LETHAL BODY BURDENS OF POLAR NARCOTICS - CHLOROPHENOLS

The goal of the present study was to measure in fathead minnow (Pimeph ales promelas) the lethal body burden (LBB) of three chlorophenols tha t are known as polar narcotic chemicals. The LBBs of the chlorophenols were compared to LBBs of nonpolar narcotic chemicals to consider if t he two classes of narcotic chemicals differ on a body burden level. Th e LBB of the most acidic chlorophenol was measured at two different le vels of pH exposure to determine the influence of the degree of ioniza tion on the magnitude of the LBB. Both n-octanol/water partition coeff icients and n-hexane/water partition coefficients of the chlorophenols were determined at different pH levels to consider the influence of i onization on the partition coefficient and to determine the importance of a polar group in the organic phase on the partitioning behaviour. Partitioning to n-octanol and n-hexane was used as input in a model to simulate the equilibrium partitioning between hydrophobic and nonhydr ophobic and target and nontarget compartments in the fish.