Cone voltage and collision cell collision-induced dissociation study of triphenylethylenes of pharmaceutical interest.

Fragmentations of three triphenylethylene compounds (toremifene and its two metabolites) with different functional side-chain groups (alcohol, acid and amine) were studied. The compounds were dissociated by collision-induced dissociation (CID) in the interface region of an electrospray ionization source (ESI(+)) and in the collision cell of a triple quadrupole mass spectrometer. Fragmentation pathways for these molecules are proposed, based on accurate mass measurements of in-source fragment ions and MS/MS experiments using product and precursor ion scanning. The side-chain functional groups were found to strongly affect the fragmentations of the molecular ions. The fragmentation pathways of the protonated molecule and sodium ion adduct were quite similar, but the subsequent stabilities of certain common fragments were surprisingly different.