Determination of albumin adducts of (+)-anti-benzo[a]pyrene-diol-epoxide using an HPLC column switching technique for sample preparation and GC-NCI-MS for the final detection

The ultimate carcinogen of BaP, the 7,8-diol-9,10-epoxide, which is formed in mammal;an metabolism can bind to macromolecules such as DNA or proteins. Protein adducts of carcinogens are used as surrogate markers for DNA-adduc ts, which are responsible far tumor initiation. Reaction with the plasma protein albumin occurs via ester formation with as partic or glutamic acid residues. We have developed a method for the determ ination of BPDE-abumin adducts. Hydrolysis of the adducts gives rise to ben zo[a]pyrene-r-7,t-8,t-9,c-10-tetrahydrotetrol which was enriched and purifi ed by HPLC with a column switching technique. The final detection was perfo rmed with GC-MS and negative chemical ionization (NCI). We found detectable amounts of BT I-1 in 28 of 69 (41%) blood samples from volunteers, not occ upationally exposed to PAH. Adduct levels ranged from below the detection l imit (0.01 fmol/mg) to 0.25 fmol/mg albumin. The mean value was 0.026+/-0.0 47 fmol/mg albumin. Smokers (n-23) had significantly elevated adduct concen trations (0.045+/-0.060 fmol/mg) compared to nonsmokers (n-24; 0.015+/-0.04 0 fmol/mg) and passive smokers (n-22; 0.016+/-0.029 fmol/mg).