Neutral loss and precursor ion scan tandem mass spectrometry for study of activated benzopyrene-DNA adducts

Methodology for detection of activated benzo[a] pyrene (B[a] P)-nucleoside adducts by liquid chromatography-tandem mass spectrometry is reported. Adducts of B[a]P-dihydrodiol epoxide (B[a]PDE) with guanosine and adenosine have been detected for the first time by use of precursor ion scan and neutral loss scan. B[a]P was then activated by use of UV irradiation and some of the products obtained have been identified by taking advantage of the information obtained for B[a]PDE. Photoactivation has also been carried out in the presence of hydrogen peroxide; this resulted in a higher yield of products with increased production of BaP diones. The reactivity of these compounds toward nucleosides has been tested. The proposed method was successfully used for detection of one stable guanosine-B[a]P dione adduct.