Characterisation of trace elements and methylmercury in an estuarine sediment reference material, IAEA-405.

An estuarine sediment sample, IAEA-405, was recently characterised for trace elements and methylmercury (MeHg) for ultimate use as a marine reference material. The reference values were calculated using data sets from 120 laboratories that participated in a world-wide intercomparison exercise. The data evaluation is highlighted, and includes comparisons of different analytical methods, as well as the distribution of data. Overall laboratory performance for this exercise was encouraging: 86 laboratories (72%) reported data with <25% outliers. There was sufficient acceptable data to establish recommended values for 17 elements and information values for a further 15 elements. In addition, a recommended value was established for methylmercury. The estuarine sediment sample, IAEA-405, can be used as a reference material for quality control in the determination of trace elements and methylmercury in moderately polluted sediments.