Determination of butyltin compounds in river sediment samples by gas chromatography–atomic absorption spectrometry following in situ derivatization with sodium tetraethylborate

Abstract

A method for the determination of butyltin compounds in river sediments is described. The method involves in situ ethylation of organotins by sodium tetraethylborate in aqueous buffered solution, simultaneous purging and trapping of ethylation derivatives and detection by atomic absorption spectrometry. The absolute detection limits (3σ of baseline noise) for mono-, di- and tributyltin are 0.08, 0.34 and 0.11 ng of tin, respectively. The concentration detection limits achieved are 9, 38 and 12 ng of tin per gram of sediment (dry mass), respectively. The technique has been successfully applied to the determination of tributyltin and dibutyltin in a spiked river sediment. For the accurate measurement of butyltin compounds in river sediment, a method based on extracting sediment with various volumes of solvent is used.