Butyltin compounds in retail mollusc products.

Butyltin was found in 62 of 74 mollusc products purchased from major supermarket outlets in seven cities across Canada. Tribuyltin was detected in 41 samples, with levels up to 233 ng g(-1). Dibutyltin and monobutyltin levels ranged up to 88 and 53 ng g(-1), respectively. Products originating from East and South East Asia generally contained the highest levels. Gastropods contained lower levels than other molluscs. Enzymatically hydrolysed samples were extracted with 0.05% tropolone in hexane-diethyl ether (1 : 1). Ethyl derivatives were made by Grignard reaction and analysed by gas chromatography coupled to an atomic emission detector. Gas chromatograph-mass spectrometry confirmed the presence of butyltins in the mollusc samples.