Plutonium / Uranium / Anion-exchange chromatography / Extraction chromatography / Alpha spectrometry / ElectrodepositionSummary An accurate and reliable analytical method has been developed for the measurement of low-level of plutonium nuclides (^''Pu, 239 -24oj>y^ in uranium Compounds and solutions by alpha spectrometry, with emphasis on the purification of plutonium nuclides from uranium isotopes and their a emitting decay radionuclides. The method mainly consists of Chromatographie separations. TWo steps of purification are necessary, the first one using a REILLEX™ HPQ (anion-exchange macroporous resin) Chromatographie column and the second one consisting in extraction chromatography with trioctylamine (TOA). ^"Pu was used as isotopic tracer: plutonium recovery yields for the entire process were found dose to 90% and the minimum detectable Pu activity was about lOmBq/sample for a counting time of 5 hours using a grid Chamber, after the implementation of a Separation with a good decontamination factor (higher than 10^) of plutonium vs. uranium. For a lower detection limit, it is necessary to increase the counting time.