Fluorescence behaviour of polychlorinated dibenzofurans in organized molecular systems. Analytical applications

The fluorescent characteristics of several typical polychlorinated dibenzofurans (PCDF) in different anionic, cationic and neutral surfactants, as well as in the presence of alpha-cyclodextrin, beta-cyclodextrin and n-hexane, are reported. The excitation and emission maxima of the different PCDF in the various media are summarized. The presence of the surfactant polyoxyethylene(10)lauryl ether (POLE) produced the greatest fluorescence enhancement for PCDF, except in the case of 2,4,6-PCDF. Given the environmental importance of 2,3,7,8-tetrachlorodibenzofuran, an analytical study of this PCDF in the presence of the POLE surfactant was used to establish a sensitive spectrofluorimetric method for its determination. Optimization studies were carried out to determine optimum variables such as POLE concentration, percentage of organic solvent and temperature, and the effect of possible interferences from other PCDF, polychlorinated dibenzodioxins and polychlorinated biphenyls. The fluorescence of 2,3,7,8-PCDF was measured at 336 nm (excitation at 304 nm). Calibration curves were obtained from solutions prepared in the same optimized conditions. The detection limit for tetrachlorodibenzofuran was 1.3 ng per ml. This method was applied to 2,3,7,8-TCDF analysis in seawater samples. There are 37 references.