Stability of Technetium and Decontamination from Ruthenium and Molybdenum in Determination of 99Tc in Environmental Solid Samples by ICPMS

A rapid and efficient method for the determination of Tc-99 in environmental solid samples was developed using chromatographic separation combined with inductively coupled plasma mass spectrometry (ICPMS) measurement. The volatility of technetium during sample ashing and solution evaporation was investigated to establish a reliable sample pretreatment procedure. A novel approach was developed to improve the removal of molybdenum and ruthenium in chromatographic separation using 30% H2O2 pretreatment of the loading solution and extraction chromatographic separation using two serial small TEVA columns. The decontamination factors of more than 4 x 10(4) and 1 x 10(5) are achieved for molybdenum and ruthenium, respectively. Chemical yields of technetium in entire procedure range from 60% to 95% depending on the type and amount of samples, and the detection limit of 0.15 mBq/g for Tc-99 was obtained. The method has been successfully applied for the determinaton of Tc-99 in environmental solid samples.