All reagents used were analytical grade. The detection of radioactive 63Ni was carried out by Liquid Scintillation Counting (LSC), using the Quantulus 1220 spectrometer, the vials used were the 20 mL polyethylene and the scintillation cocktail was the Optiphase Hisafe 3, all from PerKinElmer Inc. (PerkinElmer Inc., Finland). The column materials used in the analysis were Ni Resin in pre-packed 2 mL columns, 100-150 g particle size, an extraction chromatographic material available from Eichrom Technologies (USA) and the anion exchange resin Dowex 1×8, Cl — form, from Sigma-Aldrich Chemical Co., (USA). 59Ni was analyzed using Ultra-LEGe Detector (GUL) with a cryostat window of beryllium low energy y-detector containing an active area of 100 mm2, efficiency 5.9 keV for 55Fe with a resolution of 160 eV in terms of FWHM, from Canberra (USA). The recovery was obtained analyzing stable nickel by ICP-AES.