SIDE-BAND ANALYSIS IN DOR NMR-SPECTRA .2. REAL FINITE INNER-ROTOR SPEED

DOR (double orientation rotation) solid-state NMR technique is analyzed specifically in the case where numerous (> 4) sidebands are observed on the spectrum. In this case, a rough spectrum analysis leads to the false observation of several impurity species. The total ''visible'' intensity is smaller than the real one. This may lead to an apparent relative concentration change when several species with very different quadrupole interactions coexist in the sample. Contrary to the MAS technique, the correct analysis of DOR spectra with sidebands very often necessitates the simultaneous introduction of CSA and quadrupole interactions.