Determination of butyltin species in water and sediment by solid-phase microextraction-gas chromatography-flame ionization detection

A procedure for determination of tetraethyltin (TeET) and tetrabutyltin (Te BT) in water by solid-phase microextraction (SPME) using the headspace appr oach has been developed. The method has been adapted for the simultaneous d etermination of mono-, di- and tributyltin species (MBT, DBT and TBT) after derivatization with sodium tetraethylborate in water and sediment samples. The analytical procedures were optimized with respect to stirring conditio ns, extraction time and extraction temperature. The pH and the amount of de rivatizing reagent were also considered in derivatization reaction procedur es. The analysis was carried out using gas chromatography equipped with fla me ionization detection. The detection limits obtained for TeET and TeBT, i n equilibrium conditions (room temperature fbr TeET and 40 degrees C for Te BT) were 28 and 20 ng/l (as Sn), respectively. The detection limit for buty ltin species in water, which was limited by signals which are non-specific for the tin compounds and the sensitivity of the FID system, was found ca. 1 mu g/l (as Sn). The SPME method was validated for analysis of sediments b y analyzing the certified reference material PACS-2 finding a good agreemen t with the certified values. (C) 2000 Elsevier Science B.V. All rights rese rved.