GC-APLI-MS as a powerful tool for the analysis of BaP-tetraol in human urine

Richter-Brockmann S, Dettbarn G, Jessel S, John A, Seidel A, Achten C

Abstract

For the first time gas chromatography (GC) coupled to atmospheric pressure laser ionization-mass spectrometry(APLI-MS) has been applied to the analysis of trans-anti-benzo[a]pyrene-tetraol (BaP-tetraol) formed from antibenzo[a]pyrene diolepoxide (BPDE), the ultimate carcinogen of benzo[a]pyrene. This tetraol is considered to bean ideal urinary biomarker for polycyclic aromatic hydrocarbon (PAH) exposure as it reflects internal bodyburden and potentially adverse health effects.Optimization of the derivatization and the instrumental set-up led to an instrumental LOD of 0.5 fg, an improvementof the lowest instrumental LOD reported in literature of 6.4 fg by a factor of 10. The optimizedprocedure includes derivatization of hydroxyl groups using methyl iodide and cool on-column injection toprevent degradation of the analyte. First measurements of urine samples demonstrate that the method is capableof detecting BaP-tetraol in human urine collected from both smokers and non-smokers. Although results ofanalysis indicate a certain underestimation compared with literature data, this method can be expected to serveas an excellent method for the analysis of the biomarker BaP-tetraol in the future if an adequate internal standardsuch as 13C-labeled BaP-tetraol is applied.