Disposition and biotransformation of pentachlorophenol in the red abalone (Haliotis rufescens).

1. The disposition and biotransformation of pentachlorophenol (PCP) in the red abalone (Haliotis rufescens) have been determined. 2. In a flow-through system, three abalones were exposed to 1.2 mg/l of [U-14C]PCP for 5 h to determine bioconcentration and tissue distribution. Retained residues were quantified from radioactivity, while excreted residues were identified and quantified by h.p.l.c. and determination of radioactivity. 3. The 5-h total concentration factor ranged from 16.0 to 21.5; individual tissue concentrations ranged from 133.4 nmol/g in gill to 17.5 nmol/g in gonad. Due to its large size, the foot muscle received the largest amount of total retained residue (47.4%). 4. During a 13-h recovery period the abalones depurated 72.2% of retained residues; however, residue concentration in gonad increased over 100%. PCP was primarily excreted unchanged (89.3%), but small amounts of pentachloro-beta-D-glucoside (7.9%), pentachloroanisole (1.3%), pentachlorophenylsulphate (0.9%), and tetrachloro-p-hydroquinone (0.6%) were also formed.