Toxicokinetics and biotransformation of pentachlorophenol in the sea urchin (Strongylocentrotus purpuratus)

Abstract

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 μg/1 of [U-¹⁴C]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 Isc. 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-β-D-glucoside (72.4%) and pentachlorophenylsulphate (10.6%) were also formed.