Automatic sequential separation with an anion-exchange column for ultra-trace analysis of Pu, U, Th, Pb, and lanthanides in environmental samples

Sequential separation of 12 pg Pu and 50 ng of U, Pu, Th, Pb, and lanthanides in a calibration solution, with >93 % yield for the objective elements, was achieved within 6.3 h by an automatic system using a small anion-exchange column. The elements of interest in tree ring samples extracted from an 88-year-old pine tree were separated using this system, and 0.09 ng g −1 U was detected in the dry sample by inductively coupled plasma mass spectrometry. This separation technique is useful for ultra-trace quantitative and isotopic analyses of elements in small environmental samples.