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Spectrophotometric Determination of Cerium With Tiron

Description: A spectrophotometric method for the determination of cerium and Tiron (disodium-1,2-dihydroxybenzene-3,5disulfonate) was applied to the determination of cerium in samples which contain uranium and zirconium. The ceriumTiron complex in solutions of pH 8 or greater exhibits an absorption maximum of 500 m mu . This reagent does not react with any other lanthanive element. The interference of iron, uranium, and zirconium was eliminated by extracting these interfering elements with a solution of trioctylphosphine oxide in cyclohexane. (auth)
Date: June 14, 1957
Creator: McDowell, B. L.; Meyer, A. S., Jr. & White, J. C.
Partner: UNT Libraries Government Documents Department

DIRECT SPECTROPHOTOMETRIC DETERMINATION OF URANIUM IN CYCLOHEXANE SOLUTIONS OF TRI-n-OCTYLPHOSPHINE OXIDE

Description: A method for the direct determination of uranium in a cyclohexane solution of tri-n-octylphosphine oxide (TOPO) is presented. The adduct, UO/sub 2/ Cl/sub 2/ x 2TOPO, that is formed when uranium(VI) is extracted from hydrochloric acid solutions by tri-n-octylphosphine oxide absorbs light in the ultraviolet region. This absorbance is measured at 230 m mu vs. a TOPO-cyclohexane solution that was contacted with hydrochloric acid of the same concentration as that in the test aliquot. The molar absorbance index is 5500. The method is not selective; of the elements that are extracted by TOPO from hydrochloric acid, iron(III), zirconium, molybdenum, tin and thorium, only thorium can be tolerated. (auth)
Date: April 21, 1959
Creator: White, J. C.
Partner: UNT Libraries Government Documents Department

Automated fluorometer for uranium analysis

Description: An utomated fluorometer has proven to be a valuable analytical tool for analyzing natural waters for the Uranium Resource Evaluation (URE) project. Uranium is isolated from potential quenching ions and concentrated by extraction with tri-n-octylphosphine oxide (TOPO) in Varsol. A portion of the extract is placed on a sodium fluoride pellet which is then dried, sintered, and cooled. Sixteen samples can be analyzed in about 1.5 hours. The lower reporting limit has been set at 0.20 micrograms per liter (..mu..g/l).
Date: March 1, 1978
Creator: McElhaney, R. J.; Caylor, J. D.; Cole, S. H.; Futrell, T. L. & Giles, V. M.
Partner: UNT Libraries Government Documents Department

THE USE OF TRI-n-OCTYLPHOSPHINE OXIDE IN THE SOLVENT EXTRACTION OF THORIUM FROM ACIDIC SOLUTIONS

Description: Thorium is readily extracted by a solution of tri-noctylphosphine oxide in cyclohexane from either acidic nitrate or chloride solutions. The maximum extraction coefficient in a nitrate medium is 380 as compared to 1300 for a chloride solution. In nitrate media the extraction coefficient is relativelv unaffected by changes in the anion concentration. In chloride media the coefficient varies directly with increasing chloride concentration, i.e., from about 0.4 in one molar chloride to the maximum in 7 to 10 molar. The acid concentration should be at least one molar. Thorium is not appreciably extracted from sulfate solutions. The extraction coefficient is of the order of 0.3. The addition of nitrate or chloride increases the coefficient sufficiently so that essentially 99% of the thorium can be extracted in a single equilibration. In perchlolate systems the extractlon is most efficient in one molar acid. The maximum (The above was unscabble material)
Date: November 20, 1958
Creator: Ross, W.J. & White, J.C.
Partner: UNT Libraries Government Documents Department

Actinide removal from nitric acid waste streams

Description: Actinide separations research at the Rocky Flats Plant (RFP) has found ways to significantly improve plutonium secondary recovery and americium removal from nitric acid waste streams generated by plutonium purification operations. Capacity and breakthrough studies show anion exchange with Dowex 1x4 (50 to 100 mesh) to be superior for secondary recovery of plutonium. Extraction chromatography with TOPO(tri-n-octyl-phosphine oxide) on XAD-4 removes the final traces of plutonium, including hydrolytic polymer. Partial neutralization and solid supported liquid membrane transfer removes americium for sorption on discardable inorganic ion exchangers, potentially allowing for non-TRU waste disposal.
Date: January 1, 1986
Creator: Muscatello, A.C. & Navratil, J.D.
Partner: UNT Libraries Government Documents Department

Polonium-210 assay using a background-rejecting extractive liquid-scintillation method

Description: This paper describes a procedure which combines solvent extraction with alpha liquid scintillation spectrometry. Pulse shape discrimination electronics are used to reject beta and gamma pulses and to lower the background count to acceptable levels. Concentration of /sup 210/Po and separation from interferring elements are accomplished using a H/sub 3/Po/sub 4/-HCl solution with TOPO combined with a scintillor in toluene. (DLC)
Date: January 1, 1981
Creator: Case, C.N. & McDowell, W.J.
Partner: UNT Libraries Government Documents Department

Hybrid chemical and nondestructive analysis technique

Description: A hybrid chemical/NDA technique has been applied at the Los Alamos National Laboratory to the assay of plutonium in ion-exchange effluents. Typical effluent solutions contain low concentrations of plutonium and high concentrations of americium. A simple trioctylphosphine oxide (TOPO) separation can remove 99.9% of the americium. The organic phase that contains the separated plutonium can be accurately assayed by monitoring the uranium L x-ray intensities.
Date: January 1, 1983
Creator: Hsue, S.T.; Marsh, S.F. & Marks, T.
Partner: UNT Libraries Government Documents Department

Identification and separation of the organic compounds in coal-gasification condensate waters. [5,5 dimethyl hydantoin, dihydroxy benzenes, acetonitrile]

Description: A substantial fraction of the organic solutes in condensate waters from low-temperature coal-gasification processes are not identified by commonly employed analytical techniques, have low distriution coefficients (K/sub C/) into diisopropyl ether (DIPE) or methyl isobutyl ketone (MIBK), and are resistant to biological oxidation. These compounds represent an important wastewater-treatment problem. Analytical techniques were developed to detect these polar compounds, and the liquid-liquid phase equilibria were measured with several solvents. A high-performance liquid - chromatography (HPLC) technique was employed to analyze four condensate-water samples from a slagging fixed-bed gasifier. A novel sample-preparation technique, consisting of an azeotropic distillation with isopropanol, allowed identification of compounds in the HPLC eluant by combined gas chromatography and mass spectrometry. 5,5-dimethyl hydantoin and related compounds were identified in condensate waters for the first time, and they account for 1 to 6% of the chemical oxygen demand (COD). Dimethyl hydatoin has a K/sub D/ of 2.6 into tributyl phosphate (TBP) and much lower K/sub D/ values into six other solvents. It is also resistant to biological oxidation. Phenols (59 to 76% of the COD), dihydroxy benzenes (0.02 to 9.5% of the COD), and methanol, acetonitrile, and acetone (15% of the COD in one sample) were also detected. Extraction with MIBK removed about 90% of the COD. MIBK has much higher K/sub D/ values than DIPE for dihydroxy benzenes. Chemical reactions occurred during storage of condensate-water samples. The reaction products had low K/sub D/ values into MIBK. About 10% of the COD had a K/sub D/ of nearly zero into MIBK. These compounds were not extracted by MIBK over a wide range of pH. 73 references, 6 figures, 35 tables.
Date: August 1, 1983
Creator: Mohr, D.H. Jr. & King, C.J.
Partner: UNT Libraries Government Documents Department

Recovery and purification of nickel-63 from HFIR-irradiated targets

Description: The production of large quantities of high-specific-activity [sup 63]Ni (>10 Ci/g) requires both a highly enriched [sup 62]Ni target and a long irradiation period at high neutron flux. Trace impurities in the nickel and associated target materials are also activated and account for a significant fraction of the discharged activity and essentially all of the gamma activity. While most of these undesirable activation products can be removed as chloride complexes during anion exchange, chromium, present at [sup 51]Cr, and scandium, present as [sup 46]Sc, are exceptions and require additional processing to achieve the desired purity. Optimized flowsheets are discussed based upon the current development and production experience.
Date: June 1, 1993
Creator: Williams, D.F.; O'Kelley, G.D.; Knauer, J.B.; Porter, C.E. & Wiggins, J.T.
Partner: UNT Libraries Government Documents Department