TABLE 1

Optimized mass spectrometric parameters for the analysis of 4-oxo-carbazeran, carbazeran, 8-oxo-O6-benzylguanine, O6-benzylguanine, and tolbutamide (internal standard) by UPLC-MS/MS

Chemicalm/z Transition Declustering Potential Entrance Potential Collision Energy Collision Cell Exit Potential Dwell Time Curtain Gas Collision-Activated Dissociation Gas Ion Spray Voltage Ion Source Temperature Ion Source Gas 1Ion Source Gas 2
m/zVVVVmspsipsiV°Cpsipsi
Carbazeran 4-oxidation assay
 4-Oxo-carbazeran377.2→288.01006.3023.05.40200301240005505050
 Carbazeran361.3→272.213010.0045.014.00200301240005505050
 Tolbutamide (internal standard)271.1→91.1676.0045.06.50200301240005505050
O6-Benzylguanine 8-oxidation assay
 8-Oxo-O6-benzylguanine258.0→91.192.68.0027.08.5320020940004004040
O6-Benzylguanine241.9→91.273.510.5035.07.0020020940004004040
 Tolbutamide (internal standard)271.1→172.176.98.1917.05.5020020940004004040