Extraction and determination of butylin compounds in shellfish by hydride generation—gas chromatography—quartz furnace atomic absorption spectrometry

Abstract

The method described involves the conversion of butyltin compounds extracted from shellfish into volatile hydrides by sodium tetrahydroborate, cryogenic trapping and selective volatilization followed by on-line quartz furnace atomic absorption spectrometric detection. Several sample pretreatment procedures were compared with emphasis on their accuracy, reproducibility and respect for the speciation of tin. Digestion with 0.083 M HCl in 16.7% methanol under sonication for 1 h is proposed. The recoveries of mono-, di- and tributyltin compounds from spiked mussel and oyster samples ranged from 96 to 99% with low degradation of butyltins (< 9%). Detection limits were in the 2–3 ng Sn g −1 (wet weight) range. The method was applied to wild and commercial samples of oysters. mussels and scallops and fairly high concentrations of butyltin compounds were measured.