Separation+of+55Fe

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 * 1) Elute 2 g of ion exchange resin with 8 ml of 8 M HNO 3 overnight. Separate the resin by filtration.
 * 2) Take 1 ml of the solution into a centrifuge tube and add 10 mg Fe-carrier (FeCl 3 ) and dilute with water to total volume of 10 ml. Take a 100 µL sample for AAS/ICP-MS/ICP-OES measurement.
 * 3) Add drop by drop concentrated ammonia until Fe(OH) 3 precipitates (pH 8-9 ). Centrifuge the sample for a couple of minutes and discharge the supernatant.
 * 4) Dissolve the precipitate in 8 M HCl and transfer the solution into 100 ml extraction funnel. Extract the sample two times with 25 ml di-isopropyl ether. Discharge the aqueous phase.
 * 5) Combine the ether fractions and back-extract the iron into aqueous phase by extracting it twice with 15 ml of distilled water. Transfer the water solution into a centrifuge tube and discharge the ether fraction.
 * 6) Add ammonia to precipitate the iron (pH 8-9). Use a warm water bath to facilitate the precipitation. Centrifuge and discharge the supernatant. Wash the precipitate with small amount of water, centrifuge and discharge the rinse water.
 * 7) Dissolve the precipitate in 5 ml 0.2 M HCl in a warm water bath.
 * 8) Pour the solution into an ion exchange column (Dowex 50 w x 4; 50/100, pretreated with 20 ml of 0.2 M HCl). Wash the column with 10-20 ml of 0.2 M HCl.
 * 9) Elute the iron from the column with 40 ml of 0.5 % oxalic acid into a centrifuge tube.
 * 10) Add a drop of 30 % hydrogen peroxide. Precipitate the iron with concentrated ammonia on a warm water bath. Centrifuge and discharge the solution.
 * 11) Dissolve the residue into a small amount of strong HF. Transfer the sample into a liquid scintillation vial (weighed before addition). Add 1 mL of distilled water, weigh the sample.
 * 12) Take a 100 µL sample for the iron measurement with AAS/ICP-MS/ICP-OES.
 * 13) Measure the activity of 55 Fe from the rest of the sample by liquid scintillation counting.