GAS-CHROMATOGRAPHIC MASS-SPECTROMETRIC DETERMINATION OF BENZO[A]PYRENE AND CHRYSENE DIOL EPOXIDE GLOBIN ADDUCTS IN HUMANS

The efficacy of a newly developed gas chromatography-negative ion chem ical 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, s mokers and nonsmokers were selected as exposed and nonexposed groups, Using -10-tetrahydroxy-7,8,9,10-tetrahydrobenzo[a]pyrene ([H-2(12)]tra ns,anti-B[a]P-tetraol) as an internal standard, B[a]P-tetraols release d from globin after hydrolysis and derivatization were quantified by G C-NICI-MS-SIM. Levels of 1,2-dihydroxy-3,4-epoxy-1,2,3,4-tetrahydrochr ysene (chrysene-DE)-globin adducts were estimated by assuming that the recovery and the MS response of the perdeuterated B[a]P-tetraol inter nal standard reflected the recovery and MS response of chrysene tetrao ls. The assay was found to be reproducible and sensitive enough to det ect both analytes in all samples, The mean levels of B[a]P-tetraols re leased from the corresponding benzo[a]pyrene diol epoxide (BPDE) globi n adducts in smokers were significantly higher than those in nonsmoker s, i.e., 2.6 +/- 0.6 SE fmol/mg globin (ranging from 1.2 to 7.8 fmol/m g 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, e stimated levels of chrysene-DE-globin adducts in the same subjects wer e about two orders of magnitude higher than those of the globin adduct s of BPDE. The mean of the chrysene-DE adducts in smokers was estimate d 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 (rangi ng from 110 to 380 fmol/mg), Although the estimated mean of chrysene-D E adducts with globin in smokers appeared to be about 25% higher than in nonsmokers, the difference was not significant (P = 0.06), The resu lts of this study demonstrate the feasibility of the GC-NICI-MS-SIM me thod for measurement of BPDE globin adducts in humans.