THE PERFORMANCE OF AN ANALYTICAL METHOD FOR DETERMINATION OF TBT DURING A 6-YEAR MONITORING PROGRAM

Tributyltin (TBT) concentrations have been measured in UK waters, shellfish and sediments during the period 1986-1992. The methodology was based on conversion of alkyltin compounds to hydrides following extraction, and then measurement by gas chromatography with flame photometric detection. The collection of a large set of data to assess changes in environmental concentrations of organotins required use of good analytical quality control procedures at a time when no reference materials were available. An analytical quality control (AQC) system based on in-house quality control materials was devised and the performance of the method independently assessed by periodic participation in intercalibration exercises with other expert laboratories.