ENHANCED PHOTOACTIVATED LUMINESCENCE OF SELECTED POLYCHLORINATED BIPHENYL CONGENERS AND AROCLOR MIXTURES

Fluorescence studies of selected polychlorinated biphenyl (PCB) congen ers and Aroclor mixtures were conducted using enhanced photoactivated luminescence. Diphenylamine (DPA) was used as a photoactivator. DPA re acts with PCBs to form a fluorescent photoproduct under UV activation. The sensitivities of fluorescence detection using three different sol id substrates were compared. Background studies of the substrates and DPA blanks were also conducted to determine the substrate with the bes t detection characteristics for enhanced photoactivated fluorescence. It was found that the Envi disk with a glass-fiber mesh and C-18-modif ied silica provides more analyte access for fluorescence detection, th ereby providing best sensitivity. By comparison of the fluorescence fr om pure PCB congener-DPA complexes, the more coplanar congeners exhibi ted a red shift in excitation and emission as compared with the outho- substituted nonplanar congeners. These studies may prove useful in det ermining trends relating fluorescence intensity and toxicity factors. (C) 1997 Academic Press.