DETERMINATION OF TRIBUTYLTIN, DIBUTYLTIN AND TOTAL TIN IN THE GALICIAESTUARIES BY HPLC-ETAAS

Butyltin compounds were extracted and preconcentrated from sea water s amples with a liquid-liquid extraction procedure using 0.03% tropolone in chloroform the extracts were evaporated until dry and redissolved in methanol. The determination of these compounds was performed with h igh performance liquid chromatography (HPLC) directly coupled with ele ctrothermal atomic absorption spectrometry (ETAAS). The sensitivity ob tained with this procedure was 31 ng l(-1) and 28 ng l(-1), for TBT an d DBT, respectively. Total tin was extracted and preconcentrated with a solution of 0.5% oxine in isobutylmethylketone (IBMK) and the extrac ts were directly subjected to ETAAS. The sensitivity obtained for tota l tin was 0.9 mg l(-1). These two procedures were applied to the deter mination of butyltin compounds and total tin in sea water samples of e stuaries in Galicia (Northwest of Spain).