Oughton, DSkipperud, LindisFifield, L KeithCresswell, RichardSalbu, BritDay, Philip2015-12-132015-12-130969-8043http://hdl.handle.net/1885/77950Generally low levels of plutonium in environmental samples, often combined with limited sample sizes, necessitate reliable low-level techniques for determination of Pu isotopes. Accelerator mass spectrometry (AMS) has proved to be a powerful method for measuring low-level Pu activity concentrations and Pu isotope ratios. Based on procedural blanks, detection limits for AMS were below 1fg Pu (equivalent to ca. 2μBq 139Pu), which can compete with both TIMS, high sensitivity ICP-MS, and certainly alpha-spectrometry, while showing less interference, memory and matrix effects as compared to routine ICP-MS techniques. In addition to low detection limits, the technique offers the advantage of giving information on Pu isotope ratios. Measurements of sediments collected from dumping sites at Novaya Zemlya showed deviation from global fallout 240Pu/239Pu ratios.Keywords: Environmental impact; Mass spectrometry; Plutonium; Sediments; Accelerator mass spectrometry (AMS); Environmental samples; Isotope ratios; Radioisotopes; plutonium 239; plutonium 240; accelerator mass spectrometry; accuracy; conference paper; mass spectro Accelerator mass spectrometry; Isotope ratios; Novaya Zemlya; Plutonium200410.1016/j.apradiso.2004.03.0542015-12-11