A STUDY ON THE REPRODUCIBILITY OF TESSIER EXTRACTIONS IN A FLUVIAL SEDIMENT AND A COMPARISON BETWEEN DIFFERENT DISSOLUTION PROCEDURES IN A REFERENCE MATERIAL

The reproducibility of Tessier's extractions and the total content of cadmium, chromium, copper, iron, manganese, lead, zinc and calcium in a river sediment have been evaluated. The metals were determined with AAS in flame and in graphite furnaces. The accuracy of the dissolution procedures was evaluated using a reference material (RM) BCR 145; non e of the methods applied proved optimal for all the metals determined. The concentrations of metals extracted by the various reagents were c haracterized by good reproducibility on species bonded to the carbonat es, to iron and manganese oxides and in the residual; precision was lo wer in the other cases. The sequential extractions also showed a satis factory mass balance.