SPME-GCMS for speciation of butyltin compounds in marine environment

A method for determination of butyltin species using SPNE-GCMS in environmental samples has been standardised. The ionic butyltin compounds present in seawater and sediment samples were converted to their hydride forms using sodium tetrahydroborate (NaBH4). These derivatized compounds were extracted using headspace solid phase microextraction (SPME) technique. A polydimethylsiloxane (PDMS) coated fibre (100 mum film thickness) was used to extract butyltin hydrides. The extracted analytes were then transferred to a GC-MS system for desorption, separation and quantification. The detection limits obtained with SPME-GCMS for monobutyl, dibutyl and tributyl tin compounds for different matrices varied between 0.1 and 0.5 picogram. The optimized method was applied for the speciation study of butyltin compounds in seawater and sediment from different part of the Thane Creek. The levels of butyl tin compounds in sediments of Thane Creek varied from 32-178 ng/g while in Creek water it varied from 2-35 ng/l.