PB-210 AND PO-210 ANALYSIS IN SEDIMENTS AND SOILS BY MICROWAVE ACID DIGESTION

A microwave acid digestion method prior to the determination of Pb-210 and Po-210 in sediments and soils is described. It involves an acid ( HNO3, HCl, HF and H3BO3 mixture) digestion with microwave heating in c losed vessels at high pressures. Analyses carried out for various refe rence materials showed that the results were statistically equal to ce rtified values and reproducibility was also assured. The advantage of the microwave technique compared to the traditional leaching procedure s is that the solid materials are completely dissolved and, therefore, ca. 100% efficiency is achieved in the extraction of Po-210 and Pb-21 0, even though a fraction is associated to the silica net. Moreover, t ime of analysis is drastically reduced, as are the risks associated to vapour inhalation and material corrosion.