SPECIATION OF BUTYLTIN COMPOUNDS BY ION CHROMATOGRAPHY COUPLED TO ELECTROTHERMAL ATOMIC-ABSORPTION SPECTROMETRY

A new method for the determination of butyltin species by ion-exchange chromatography linked with graphite-furnace electrothermal atomic abs orption spectrometry (ETAAS) is presented. The separation is achieved on a strong cation-exchange column with a 0.18 mol dm-3 solution of di ammonium citrate at pH 6.5 with a step change to pH 4.0 in 60:40 metha nol/water solvent. ETAAS detection is performed on-line using an oxidi zing matrix modifier. Mono-, di- and tributyltin may be determined in a single experiment with detection limits of (respectively) 0.5, 1.1 a nd 0.8 ng (Sn). Applications to actual samples are reported.