English to Russian Other Other

For the isolation of U and Th isotopes a sequential extraction radiochemical method was employed, previously validated in our laboratory.
This radiochemical procedure is based on the use of chromatographic resins (UTEVA) manufactured by Eichrom3.
The radiochemical method employed is based on the reference method published by Pilvió and Bickel (2000)4, with some enhancements implemented in our laboratory.
For the determinations of U, Th and 210Po, ~ 0.5 g of each dry and homogenized sample were weighed and spiked with 232U, 229Th and 209Po as yield monitors.
Then, the aliquots were digested with hydrofluoric (HF) and nitric acid (HNO3) HF/HNO3 in Savillex® Teflon vials5, allowing the complete dissolution of many different types of geological material.
Figure 2.
High-resolution alpha-particle spectrometry (PIPS type)
After complete dissolution of the sample, the solution is evaporated until completely dry.
The sample residue is dissolved with 2 M hydrochloric acid (HCl) to which 200 mg of ascorbic acid is added.
The solution is recovered, evaporated until dry and the residue treated with HNO3 to destroy the ascorbic acid.
The sample residue is dissolved in 5 mL of 3M HNO3 and transferred to an UTEVA column preconditioned with 3M HNO3, this first eluate being then discarded.


Next, the column is first eluted with 5 mL of 9M HCl to convert the column to a chloride system and then it is eluted with 20 mL of the mixture 5 M HCl-0.05 M oxalic acid.