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 an d distribution of organotin species discharged during dry dock activit ies. Speciation analysis was performed by gas chromatography-quartz fu rnace atomic absorption spectrometry (GC-QFAAS) and gas chromatography with atomic emission detection (GC-AED) after enrichment by extractio n of the analytes as the corresponding diethyldithiocarbamate (DDTC) c omplexes into pentane and pentylation of the extracted analytes with G rignard reagent. Concentrations of dimethyltin (DMT), monomethyltin (M MT), tributyltin (TBT), dibutyltin (DBT) and monobutyltin (MBT), varie d between 0.74 and 5; 0.88 and 10; 1.83 and 443; 1.45 and 120; 1.08 an d 38 ng.l-1 at various locations and sampling times in the harbour doc ks of Antwerp, the highest concentrations of TBT being found near a ve ssel repair facility. In one of the harbour docks, the concentrations of butyltins increased from May until August due to the discharge of t ributyltin in hosing-down water and the launching of freshly painted s ea-going vessels.