A study on the reproducibility of Tessier's 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; none of the methods applied proved optimal for all the metals determined. The concentrations of metals extracted by the various reagents were characterized by good reproducibility on species bonded to the carbonates, to iron and manganese oxides and in the residual; precision was lower in the other cases. The sequential extractions also showed a satisfactory mass balance.