Assessment of frozen storage of tributyltin in sea-water samples using hydride derivatisation

Abstract

Frozen storage of unfiltered natural sea-water samples fortified with tributyltin (TBT) leachate from antifouling paint was evaluated by the analysis of replicate samples selected randomly over a 678-d period using a hydride derivatisation purge and trap method. A previous study indicated that the precision of the analytical method is typically 15% and hence a greater than 15% loss of TBT is considered significant. Depending on whether a linear or exponential regression analysis of the data is carried out, a 15% loss apparently occurred after 170 or 90 d. After approximately 2 years of storage, the TBT concentration of samples had fallen by about 50%.