The measurement of the fission product cesium isotopes 135Cs and 137Cs at low femtogram (fg) 10-15 levels in ground water by Inductively Coupled Plasma-Mass Spectrometry ICP-MS is reported. To eliminate the potential natural barium isobaric interference on the cesium isotopes, in-line chromatographic separation of the cesium from barium was performed followed by high sensitivity ICP-MS analysis. A high efficiency desolvating nebulizer system was employed to maximize ICP-MS sensitivity ~10cps/femtogram. The three sigma detection limit measured for 135Cs was 2fg/ml (0.1uBq/ml) and for 137Cs 0.9fg/ml (0.0027Bq/ml) with analysis time of less than 30 minutes/sample. Cesium detection and 135/137 isotope ratio measurement at very low femtogram levels using this method in a ground water matrix is also demonstrated.
Revised: March 16, 2010 |
Published: October 1, 2009
Citation
Liezers M., O.T. Farmer, and L. Thomas. 2009.Low level detection of Cs-135 and Cs-137 in environmental samples by ICP-MS.Journal of Radioanalytical and Nuclear Chemistry 282, no. 1:309-313.PNNL-SA-65705.