Direct detection of solanesol in tobacco by proton and carbon-13 magic angle spinning NMR

Abstract

his advice in preparing the manuscript. I also thank Neis David Bemander for his help in procuring and preparing the samples for assay.

Magnetic resonance imaging characterization of intact smoked cigarettes

“…Once again, this process can be conveniently monitored by NMR. Because the molecular motion of waxes is much more rapid (longer T 2 ) than for the polysaccharides or other semi-rigid substances in tobacco, 1 H NMR with magic-angle-spinning can be employed to obtain high-resolution spectra of these components without interference from the rigid cell wall components [2]. Recently this method has been called ''highresolution magic-angle-spinning NMR'' (HR-MAS NMR).…”

“…Tobacco leaf constituents with high molecular mobility have been observed directly in shredded tobacco by 1 H MAS NMR and by 13 C MAS NMR (i.e. without cross-polarization) [2]. To obtain 1 H MRI maps of these same substances in the tobacco filler inside a cigarette, spin-echo methods are generally adequate.…”

A Comparison of NMR Spectra Obtained for Solid-Phase-Synthesis Resins Using Conventional High-Resolution, Magic-Angle-Spinning, and High-Resolution Magic-Angle-Spinning Probes

“…This is in contrast to MAS which completely eliminates the effects of all discontinuities both regions now becomes important since each region potentially around and within the sample-the ability to eliminate this has a different susceptibility, which can affect the resonance effect becomes increasingly important at higher field frequencies of nearby nuclei and cause a distribution of strengths and with higher frequency nuclei (like 1 H) where chemical shifts (which will appear as an increase in the the line broadening becomes more severe and the chemical-NMR linewidths). This magnetic-susceptibility line broadshift dispersion is small (26). In solid-state NMR, MAS is ening (also called susceptibility-limited resolution) of hetconventionally used only to remove chemical-shift anisoterogeneous samples has previously been shown to compliropy effects or to average dipolar couplings; the magneticcate spectroscopic assignments in cellular tissues and other susceptibility effects are typically disregarded.…”

“…however, or completely suspended in the solvent to form a slurry, many lines should narrow due to an increase in the The magnitude of the susceptibility shift is determined by the composition of each region and hence its net volume molecular motions that allow the chemical shifts to average to their isotropic values. While the relatively rigid polymer susceptibility (c v ), the geometry of each region (if nonspherical), its orientation relative to the applied field, and the support would still be expected to generate broad NMR resonances, the attached organic moieties should have sufficient shifts from surrounding regions (25)(26)(27). The magneticsusceptibility effects arising from each of these microscopic molecular motion to generate narrow linewidths.…”

“…(31), compartmentalized liquid samples (32,33), memWhile this is a critical consideration in building modern branes (34), seeds (35), leaves (26), and emulsions (36), high-resolution probes, it is currently only a distant secondhave shown that the magnetic-susceptibility broadening vanary consideration in constructing MAS probes used for solidishes when the sample is spun about the magic angle (54.7Њ state studies, where high spinning speeds, variable temperarelative to the static magnetic field). MAS rates of 1-2 ture ranges, and high-power-handling issues dominate.…”