Evaluation of the state-of-the-art of butyl- and phenyltin compound determinations in freshwater sediment prior to certification of a reference material

In order to control the quality of butyl- and phenyltin compound determinat ions in sediment, the Standards, Measurements and Testing Programme (former ly BCR) of the European Commission has started a project, the final aim of which is to certify a freshwater sediment for its contents of a range of or ganotin compounds (mono-, di- and tributyltin, and mono-, di- and triphenyl tin). The first part of this project involved an interlaboratory study whic h aimed to test the feasibility of preparation of candidate freshwater sedi ment reference material and to detect and remove most of the pitfalls obser ved in organotin determinations. This paper presents the main results of th is interlaboratory study carried out prior to the certification campaign. T he agreement obtained among laboratories for the six compounds determined w as considered to reflect the state-of-the-art and was encouraging enough to decide upon the organisation of a certification campaign, which will be co ncluded in June 1999.