Fundamental Studies of Fentanyl Protomers and their Gas-Phase Structure

Protomers, or prototropic isomers, are protonation site isomers than can be resolved using ion mobility spectrometry. Dating back to their first report by Karpas et al. in 1990, decades of literature have studied their fundamental properties. Recently, our group and others have identified the presence of protomers for many fentanyl analogues, owing to their multiple…

Chemical Reactions and Noncovalent Complexes as Ion Mobility ‘Shift Reagents’

Where the resolving power of IM-MS techniques is insufficient to differentiate challenging isomers, various chemical approaches have been used to alter their mobility with the goal of better separations. We are primarily focused on simple, fast, and inexpensive reactions targeting common steroid functional groups. Thus far, we have published on reactions with ozone, simple carbonyls…