Elution behavior of uranium from a TRU resin cartridge

In order to separate and concentrate uranium from environmental samples for determination of 235U/238U isotopic ratio by quadrupole ICP-MS, a TRU resin procedure was studied. A water sample (100-200 mL), acidified to 1M HNO3, was passed through the resin cartridge at 4-5 mL/min flow rate to extract U in the solution onto the resin, then, the cartridge was washed with 0.5M HCl. Most of the matrix elements in the sample solution were not retained on the resin when the sample solution was passed through, and all Th and some portions of the rare earth elements were eluted from the resin with the wash solution. For removal of U from the resin cartridge, 0-0.07M tetramethyl ammonium hydroxide (TMAH) was used. No elution of U with deionized water was observed, however, 10 mL of 0.07M TMAH could extract almost all the U from the resin cartridge. (author)