TOXICOKINETICS AND BIOTRANSFORMATION OF PENTACHLOROPHENOL IN THE SEA-URCHIN (STRONGYLOCENTROTUS-PURPURATUS)

1. The toxicokinetics and biotransformation of pentachlorophenol (PCP) were determined in the purple sea urchin (Strongylocentrotus purpuratus). 2. In a static chamber, urchins (n=9) were individually exposed to 50 mu g/l of [U-C-14]PCP for 24 h to determine bioconcentration and the absorption rate constant (K-a), elimination rate constant (K-e), and elimination half-life (t(1/2)). Determination was by direct quantitation of radioactivity in the exposure water. 3. After exposure, urchins were placed in a flow-through chamber for 24 h to allow depuration of retained residues, which were identified by hplc and quantified by lsc. The K-a and K-e, calculated using a simplified model, were 0.12+/-0.06 h and 0.43+/-0.22 h, respectively, whilst the 24-h total concentration factor was 316.3+/-209.7, and the t(1/2) was 1.6+/-0.8 h. 4. Whereas urchins depurated 40.6% of retained residues, only a small amount of PCP was excreted unchanged (17.0%), as the more polar conjugates pentachlorophenyl-beta-D-glucoside (72.4%) and pentachlorophenylsulphate (10.6%) were also formed.