Combining energy-dependent electrospray ionisation with tandem mass spectrometry for the analysis of inorganic compounds

The recently developed technique of energy‐dependent electrospray ionisation mass spectrometry (EDESI‐MS) has been implemented on a triple quadrupole mass spectrometer such that fragmentation occurs in the collision cell rather than at the skimmer cone. This modification enables a superior two‐dimensional map of the collision voltage versus mass‐to‐charge ratio to be generated, providing unambiguous peak assignments. This latest enhancement to the technique is referred to as energy‐dependent electrospray ionisation tandem mass spectrometry (EDESI‐MS/MS). In the present work the technique has been applied to investigate the sequential removal of ligands from the inorganic mixed‐metal anionic cluster compound [Ru5CoC(CO)16]−, which serves to illustrate the advantages of this approach