STUDIES ON THE RETENTION OF INDIVIDUAL POLYCHLORINATED DIBENZOFURANS (PCDFS) IN THE LIVER OF DIFFERENT SPECIES

A mixture of nineteen individual PCDF congeners (of which 17 were analyzed) was given as a single oral dose (0.1 μg of each congener/kg body weight) to rats, guinea pigs and hamsters. Postadministration levels of PCDFs in the liver were determined for days 1, 5, 10, 30 and 90. The analytical technique applied for the determination included clean-up of the liver tissues using basic and acidic silica, alox and Carbopak C columns and HRGC-HRMS analyses. This procedure resulted in a method detection level below 1 ppt (0.1 - 1 ppt depending on sample or congener). The fates of the 17 PCDFs were found to be highly species and congener dependent. In rats and hamsters, almost only 2,3,7,8-substituted congeners were detected in liver at this detection level at either timepoint. In contrast, the guinea pigs retained most of the congeners administrated. Elimination of the retained congeners followed first order kinetics with elimination half-lives of 2 - 85 days. © 1990.