Electron Transfer Dissociation and Synchrotron UV Photodissociation of Trapped Sodiated Ions Produced From Polyacrylates by Electrospray Ionization.

Rationale: Poly (acrylates)s can be distinguished from one another by the nature of their side chains. From model poly (acrylates)s, the purpose of this work was to evaluate the contribution of alternative activation techniques to the collisional activation, based on ion-ion and ion-photon interactions.

Methods: Sodiated poly (acrylate)s produced by electrospray were isolated in an ion trap and then submitted to interactions with fluoranthene anions (by electron transfer dissociation) or with UV photons (from a synchrotron UV source, 16 eV) to induce gas-phase decomposition. The resulting fragmentation pathways were investigated and compared with collision-induced dissociation (CID). Ion mobility spectrometry was coupled to UV photoactivation for some isobaric species.

Results: Electron capture from fluoranthene anions or electron loss under synchrotron UV irradiation induced dissociation that differs from CID. A coupling of ion mobility with UV photoactivation allowed the fragmentation of two isobaric species separately.

Conclusions: The decomposition products (ETD, UV-PD) stand out from those coming from classical low-energy CID by inducing specific side-chain fragmentations. These particular fragmentations make them easy to identify.