Separation of 55Fe
Measurement of 55Fe by Liquid-Scintillation Counting
Add 9.5 mL of scintillation cocktail Optiphase ’Hisafe’3 (LKB, Wallac). Shake well. Measure after ½ hour with a liquid scintillation counter.
To be able to calculate 55Fe radioactivity, counting efficiency need to be determined (efficiency calibration). Counting efficiency is determined from a 55Fe standard series using Fluorescein (C20H12O5) as a quenching agent.
A quenching standard series
Add reagents into plastic scintillation vials as follows:
Shake well. After ½ hour measure the samples in a liquid scintillation counter.
Draw a quenching standard quenching curve. Determine the counting efficiency for 55Fe from the curve.
Determination of Chemical Yield
Chemical yield of the analysis is determined by iron measurement of the 100 μL aliquot with AAS/ICP-MS/ICP-OES. Prepare iron standard (1, 2, 3, 5, 10 ppm) and measure them. Draw a standard curve. Measure your unknown sample and determine its iron content (ppm) from your standard curve. Calculate the yield (%). Take into account the dilution of the samples.
Describe in detail the whole separation procedure and explain why each step was made. Draw a separation procedure scheme.
Calculate the chemical yield of 55Fe separation.
Calculate the activity concentration of 55Fe in the resin and its uncertainty.
55Fe (X Bq/mL)