Standardization of 59Fe by efficiency extrapolation 4πβ-γ anticoincidence method

A solution of ⁵⁹Fe was standardized in the frame of a Bureau International des Poids et Mesures (BIPM) international key-comparison piloted by Asian Pacific Metrology Program (APMP) regional metrology organization. The method used was the live-timed 4πβ-γ anticoincidence counting with extended dead-time with efficiency extrapolation method. The confirmation of these results was performed by conventional 4πβ-γ coincidence counting with efficiency extrapolation and CIEMAT/NIST liquid scintillation counting methods. The value of the evaluated anticoincidence measurement was used to calibrate the LNMRI second standard ionization chambers for providing ⁵⁹Fe solutions to nuclear medicine canters in the procedures of anaemia diagnosis. Besides this value was adopted as the comparison value of LNMRI and sent to APMP organization. The half-life of ⁵⁹Fe was determined following the decay of one ampoule sample with ⁵⁹Fe solution in an ionization chamber (Centronic model IG12).