A STUDY OF THE ANALYTICAL PARAMETERS IMPORTANT FOR THE SEQUENTIAL EXTRACTION PROCEDURE USING MICROWAVE-HEATING FOR PB, ZN AND CU IN CALCAREOUS SOILS

A four-step microwave extraction procedure, using microwave heating, f or Pb, Zn and Cu fractionation has been elaborated for calcareous soil s. This procedure distinguishes the metal fraction bound to carbonate, to iron and manganese oxides, to organic matter and the residual frac tion. Sample and analytical variances have been estimated to identify the anomalous metal contents in the light of the variation in the conc entration among the samples. Performances of each step of the method h ave also been calculated. The validity of the method was verified by a mass balance using calcareous soils and two certified reference mater ials. The results obtained were appropriate for the assessment of the environmental risks. (C) 1998 Elsevier Science B.V. All rights reserve d.