Determination of plutonium from different sources in environmental samples using alpha-spectrometry and AMS

A reliable and sensitive method for the determination of plutonium in environmental samples by a combined use of alpha-spectrometry and accelerator mass spectrometry (AMS) is presented. Different environmental samples contaminated with plutonium from the Chernobyl accident and other sources were investigated using both methods. Plutonium was chemically separated using extraction chromatography. As a chemical yield tracer, Pu-242 was applied for both AMS and alpha-spectrometry. After the alpha-spectrometric measurements, the samples were converted to targets suitable for the AMS measurements. AMS was especially chosen in addition to alpha-spectrometry, because it allows the determination of Pu-240/Pu-239 isotopic ratios as well as detecting the beta-emitting radionuclide Pu-241. Besides the generally used activity ratios of (238)pu/(239,240)pu, there are now further optional isotopic ratios available using this method. By combining AMS with alpha-spectrometry, all relevant plutonium isotopes can be measured. Thereby a reliable distinction of different sources of plutonium in the environment is possible. (C) 2009 Elsevier B.V. All rights reserved.