Fast separation and determination of 55Fe and 63Ni using chelating resin Chelex 100 for activated parts of nuclear reactors and nuclear forensics

In this study, a method for selective separation of ⁶³Ni and ⁵⁵Fe with simultaneous wash-out of ⁶⁰Co was developed. Purification of ⁶³Ni and ⁵⁵Fe was carried out using a chelating ion-exchange resin Chelex 100. The elaborated procedure was applied for aqueous and stainless steel matrices. Average recoveries were around 80% for both isotopes, confirmed by ICP-MS and LSC measurements. ⁶⁰Co, interfering with the isotopes spectra in the same energy range, was washed-out from the system prior to ⁶³Ni and ⁵⁵Fe separation. The most important advantages over existing methods are short separation time (c.a. 8 h), application of a single chromatographic column and overall simplicity.