David Amouroux and his colleagues at the University of Pau in southern France have devised a strategy to completely analyse and quantify all alkylated tin compounds arising from landfill sites.

Organotin compounds are widely used as heat and light stabilisers in the production of plastic materials, as fungicides, pesticides, wood preservatives, and antifouling paints.

Unfortunately, contamination of the environment by such compounds both in households and in waste sites presents a problem owing to their severe toxicity and potential in the body.

The measurement of contamination has not been easy in the past, and previous methods only provided a reliable estimate for some organotin species, chiefly tributyl tin, owing to the complexity of samples.

Amouroux's method consists of three optimised steps: nitric acid extraction, derivatization, and chromatographic separation. As a result, a single analysis, with an addition of three isotopically enriched butyltin species, is all that is then required to provide a reliable measurement of the concentration of all alkyltins in a given sample. They tested the improved procedure on three French landfill sites.

Amouroux believes that 'such a methodology can be extremely useful to access the fate of organotin compounds, providing a specific, reliable and complete understanding of the environmental impact of this kind of effluent.'

Alan Holder