Determination of Fe-55 and Ni-63 using semi-preparative ion chromatography - a feasibility study

The feasibility of semi-preparative high-performance ion chromatography (HPIC) for the analysis of the activation products Fe-55 and Ni-63 in samples of different sources was studied. A mixed anion/cation exchanger column was applied to the separation of Fe(III), Ni(II) and Co(II) using 1 mmol/L PDCA-solution as an eluent. After fractionation of the eluate, Fe(III)- and Ni(II)-fractions were analysed by low-level liquid scintillation counting (LSC). The method was applied to the analysis of corrosion products originating from the primary circuit of a shut-down nuclear power plant. The limits of detection are dependent on the loading of metal ions on the column and are therefore given in terms of specific activities. For a typical sample composition they were found to be 0.011 Bq per mg Fe for Fe-55 and 0.054 Bq per mg Ni for Ni-63. An assessment of semi-preparative HPIC connected to off-line and on-line LSC as compared with standard radiochemical procedures is given.