Study of the accumulation of tributyltin and triphenyltin compounds and their main metabolites in the sea bass, Dicentrachus labrax, under laboratory conditions

Accumulation of two triorganotins, tributyltin (TBT) and triphenyltin (TPhT), has been studied by exposing the sea bass, Dicentrachus labrax, to different concentrations of both compounds, under controlled laboratory conditions. D. labrax juvenile fish were acclimatized in a laboratory and isolated to four groups. One group was used as control (first group), while the other three were exposed, during 28 days, in tanks with seawater containing simultaneously 2.5 μg/l TBT and 2.5 μg/l (second group), 5 μg/l TBT and 5 μg/l (third group) and 15 μg/l TBT and 15 μg/l (fourth group), respectively. The higher exposure dose caused mortality to all animals after 48 h. In the other two groups, quantitative analysis of TBT and TPhT was carried out, weekly, on the target organs (muscle and liver). Also, the main metabolites of TBT, monobutyltin (MBT) and dibutyltin (DBT), and TPhT, monophenyltin (MPhT) and diphenyltin (DPhT) were monitored. Gas chromatography (GC) coupled to mass spectrometry in tandem (MS/MS) mode was used for their identification. The results of analysis of TBT and TPhT showed that D. labrax accumulated the compounds from the first week, although the levels depended on medium concentration exposure. Liver was found to accumulate higher concentrations of TBT and TPhT than muscle.