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

Abstract

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.

Fragmentation reactions of protonated peptides containing glutamine or glutamic acid

“…It has been established43–45 that the average energy imparted to the decomposing ion increases as the field in this interface region increases. Indeed, recent work46–49 has shown that, by varying this field in steps, energy‐resolved CID mass spectra are obtained which are comparable to those obtained in variable low‐energy CID in quadrupole collision cells. The results of these CID experiments are presented in the following either as breakdown graphs expressing the percent of total ion signal as a function of the cone voltage, a measure of the field in the interface region, or as CID mass spectra.…”

Fragmentation of protonated dipeptides containing arginine. Effect of activation method

“…It has been clearly established [21][22][23][24][25] that CID in this fashion produces CID mass spectra similar to those produced by low-energy CID in quadrupole collision cells. MS 2 and MS 3 experiments were also carried out using an electrospray/ quadrupole/time-of-flight mass spectrometer (QStar; MDS SCIEX, Concord, Canada).…”

Amide bond cleavage in deprotonated tripeptides: a newly discovered pathway to ″b2 ions

“…It is well known19,20 that CID can be achieved in this region, so‐called cone‐voltage CID, and it has been clearly established21–23 that the average energy imparted to the decomposing ions increases as the field in the interface region increases. Indeed, recent work24–27 has shown that, by varying this field in steps, energy‐resolved mass spectra28–30 comparable to those obtained in variable low‐energy CID in quadrupole cells can be obtained. The results of these cone‐voltage CID experiments are presented in the following either as CID mass spectra at a set cone voltage or as breakdown graphs expressing the percent of total ion abundance as a function of the cone voltage, a measure of the field in the interface region.…”