Oxidation of 2,5,2′,5′-TCB by CYP2A6 (A and B), CYP2A24 (C and D), CYP2A26 (E and F), CYP2A13 (G and H), and CYP2A23 (I and J) on analysis with LC-MS/MS using a CORTECS C18 column (A, C, E, G, and I) and RP-amide column (B, D, F, H, and J). P450 and 2,5,2′,5′-TCB concentrations used were 0.1 and 50 µM, respectively, and incubation time was 60 minutes.