Accumulation and depuration of chlorinated phenolics in the freshwater mussel (Anodonta anatina L.).

Uptake from ambient water and the depuration of five chlorinated phenolics, two chloroguaiacols (3,4,5-tri- and tetrachloroguaiacol), and three chlorophenols (2,4,6-tri-, 2,3,4,6-tetra-, and pentachlorophenol) were studied in the duck mussel (Anodonta anatina). Groups of animals were exposed at four acclimiation temperatures (3, 8, 13, 18 degrees C) to four chlorophenolic concentrations (total 6-56 micrograms/liter). The depuration was monitored for 72 hr. For the analysis of individual chlorophenolics by the GC/ECD technique, the soft tissue of mussels was homogenized, spiked with internal standard, acetylated, and extracted with n-hexane. The bioconcentration factors (BCF) (concn. in animal wet wt./concn. in water) were determined for mussel soft tissue. The highest BCF was found for pentachlorophenol (81-461) and the lowest for trichlorophenol (14-125). Neither water temperature nor exposure concentration affected the BCFs. The compounds studied were depurated rapidly and their depuration half-lives (T1/2) in soft tissue were generally less than 24 hr.