Development of a harmonised phosphorus extraction procedure and certification of a sediment reference material

A harmonised procedure for the determination of the forms of phosphorus in freshwater sediments, developed in the frame of the European Programme, Sta ndards, Measurements and Testing (SMT) has been used for a certification ca mpaign for a reference material. This operationally defined scheme is a goo d compromise between method performance and reproducibility. Furthermore, t he method is rather simple to implement and could be used by water managers on a routine basis. A homogeneous and stable sediment reference material h as been prepared and will be available before mid 2001. The so-called SMT p rotocol, together with the reference material, are useful tools in the fiel d of water management, especially at a time when quality assurance is of pa ramount importance in laboratory analyses. Knowledge of the bioavailable fo rms of phosphorus is important not only for analysis of sediments but also for sludge and soils. Therefore, the SMT protocol could be extended to thes e materials.