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 absorption spectrometry (ETAAS) is presented. The separation is achieved on a strong cation‐exchange column with a 0.18 mol dm−3 solution of diammonium citrate at pH 6.5 with a step change to pH 4.0 in 60:40 methanol/water solvent. ETAAS detection is performed on‐line using an oxidizing matrix modifier. Mono‐, di‐ and tri‐butyltin may be determined in a single experiment with detection limits of (respectively) 0.5, 1.1 and 0.8 ng (Sn). Applications to actual samples are reported.