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 spect rometry. The compounds are released from the matrix by the action of a cetic acid and extracted into hexane after formation of an extractable complex with diethyldithiocarbamic acid (DDTC). Pentylmagnesium bromi de is used to derivatize the non-volatile organotin-carbamate complexe s. A detection limit of 2.5 ng/g (as Sn) can be achieved. The optimiza tion of the different parameters is discussed and the accuracy of the method was validated by the analysis of two certified reference materi als. A first approach was made to determine tri- and dimethyltin compo unds forming extractable complexes with NaDDTC under pH controlled con ditions.