DETERMINATION OF PLUTONIUM AND AMERICIUM IN MOSS AND LICHEN SAMPLES

A simple, sensitive and selective method is described for the simultan eous determination of plutonic and americium in lichen and moss sample s which can be used as the atmospheric radioactivity bioindicators. Pl utonium is separated from a HCl leaching solution by a Microthene-TNOA column; americium is separated by a KL-HDEHP column and purified by P MSP-TOPO extraction. A special attention has been paid to the decontam ination of plutonium and americium from Po-210. Ten lichen and 12 moss samples from tree trunks have been analyzed: starting from 2 g sample , the average yields and the detection limits were 70.2 +/- 12.5% and 28 mBq/kg for plutonium and 70.0 +/- 15.1% and 34 mBq/kg for american. The concentrations (mBq/kg) ranged from less than or equal to 28 to 4 960 for Pu-239,Pu-240, from less than or equal to 28 to 171 for Pu-238 and from less than or equal to 34 to 1930 for Am-241, respectively.