] measured diffusion of fluorescein-labeled macromolecules in agarose gels. Their data agreed well with Eq. (85), which combined the hydrodynamic effects with the steric hindrance factors. Gibbs and Johnson [131] measured diffusion of proteins and smaller molecules in polyacrylamide gels using pulsed-field gradient NMR methods and found their data to fit the stretched exponential form... 

Brown, W Stilbs, P Lindstrom, T, Self-Diffusion of Small Molecules in Cellulose Gels using FT-Pulsed Field Gradient NMR, Journal of Applied Polymer Science 29, 823,1984. Brownstein, KR Tarr, CE, Importance of Classical Diffusion in NMR Studies of Water in Biological Cells, Physical Review A 19, 2446, 1979. 

Gibbs, SJ Johnson, CS, Pulsed Field Gradient NMR Study of Probe Motion in Polyacrylamide Gels, Macromolecules 24, 6110, 1991. 

Hinton, DP Johnson, CS, Diffusion Coefficients, Electrophoretic Mobilities, and Morphologies of Charged Phospholipid Vesicles by Pulsed Field Gradient NMR and Electron Microscopy, Journal of Colloid and Interface Science 173, 364, 1995. 

U. Tallarek, D. van Dusschoten, H. Van As, E. Bayer, G. Guiochon 1998, (Study of transport phenomena in chromatographic columns by pulsed field gradient NMR),/. Phys. Chem. B 102, 3486. 

G. J. W. Goudappel, J. P. M. van Duyn-hoven, M. M. W. Mooren 2001, (Measurement of oil droplet size distributions in food oil/water emulsions by time domain pulsed field gradient NMR), /. Colloid Interface Sci. 239, 535. 

Pulsed field gradient NMR has become a standard method for measurement of diffusion rates. Stilbs [272] and others have exploited in particular the FT version for the study of mixtures. An added advantage of PFG-NMR is that it can be employed to simplify complex NMR spectra. This simplification is achieved by attenuation of resonances based on the differential diffusion properties of components present in the mixture. 

Zhang O, Kay LE, Olivier JP, Forman-Kay JD. Backbone 11 and 15N resonance assignments of the N-terminal SFI3 domain of drk in folded and unfolded states using enhanced sensitivity pulsed field gradient NMR techniques. J Biol NMR 1994 4 845-858. 

SJ Gibbs, EN Lightfoot, TW Root. Protein diffusion in porous gel filtration chromatography media studied by pulsed field gradient NMR spectroscopy. J Phys Chem 96 7458-7462, 1992. 

Pulsed field gradient NMR (PFG-NMR) spectroscopy has been successfully used for probing interactions in several research fields.44-53 The method was developed by Stejskal and Tanner more than 40 years ago54 and allows the measurement of self-diffusion coefficient, D, which is defined as the diffusion coefficient in absence of chemical potential gradient. 

In addition to Ti and T2, which reflect the rotational motion of water, NMR can also be used to measure the translational motion of water. If an additional, relatively small (compared to B0), steady magnetic field gradient is incorporated into a pulsed NMR experimental setup, a translational diffusion coefficient (D, m2/s) can be measured (called pulsed field gradient NMR). 

Dixon, A. M. and Larive, C. K. (1997). Modified pulsed-field gradient NMR experiments for improved selectivity in the measurement of diffusion coefficients in complex mixtures application to the analysis of the Suwannee River fulvic acid, Anal. Chem., 69, 2122-2128. 

Force field, diffusion in zeolites, 42 6 Forcing transform, pulsed-field gradient NMR, 39 392-394 Formaldehyde... 

Water self-diffusion coefficients (Dh o) have been determined by pulse field gradient NMR for Nation (Nil/) , BPSH, and SPEEKK and have been shown to increase with increasing acid and water content. At high water contents, the values for PEMs approach the corresponding value for pure water. This is due to the increase in volume fraction of free water. At low water content, however. Nation exhibits greater Dnp values than either BPSH or SPEEKK. In corranon with the observations for EOD, this has been attributed to the smaller channels in aromatic-based polymers, leading to a considerably lower dielectric constant for the water in the channels. 

Dong, L., Kim, Y. S., Wang, F, Hickner, M., Glass, T. E. and McGrath, J. E. 2003. Self-diffusion of water in sulfonated poly(arylene ether sulfone) copolymers by pulse field gradient NMR. Polymer Preprints 44 355. 

Ye, G., Hayden, C. A. and Coward, G. R. 2007. Proton dynamics of nation and Nafion/Si02 composites by solid state NMR and pulse field gradient NMR. Macromolecules 40 1529-1537. 

Lateral diffusion of phospholipids in model membranes at ambient pressure has been studied over the years by a variety of techniques including fluorescence recovery after photobleaching (FRAP), spin-label ESR, pulse field gradient NMR (PFG-NMR), quasielastic neutron scattering (QENS), excimer fluorescence and others.In general, the values reported for the lateral diffusion coefficient (D) range from 10 to 10 cm /s in the... 

Three analytical expressions for the spin-echo intensity as a function of the gradient in a pulsed field gradient NMR experiment for spins diffusing in a sphere with reflecting walls are reinvestigated. It is found that none of the published formulas are completely correct. By numerical comparisons the correct formula is found. 

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