Letter: Differentiation Of Isomeric Mercapturic Acid Pathway Metabolites Of Benzo[A]Pyrene

Isomeric forms of the mercapturic acid pathway metabolites of benzo[a]pyrene (EP) tan be differentiated by positive-ion electrospray collision-induced dissociation (CID) mass spectrometry at the nanogram level, The metabolite (+)-r-7,t-8-dihydroxy-t-9,10-epoxy-7,8,9,10-tetrahydrobenzo[a]pyrene (BPDE), conjugated at position 10 (bay region) with cysteine, fragments to give characteristic ions at m/z 303 corresponding to a BP-triol cation, these ions are not observed in the CID spectra of BPDEs conjugated at position 7 (non-bay region).