FLUORESCENCE SPECTROSCOPIC STUDIES ON THE IDENTIFICATION AND QUANTIFICATION OF 7H-DIBENZO[C,G]CARBAZOLE AND DIBENZ[A,J]ACRIDINE METABOLITES

Fluorescence spectroscopic techniques were developed and employed in t he identification and quantitation of the metabolites of the carcinoge nic pollutants 7H-dibenzo[c,g]carbazole (DBC) and dibenz[aj]acridine ( DBA) after HPLC separation. Metabolites formed in vitro with 3-methylc holanthrene (3-MC)-induced Sprague-Dawley rat liver microsomal prepara tions were used as the model for this research. The fluorescence spect ra of the three major DBC metabolites matched those of the synthetic s tandards, 1-OH-, 3-OH- and 5-OH-DBC, respectively. Similarly, the fluo rescence spectra of the four major DBA metabolites matched those of th e synthetic standards, 1,2-diol-, 3,4-diol-, 5,6-diol- and 5,6-epoxide -DBA, respectively. Synchronous fluorescence spectroscopy (SFS) has be en especially helpful for the identification of these metabolites sinc e it produces a single peak for each compound. Regression equations of the SFS peak areas versus concentrations of the synthetic standards w ere used to calculate quantities of the microsomal metabolites from th e SFS peak areas of the metabolites. These values were comparable with those quantities calculated from radioactivity measurements. The use of HPLC combined with SFS is a convenient and sensitive nonradiometric method which can be used to identify and quantify DBC and DBA metabol ites.