ANALYSIS OF THE DNA-DAMAGE INDUCED BY PHENYL GLYCIDYL ETHER USING CAPILLARY-ZONE-ELECTROPHORESIS ELECTROSPRAY MASS-SPECTROMETRY

The in vitro adduct formation between phenyl glycidyl ether (PGE) and calf thymus DNA was investigated. Agarose slab gel electrophoresis of DNA incubated with PGE revealed that nearly all high-molecular-weight species were degraded after 10 h of incubation. After DNA precipitatio n the reaction products present in the supernatant were subjected to a solid-phase extraction on a polystyrene divinylbenzene copolymer, ena bling analysis on capillary zone electrophoresis (CZE), using sample s tacking. These reaction products were mainly produced during the first 10 h of incubation, indicating that these products result from the DN A degradation. On the other hand, analysis of the adducts present in t he enzymatic digest of the DNA pellet revealed that these adducts were formed only after 10 h of incubation. The reaction products present i n the DNA supernatant were identified by on-line coupling of CZE to el ectrospray tandem mass spectrometry. Three major reaction products res ulted from phosphate alkylation, as proven by the analysis of the corr esponding low-energy CAD product ion mass spectra. This phosphate alky lation results in phosphotriesters which readily hydrolyze, resulting in DNA strand breaks. (C) 1998 Academic Press.