Use of accelerated solvent extraction for determination of ecological important phosphorus in lake sediments

Phosphorus has been identified as one of the most important elements in eut rophication of lakes. and the bulk of phosphorus compounds stored in lake s ediment contribute to a large extent to this process. It is therefore of gr eat interest to get an adequate estimate of the amount of potentially mobil e phosphorus for future release from lake sediment. The traditional analyti cal technique, which is both labour and time consuming, consists of differe nt steps of liquid/solid extractions. The total extraction time for the pro cedure used today is as long as three days. The recently developed accelera ted solvent extraction technique has in this study been applied to effectiv ely extract the mobile forms of phosphorus in sediments. By using a buffere d dithionite solution at 25 degrees C followed by water at 100 degrees C as solvents in sequential extractions, the total extraction process was compl eted within 90 minutes. The feasibility of using aqueous solutions and wate r as solvents with this technique is demonstrated here for the first time. The results obtained have been comparable to extractions resulted from the traditional techniques used to define and quantify the different amounts an d forms of phosphorus in sediment.