Matrix contribution of environmental swipe materials for safeguard to uranium isotopic measurement

In order to investigate and quantify uranium content and isotope ratios in environmental swipe materials itself, the determinations of uranium isotope ratios in cotton swipes as well as working standard solutions are performed using multi collector inductively coupled plasma mass spectrometer (MC-ICPMS) and thermal ionization mass spectrometer (TIMS). We found that co-existing uranium in the swipes causes a serious shift of the measured data from the certified values. This study highlights the importance of mass balance correction for a precise uranium isotopic measurement of environmental swipe materials.