Rapid uranium preconcentration and separation method from fresh water samples for total U and 235U/238U isotope ratio measurements by ICP-MS.

A simple and rapid method using TRU resin cartridges (Eichrom Technologies, Inc., USA) and quadrupole ICP-MS for total uranium (U) and 235U/238U isotope ratio measurements in fresh water samples was investigated. After U extraction on the resin by sample solution loading, three alkaline reagents, tetramethyl ammonium hydroxide (TMAH), NaOH and NH4OH were studied for U elution behavior from the resin cartridges and applicability of these eluates was evaluated with respect to direct introduction to ICP-MS. Among the studied eluants, TMAH showed the best results with high U recovery and no counting interferences with internal standard elements such as thallium and bismuth. Moreover, U in water samples was separated from many major and minor elements with the TRU cartridges. Almost all U was concentrated in 10 mL of 0.014 M TMAH in 2 h using 200 mL of water sample.