The efficacy of a newly developed gas chromatography-negative ion chemical ionization-mass spectrometry-selected ion monitoring (GC-NICI-MS- SIM) assay for measuring globin adducts of benzo[a]pyrene (B[a]P) and chrysene diol epoxides in humans was evaluated. In this pilot study, smokers and nonsmokers were selected as exposed and nonexposed groups. Using [2H12]r-7,t-8,9,c-10-tetrahydroxy-7,8,9,10-tetrahydrobenzo[a]pyrene ([2H12]trans, anti-B[a]P-tetraol) as an internal standard, B[a]P-tetraols released from globin after hydrolysis and derivatization were quantified by GC-NICI-MS-SIM. Levels of trans-1,2-dihydroxy-3,4-epoxy-1,2,3,4- tetrahydrochrysene (chrysene-DE)-globin adducts were estimated by assuming that the recovery and the MS response of the perdeuterated B[a]P-tetraol internal standard reflected the recovery and MS response of chrysene tetraols. The assay was found to be reproducible and sensitive enough to detect both analytes in all samples. The mean levels of B[a]P-tetraols released from the corresponding benzo[a]pyrene diol epoxide (BPDE) globin adducts in smokers were significantly higher than those in nonsmokers, i.e., 2.6 ± 0.6 SE fmol/mg globin (ranging from 1.2 to 7.8 fmol/mg globin) in smokers and 0.97 ± 0.05 SE fmol/mg globin (ranging from 0.7 to 1.3 fmol/mg globin) in nonsmokers (P < 0.01). Interestingly, estimated levels of chrysene-DE-globin adducts in the same subjects were about two orders of magnitude higher than those of the globin adducts of BPDE. The mean of the chrysene-DE adducts in smokers was estimated to be 310 ± 30 SE fmol/mg globin (ranging from 190 to 460 fmol/mg globin) and that in nonsmokers was 250 ± 25 SE fmol/mg globin (ranging from 110 to 380 fmol/mg). Although the estimated mean of chrysene-DE adducts with globin in smokers appeared to be about 25% higher than in nonsmokers, the difference was not significant (P = 0.06). The results of this study demonstrate the feasibility of the GC-NICI- MS-SIM method for measurement of BPDE globin adducts in humans.
|Original language||English (US)|
|Number of pages||7|
|Journal||Cancer Epidemiology Biomarkers and Prevention|
|State||Published - 1997|