Scientific Publications by FDA Staff
Magn Reson Chem 1998 Jun;36(6):403-6
A proposed standard sample for nuclear Overhauser effect measurements
Bain AD, Mazzola EP, Page SW
A standard sample for the measurement of proton¿proton nuclear Overhauser effects (NOE) is proposed. 1,5-Dichloro-2,4-dimethoxybenzene (DCDMB) shows an essentially full (50%) enhancement of the proton H-3 when the protons of the flanking methoxyl groups are saturated. The molecule is appropriate as a standard for the following reasons. The molecule is stable and easily synthesized. All the lines in the spectrum appear as singlets, so selective population transfer effects cannot obscure the NOE. The proton at position 6 provides a monitor of other relaxation mechanisms that would reduce the NOE. The NOE was verified by two complementary experiments. One is the standard technique of measuring the intensity with and without irradiation. A second method, based on spin¿lattice relaxation rate experiments, provides unbiased data and gives an statistical estimate of the errors. Within experimental error, the NOE for DCDMB is 50%.
|Category: Journal Article|
|Includes FDA Authors from Scientific Area(s): Food|
|Entry Created: 2012-12-28|