Homogeneous liquid–liquid extraction of uranium(VI) from acetate aqueous solution
1999; Elsevier BV; Volume: 387; Issue: 1 Linguagem: Inglês
10.1016/s0003-2670(99)00038-0
ISSN1873-4324
AutoresAtsushi Takahashi, Yasuo Ueki, Shukuro Igarashi,
Tópico(s)Radioactive element chemistry and processing
ResumoA selective and very effective concentration method for uranium(VI) was developed by the homogeneous liquid–liquid extraction method based on the ion-pair phase separation of perfluorooctanoate ion (PFOA−) with tetrabutylammonium ion (TBA+). Under the experimental conditions ([PFOA−]T=6.67×10−3 M, [TBA+]T=5.0×10−2 M, [acetate]T=0.17 M, pH 4.0), the extraction % of uranium(VI) was 96%, and the maximum concentration factor was approximately 330-fold (i.e., 90 μl of the sedimented phase was produced from 30 ml of the aqueous phase). The extracted species was estimated by the normal liquid–liquid extraction method in a water/ethyl acetate system to be UO2(CH3COO)−3·TBA+. The proposed homogeneous liquid–liquid extraction method was applied as a preconcentration method for the spectrophotometric determination of uranium(VI) with arsenazo III. The calibration graph was linear over the range 3.3×10−8–2.7×10−6 M. The relative standard deviation for the central value of the calibration graph was 1.4% (10 determinations), and the detection limit (S/N=3) was 6.0×10−10 M. When the proposed method was applied to the separation and determination of uranium(VI) added to sea water, the results were satisfactory.
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