Speciation of organotin compounds in shellfish by liquid chromatography -fluorimetric detection

A method for the determination of butyltin and phenyltin species in marine organisms by liquid chromatography is described. Analytes are extracted from the samples using ethyl acetate and hydrochloric acid. A clean-up step based on a solid-phase extraction using a cation exchange bonded phase has been developed to remove coextracted substances from the ethyl acetate extract. Determination is carried out by gradient elution on a silica-based C18 column with mobile phases consisting of methanol-water-acetic acid mixtures and using fluorimetric detection. The method, which allows the determination of the analytes at the ngg-1 level, has been applied to the analysis of diphenyltin, dibutyltin, triphenyltin and tributyltin in oyster and mussel tissues.