Simultaneous Determination of Transuranium Radionuclides in Urine by Tandem Quadrupole ICP-MS/MS with Mass-Shift Mode Combined with Chemical Separation

The urine bioassay method for transuranium nuclides (Np-237, Pu-239,Pu-240,Pu-241, Am-241, and Cm-244) is needed to quickly assess the potential internal contamination in emergency situations. However, in the case that the analysis of multiple radionuclides is required in the same sample, time-consuming/tedious sequential analytical procedures using multiple chromatographic separation resins would have to be employed for the separation of every single radionuclide. In this work, a rapid method for the simultaneous determination of transuranium nuclides in urine was developed by using triple quadrupole inductively coupled plasma mass spectrometry (ICP-MS/MS) combined with a single DGA resin column. The chemical behaviors of Np/Pu and Am/Cm on the DGA resin were consistent in 8-10 mol/L HNO3 and 0.005-0.02 mol/L NaNO2 when Pu-242 and Am-243 were selected as tracers for Np/Pu and Am/Cm yield monitoring. Based on their different reaction rates with O-2, Np-237, Pu-239,Pu-240,Pu-241, Am-241, and Cm-244 in the same solution were simultaneously measured by ICP-MS/MS in the same run. The elimination efficiency of U-238(+) tailing (7.43 x 10(-9)), (UHO2+)-U-238-H-1-O-16/(UO2+)-U-238-O-16 (8.11 x 10(-8)) and cross contamination of Pu-241 and Am-241 (<1%) were achieved using 10.0 mL/min He-0.3 mL/min O-2 even if the eluate was directly measured without any evaporation. The detection limits of transuranium nuclides were at the femtogram level, demonstrating the feasibility of ICP-MS/MS for simultaneous transuranic radionuclides urinalysis. The developed method was validated by analyzing the spiked urine samples.