Analytical Methods for Tributyltin in Sediments and Tissues

Analytical methodologies have been developed over the last decade to quantify tributyltin in sediments and tissues. The methods involve extracting the substance from solid matrices with either an organic solvent (sometimes acidified) or an acid. Tributyltin (TBT) is then converted to a more volatile compound, either an alkyl or hydride derivative to facilitate separation from potentially interfering compounds and subsequent detection by gas chromatography, atomic absorption spectrophotometry, or mass spectrometry. Detection levels reported vary by more than an order of magnitude, but accurate quantitation at concentrations <10 ng g-1 appears possible. Experiments conducted with oysters (Crassostrea virginica), exposed to TBT in the environment indicate that natural variability in TBT concentrations is such that ten replicates, were required to assess contamination at a station within a 95% degree of confidence.