RESUMO
A comprehensive account of spatially resolved solid-state MAS NMR of 13C is given. A device generating field gradients rotating synchronously with the magic angle spinner is described. Spatial resolution and sensitivity are compared for phase and frequency encoding of spatial information. The suppression of spinning sidebands is demonstrated for both cases. Prior knowledge about the involved materials can be used for the reduction of data from spatially resolved spectra to map chemical structure. Indirect detection via 13C NMR gives access to the information about mobility from proton-wideline spectra. Two-dimensional solid-state spectroscopy with spatial resolution is demonstrated for a rotor synchronized MAS experiment which resolves molecular order as a function of space. By comparison of different experiments the factors affecting the spatial resolution are investigated.
Assuntos
Espectroscopia de Ressonância Magnética/métodos , Isótopos de Carbono , Polímeros/química , PrótonsRESUMO
The local alcohol concentration in the human brain was determined in 10 cases using MR spectroscopic imaging. Therefore 7 subjects with an average blood alcohol concentration of 0.8/000 were examined after oral intake of alcoholic beverages. Varying alcohol concentration was found intracranially which was recorded spectroscopically w.r.t. time. Relatively high ethanol concentrations were determined in the cerebellum as well as in the ventricular system. Contrary to this, lower concentrations were found in the regions of grey and white matter.