Electrospray characterization of perrhenate systems.

The electrospray negative ion mode (ESI-) mass spectrometry study of freshly prepared perrhenate in the ammonium and alkali metal (Na and K) solutions has been detailed. The cone voltage dependency of the negative ion abundance clearly indicates that the collision-activated dissociation (CAD) process in the cone-to-skimmer region is the source for both linear and non-linear cone voltage dependencies. The model also highlights that the [ReO2]- and [ReO3]- ions observed in the ESI- spectra are not present in the bulk, but are due to a dissociative collision, which strips a single oxygen atom from their precursor ions, namely [ReO3]- and [ReO4]- , respectively.