Energy‐dependent collision‐induced dissociation study of buprenorphine and its synthetic precursors

The collision‐induced dissociation (CID) of protonated buprenorphine ([M+H] + ) and four related compounds was studied by electrospray quadrupole/time‐of‐flight mass spectrometry (ESI‐QTOF MS). The fragmentation pathways were investigated by using energy‐dependent CID and pseudo‐MS 3 (in‐source CID combined with tandem mass spectrometry (MS/MS)) methods. The first steps of the fragmentation are the parallel losses of the substituents from the non‐aromatic ring moieties. Depending on the applied collision energies, a large number of further fragment ions arising from the cross‐ring cleavages of the core‐ring structure were observed. Based on the experimental results, a generalized fragmentation scheme was developed for the five buprenorphine derivatives highlighting the differences for the alternatively substituted compounds. The collision‐energy‐dependent fragmentation profile of buprenorphine is visualized in a two‐dimensional plot to aid its fingerprint identification. Copyright © 2010 John Wiley & Sons, Ltd.