Iranian Chemical Society Determination of Butyltin Stabilizers in PVC Using Liquid-Phase Microextraction with Electrothermal Atomic Absorption Spectrometry

A rapid and highly sensitive method is described for the extraction and determination of diand tributyltin in PVC samples using headspace liquid phase microextraction followed by an analysis with graphite furnace atomic absorption spectrometry (HSLPME/GFAAS). The analytes were derivatized in situ with sodium tetraethylborate and concentrated in a 2 μl microdrop of benzyl alcohol suspended from the tip of a conventional GC microsyringe. The ethylated species then were directly transferred into a graphite furnace and quantified. The extractions were carried out for 5 ml sample solution (8 ml vial) adjusted at pH 5, with derivatization at 22 oC for 15 min in a 2% sodium tetraethylborate. The experimental parameters impacting the performance of HS-LPME were also investigated. According to the analysis, the linearity range was from 5.0 to 250.0 ng l with a detection limit of 0.5 ng l for dibutyltin and from 1.7 to 170.0 ng l with a detection limit of 0.17 ng l for tributyltin. Method RSD values were below 1.5%. Finally, the analysis of spiked PVC and water samples revealed that matrix had little effect upon extraction.