RESUMO
Accurate duplicate bioconcentration factors were determined for tetrachlorobenzyltoluenes (TCBTs). This is the first study that quantifies bioconcentration factors for single TCBT isomers. A continuous flow uptake experiment was performed during 21 days with the zebra mussel (Dreissena polymorpha) as a test organism. Bioconcentration factors (BCFs) and rate constants were derived by an iterative integration method. With this method BCFs and rate constants can be derived from experimental data of a bio-concentration test, even if the concentration in the water is not constant and steady state has not been reached. Mean log BCF values of TCBTs ranged from 4.43 +/- 0.05 to 5.19 +/- 0.15 liter.kg-1 on a wet weight basis. The experimental log BCF values were compared with log BCF values of TCBTs, calculated according to linear and polynomial relationships between log BCF and log Kow.
Assuntos
Compostos Benzidrílicos/toxicidade , Bivalves/metabolismo , Hidrocarbonetos Clorados/toxicidade , Bifenilos Policlorados/metabolismo , Poluentes Químicos da Água/análise , Animais , Compostos Benzidrílicos/metabolismo , Cromatografia Gasosa , Hidrocarbonetos Clorados/metabolismo , Cinética , Bifenilos Policlorados/análise , Estereoisomerismo , Relação Estrutura-AtividadeRESUMO
Preliminary bioconcentration factors (BCFs) were determined of six tetrachlorobenzyltoluenes (TCBTs) in guppies (Poecilia reticulata). BCFs and rate constants were derived by an iterative integration method. With this method BCFs and rate constants can be derived from experimental data of a bioconcentration test, even if the concentration in the water is not constant and steady state has not been reached. Log BCF values of TCBTs in guppies ranged from 1.67 to 2.68 L.kg-1 on a wet weight basis. These values are much lower than the reported log BCF values of TCBTs in zebra mussels (Dreissena polymorpha) determined with the same method. Biotransformation of TCBTs in guppies as an explanation for the higher log BCF values in zebramussel is discussed.
