POLAR FARMS OF BENZO[A]PYRENE MAY BE UBIQUITOUS IN THE ENVIRONMENT

Previously, we reported that polar polycyclic aromatic compounds (pola r PAC) can be detected by first oxidizing them with KO2/O-2 and then d etecting the carboxylic acid products, after pentafluorobenzylation, b y gas chromatography electron capture mass spectrometry (Allam et at. Anal. Chem. 1992, 65, 1723-1727). For example, we used the method in t he cited study to detect a benzo[a]pyrene tetrahydrotetraol hydrolysis product derived from benzo[a]pyrene-exposed lymphocytes after isolati on of the DNA. However,the method was limited in its sensitivity by th e presence of an interfering, analyte-like peak in the final mass chro matograms. Now, the results of our current work strong ly suggest that the contamination leading to the unwanted peak is ubiquitous in the u rban environment. Results from the analysis of a standard reference sa mple of urban particulate matter (SRM 1649) yielded a level of 10 ng o f contaminant in a 5-mg sample (2 mu g/g). The concentration of this p olar contaminant is comparable to the certified value for benzo[a]pyre ne of 14.5 ng (2.9 mu g/g). Furthermore, our mass spectral data show e vidence for the presence of many other polar PAC in the sample. These observations add to the concern raised by related environmental health studies focused on the potential impact of airborne polar PAC on huma n health.