SPECIATION OF BUTYLTIN COMPOUNDS IN SEDIMENTS USING GAS-CHROMATOGRAPHY INTERFACED WITH QUARTZ FURNACE ATOMIC-ABSORPTION SPECTROMETRY

A method is presented for the determination of tri- and dibutyltin in sediments by gas chromatography-quartz furnace atomic absorption spectrometry. The compounds are released from the matrix by the action of acetic acid and extracted into hexane after formation of an extractable complex with diethyldithiocarbamic acid (DDTC). Pentylmagnesium bromide is used to derivatize the non-volatile organotin-carbamate complexes. A detection limit of 2.5 ng/g (as Sn) can be achieved. The optimization of the different parameters is discussed and the accuracy of the method was validated by the analysis of two certified reference materials. A first approach was made to determine tri- and dimethyltin compounds forming extractable complexes with NaDDTC under pH controlled conditions.