Nuclear magnetic resonance flowing liquids

C. A. Fyfe, M. Cocivera, S. W. H. Damji 1975, (High resolution nuclear magnetic resonance studies of chemical reactions using flowing liquids. Investigation of the kinetic and thermodynamic intermediates formed by the attack of meth-oxide ion on l-X-3,5-dinitrobenzenes), J. Am. Chem. Soc. 97, 5707. 

J. F. Haw, T. E. Glass, D. W. Hausler, E. Motell, and H. C. Dorn, Direct coupling of a liquid chromatograph to a continuous flow hydrogen nuclear magnetic resonance detector for analysis of petroleum and synthetic fuels. And. Chem. 52 (1980), 1135-1140. 

Broad-line nuclear magnetic resonance has been used to study melting in stearic acid and a mesomorphic crystalline to waxy) phase transition in lithium stearate. Extensive motion, liquidlike, though less extensive than that in an isotropic free-flowing liquid, takes place within the system below the melting point of stearic acid or the crystalline to waxy phase transition of lithium stearate. The amount of liquid-like character, as measured by the intensity of a narrow component in the NMR spectrum relative to the total intensity of the whole spectrum, depends on the presence of impurities in the system and even more significantly on whether and how many times the sample has been melted. 

Zhernovoi, A.I. and Latyslev, G.D. (1965) Nuclear Magnetic Resonance in Flowing Liquids, Consultants Bureau, New York. 

The most successful temperature dependence for the viscous flow [1,2], viscoelastic response [1], dielectric dispersion [3-5], nuclear magnetic resonance response [6-8] and dynamic light scattering [9-10] of polymers and supercooled liquids with various chemical stmctures is the Williams, Landel, and Perry (WLF) equation [11,12]... 

LC-nuclear magnetic resonance (NMR) One information-rich spectral technique that is more suited to the liquid mobile phase of HPLC than to the vapor phase of GC is NMR. LC-NMR has been implemented, but it has significant limitations. To obtain interpretable spectra of unknowns, concentrations in the measurement cell must be higher than with other detectors. The cell must be smaller than the usual NMR tube, so for any but the very highest concentrations of analytes, FT-NMR acquisition is preferred, with each eluted peak being retained in the measmement cell by a stopped-fiow procedme similar to that employed to increase sensitivity in GC-IR (Section 12.8.2). Expensive deuterated mobile-phase solvents are required for proton NMR, which mandates the use of low mobile-phase volume flow columns narrow-bore or even capillary HPLC. LC-NMR is expensive to implement and only just becoming available from commercial vendors at this time. 

---