FIGURE 6.

LC-MS/MS detection of sulfated metabolites (M1 and M2) of the B[a]P-7,8-catechol formed by recombinant SULT1A3 (A) and by A549 (B), H358 (C), and HBEC-KT cells (D) at 24 h. B[a]P-7,8-dione (2 μm, 0.2% DMSO) in HBSS buffer were incubated with lung cells and collected at 0 and 24 h, respectively. The culture media were extracted with ethyl acetate. The organic phases were dried under vacuum and redissolved in methanol. B[a]P-7,8-catechol sulfates were analyzed with LC-MS/MS in the negative ion mode by monitoring the reaction transition m/z 363→283 ([M-H]⁻ → [M-H-SO₃]⁻). The peak M1 had the same retention time and mass transition as authentic 8-hydroxy-B[a]P-7-O-sulfate.