High-resolution NMR "chromatography" using a liquids spectrometer.
NMR spectroscopy is an excellent tool for the structural analysis of pure compounds. However, for mixtures it performs poorly because of overlapping signals. Diffusion can be used to separate compounds of widely differing molecular weight but the amount of separation is usually insufficient. Addition of a solid medium, analogous to the stationary phase in chromatography, can preferentially slow the diffusion of some components of a mixture permitting separation in the diffusion dimension. However, this would usually require a solid-state NMR spectrometer otherwise the signals would be too broad. Susceptibility matching the solvent to the solid medium yields a spectrum with narrow signals allowing the measurement of a DOSY spectrum with enhanced separation in the diffusion dimension.
Hoffman
Roy E
RE
Department of Organic Chemistry, E Safra Campus, Givat Ram, The Hebrew University of Jerusalem, Jerusalem, Israel. royh63@gmail.com
Arzuan
Hilla
H
Pemberton
Chava
C
Aserin
Abraham
A
Garti
Nissim
N
D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012822:Silicon Dioxide / Q000737:chemistry*; D012996:Solutions; D013048:Specimen Handling / Q000379:methods*
D012996:Solutions; D012822:Silicon Dioxide