Determination of methyltin and butyltin compounds in waters of the Antwerp harbor

Ionic methyltin and butyltin compounds were determined in dockwater of the harbour of Antwerp (Belgium) in order to evaluate the emission and distribution of organotin species discharged during dry dock activities. Speciation analysis was performed by gas chromatography-quartz furnace atomic absorption spectrometry (GC-QFAAS) and gas chromatography with atomic emission detection (GC-AED) after enrichment by extraction of the analytes as the corresponding diethyldithiocarbamate (DDTC) complexes into pentane and pentylation of the extracted analytes with Grignard reagent. Concentrations of dimethyltin (DMT), monomethyltin (MMT), tributyltin (TBT), dibutyltin (DBT) and monobutyltin (MBT), varied between 0.74 and 5; 0.88 and 10; 1.83 and 443; 1.45 and 120; 1.08 and 38 ng.l-1 at various locations and sampling times in the harbour docks of Antwerp, the highest concentrations of TBT being found near a vessel repair facility. In one of the harbour docks, the concentrations of butyltins increased from May until August due to the discharge of tributyltin in hosing-down water and the launching of freshly painted sea-going vessels