DETERMINATION OF BUTYLTIN COMPOUNDS IN SEDIMENTS USING AN IMPROVED AQUEOUS ETHYLATION METHOD

We have determined tributyltin and dibutyltin species in various envir onmental sediment samples (marine, harbour and river sediment) using t he in situ aqueous ethylation-gas chromatography-atomic absorption spe ctrometry method subsequent to extraction by methanol containing 0.5M HCl. The present technique provides a significantly lower detection li mit than previous methods, so that tributyltin can for the first time be measured in some of the samples. Thus, the method described is well suited for the determination of tributyltin and dibutyltin compounds in sediments with low levels of butyltin species (e.g., Main River, 1. 7 ng of tributyltin as Sn/g dry sediment).