Differentiation of diastereoisomeric terpenoid alcohols by electron impact and negative ion chemical ionization associated with collision-induced dissociation. A fourier transform ion cyclotron resonance study

Electron impact ionization-collision-induced dissociation (EI-CID) and negative ion chemical ionization-collision-induced dissociation (NICI-CID) experiments have been performed on the molecular or quasi-molecular ions (M^+· or M - H]^?) of series of terpenoid alcohols, using a Fourier transform ion cyclotron resonance spectrometer. These terpenes belong to the p-menthane family and bear a hydroxyl group in various positions relative to the isopropyl or isopropenyl substituent (positional or stereochemical isomers). In the case of positional isomers, different CID spectra were always obtained. Within a given diastereoisomeric series, stereochemical differences were also observed in both NICI-CID and EI-CID experiments.