Simultaneous Determination Of Uranium Research Articles

Simultaneous Determination of Uranium and Depleted Uranium Isotopic Ratio Using Inductively Coupled Mass Spectrometry.

We have developed and validated a method for the simultaneous quantitative measurement of total uranium (TU) and uranium 235 U/238 U isotopic ratio (UIR) in urine by inductively coupled plasma mass spectrometry (ICP-MS) using a Thermo Scientific iCAP-Q instrument. The performance characteristics of the assay were determined to be in compliance with clinical laboratory standards. The assay was linear in the concentration range of 1.0 to 500.0 ng/liter TU. The method was precise and accurate with limits of detection of 2.5 ng/liter for TU and 9.8 ng/liter for UIR. The accuracy was >93% and the coefficient of variation (% CV) was <5.0% for both TU and UIR. All results were within established guidelines and agreed-upon criteria, and the results fell within the certified range for the reference controls. The method has thus been shown to be effective as a simple, precise, and sensitive analytical technique for testing urine samples. © 2018 by John Wiley & Sons, Inc.

Sensitization of uranium fluorescence using 2,6-pyridinedicarboxylic acid: Application for the determination of uranium in the presence of lanthanides

The 2,6-pyridinedicarboxylic acid (PDA) has been shown to efficiently sensitize and enhance the fluorescence of uranium in aqueous medium. Interestingly, this ligand stabilizes the UO 2 2+ species, which without the ligand is known to be in a negligible concentration, in aqueous medium at pH 6. The ligand sensitized enhancement of UO 2 2+ fluorescence by PDA, provides an analytical tool for the determination of uranium at trace levels, in aqueous medium. Furthermore, PDA is also known to enhance the fluorescence of lanthanides; consequently, the simultaneous determination of uranium and lanthanides, using PDA as a fluorescence sensitizing agent, becomes a possibility, which has been demonstrated in this work. We have shown that the use of PDA yields detection limits of 2.2×10 −7 M for UO 2 2+, 1×10 −8 M for Tb 3+ and 5×10 −9 M for Eu 3+ in the simultaneous determination of these analytes.

Simultaneous Spectrophotometric Determination of Uranium and Thorium Using Arsenazo III by H‐Point Standard Addition Method and Partial Least Squares Regression

AbstractSimultaneous determination of uranium and thorium using arsenazo III as a chromogenic reagent at pH 1.70 by H‐point standard addition method (HPSAM) and partial least squares (PLS) calibration is described. Under optimum conditions, the simultaneous determinations of uranium and thorium by HPSAM were performed. The absorbencies at one pair of wavelengths, 649 and 669 nm, were monitored with the addition of standard solutions of uranium. The results of applying the HPSAM showed that uranium and thorium can be determined simultaneously with weight concentration ratios of uranium to thorium varying from 20:1 to 1:15 in the mixed sample. By multivariate calibration methods such as PLS, it is possible to obtain a model adjusted to the concentration values of the mixtures used in the calibration range. In this study, the calibration model is based on absorption spectra in the 600–750 nm range for 25 different mixtures of uranium and thorium. Calibration matrices contained 0.10–21.00 and 0.25–18.5 μg mL−1 of uranium and thorium, respectively. The RMSEP for uranium and thorium were 0.7400 and 0.7276, respectively. Both proposed methods (HPSAM and PLS) were also successfully applied to the determination of uranium and thorium in several synthetic and real matrix samples.

Procedure for Simultaneous Determination of Uranium and Transuranium Elements in Groundwater and Liquid Radioactive Wastes from the Shelter

An ion-exchange procedure for simultaneous determination of 234U, 235U, 236U, 238U, 238Pu, 239 + 240Pu, 241Am, and 244Cm in groundwater and liquid radioactive wastes is described. The concentration and separation of U and Pu are performed on AV-17 anion exchanger in the chloride form from 9 M HCl. Am and Cm are separated from rare-earth elements by step-by-step elution from KU-2 cation-exchange resin in the NH 4 + form with α-hydroxyisobutyric acid (pH 4.75). Finally, U, Pu, Am, and Cm are determined α-spectrometrically.

Simultaneous determination of trace uranium and vanadium in biological samples by radiochemical neutron activation analysis

A radiochemical neutron activation analysis (RNAA) for simultaneous determination of uranium and vanadium in a single sample at trace levels is described. The method is based on post-irradiation wet-ashing and solvent extraction of vanadium with N-benzoyl-N-phenyl-hydroxylamine reagent. From the remaining aqueous phase, uranium is extracted into a toluene solution of tri-n-butyl phosphate. The chemical yields are determined spectrophotometrically for vanadium and by gamma-counting of the added natural uranium carrier for uranium. The method was evaluated by the analysis of reference materials and the results showed a good agreement with the certified values. The method was applied to the determination of vanadium and uranium in five military total diet samples in Slovenia.

Simultaneous determination of uranium(VI) and thorium(IV) ions with carminic acid by bivariate calibration

A bivariate calibration method, has been applied to the simultaneous determination of U(VI) and Th(IV) ions as complexes with carminic acid by visible absorption spectrophotometry. The bivariate calibration method was applied satisfactorily to the determination of these ions in synthetic solutions simulating sulfuric acid leach solution obtained from uranium-thorium ores and the results were compared with those given by first derivative spectrophotometry. No significant advantages of any method were found.

Development of a pH titration method for the simultaneous determination of uranium, nitrate and free-acid in the feed solution of the sol-gel process of nuclear fuel fabrication

pH titration curves generated by slow addition of alkali to solutions containing varying concentrations of uranyl nitrate and nitric acid were studied using an autotitrator linked to a personal computer. A procedure with multiple choice of equations has been developed for the estimation of free acid, nitrate and uranium in pure uranyl nitrate solution by a single titration. The technique provides a simple single-step method with required accuracy and precision for the simultaneous estimation of the three quantities in the uranyl nitrate feed solution of the sol-gel process for making UO3 microspheres. The relative standard deviations in the determination of uranium and nitrate were ±0.82% and ±1.52%, respectively, in 15 determinations.

Simultaneous determination of uranium(IV) and thorium(IV) ions with Arsenazo III by partial least squares method

A multivariate calibration method, Partial Least Squares Type 1 (PLS-1), is proposed for simultaneous spectrophotometric determination of uranium and thorium ions as their complexes with arsenazo III in hydrochloric acid medium. Several data characteristics are taking into account in order to minimize the optimum number of factors required for the construction of calibration model, while using various statistical criterions of selection. Finally, the evaluated calibration model is satisfactorily applied to determination of these ions in samples that resemble sulfuric acid leach solution obtained from a uranium ore.

Simultaneous determination of uranium(VI) and thorium(IV) ions with carminic acid by the partial least squares (PLS-1 and PLS-2) methods

Two multivariate calibration methods, partial least squares types 1 and 2 (PLS-1 and PLS-2) have been applied to the simultaneous determination of U(VI) and Th(IV) ions as complexes with carminic acid by visible absorption spectrophotometry. The results obtained by application of different chemometric approaches are discussed. No significant advantages were found between the methods. The proposed methods were applied satisfactorily to the determination of these ions in synthetic solutions simulating sulfuric acid leach solutions obtained from uranium-thorium ores.

Simultaneous determination of uranium(IV) and iron(II) with a stopped-flow inductive kinetic spectrophotometric method

A kinetic method for simultaneous determination of multielements is proposed, and a procedure for simultaneous determination of uranium(VI) and iron(II) is established based on their inductive effect on the chromium(VI)-iodide redox reaction in weak acidic medium. The reaction was monitored with the stopped-flow spectrophotometric technique by using I3−-starch complex as indicator. The calibration graphs are linear for 0–3.6 μg.cm−3 U(IV), and 0–2.5 μg.cm−3 Fe(II), respectively. Most foreign ions, except for V(IV), Sb(III), do not interfere with the determination.

Simultaneous determination of uranium and thorium using 4-(2′-thiazolylazo)resacetophenone oxime as analytical reagent. A derivative spectrophotometric method

A first derivative spectrophotometric method has been developed for the simultaneous determination of uranium(VI) and thorium(IV) when present in the same solution using 4-(2′-tiazolylazo)resacetophenone oxime (TARPO) as analytical reagent without prior separation of any of the metals or using masking agents, etc. The method allows the determination of uranium and thorium in their mixtures in the range of 0–10 ppm each. Many common anions and cations even in large quantities do not interfere.

Simultaneous determination of uranium(VI) and thorium(IV) with carminic acid by derivative spectrophotometry

The reactions of uranium(VI) and thorium(IV) ions with carminic acid have been investigated. These ions react with carminic acid in neutral medium, forming colored complexes. The dark purple or red wine complexes show a high absorption in the visible region (597 nm U(VI) and 616 nm Th(IV)). Chemical variables that affect the reaction have been optimized. The spectral overlapping of the color of complexes has been resolved by first-derivative spectrophotometry. The simultaneous determination of uranium(VI) and thorium(IV) mixtures is accomplished by taking the derivative signal (“zero crossing”) at 597 nm for U(VI) determination and at 616 nm for Th(IV) determination, respectively. The method has been applied to Tyuyamonite ore, containing in the matrix both ions.

An Optimised Method for Simultaneous Determination of Uranium and Thorium in Urine and Faeces Samples

A fast and simple procedure for the simultaneous determination of alpha-emitting isotopes of thorium and uranium in human urine and faetal samples has been developed. The chemical treatment used to produce samples on discs suitable for counting in an alpha spectrometer is outlined. For both isotopes the lower limit of detection is 10 −3 Bq per litre of urine or per gram of faeces ash, and the chemical recovery is 85±3%

Simultaneous determination of uranium and thorium with Arsenazo III by second-derivative spectrophotometry

A derivative spectrophotometric method has been developed for the simultaneous determination of microgram quantities of uranium and thorium with Arsenazo III in hydrochloric acid medium. The second-derivative absorbances of the uranium and thorium Arsenazo III complexes at 679.5 and 684.4 nm are used for their quantification. Uranium and thorium, both in the range 0.1–0.7 μg/ml have been determined simultaneously with good precision. The procedure does not require separation of uranium and thorium, and allows the determination of both metals in the presence of alkaline-earth metals and zirconium, but lanthanides interfere.

Simultaneous Determination of Uranium and HNO3Concentrations in Solution by Laser-Induced Fluorescence Spectroscopy

A simultaneous determination method of U and HNO3 concentrations by fluorescence spectroscopy was proposed. In the method, the former was determined from UO2 2+ fluorescence intensity which is proportional to UO2 2+ ion concentration and the latter from UO2 2+ fluorescence spectrum profile which depends on the NO3 − ion configuration around the UO2 2+ ion. The UO2 2+ fluorescence spectra were measured by a laser-induced fluorescence spectrometer which was capable of remote measurement by utilizing fiber optics. The fluorescence spectrum profiles were evaluated by normalized integrated fluorescence intensities in the wavelength region of 510∼650 nm. The U and HNO3 concentrations were determined in the ranges of 1∼200 mg/dm3 with an accuracy of 0.5 mg/dm3, and 0.75∼6.0 mol/dm3 with an accuracy of 0.1 mol/dm3, respectively.

Simultaneous determination of uranium and HNO3 concentrations in solution by laser-induced fluorescence spectroscopy.

A simultaneous determination method of U and HNO3 concentrations by fluorescence spectroscopy was proposed. In the method, the former was determined from UO2 2+ fluorescence intensity which is proportional to UO2 2+ ion concentration and the latter from UO2 2+ fluorescence spectrum profile which depends on the NO3 − ion configuration around the UO2 2+ ion. The UO2 2+ fluorescence spectra were measured by a laser-induced fluorescence spectrometer which was capable of remote measurement by utilizing fiber optics. The fluorescence spectrum profiles were evaluated by normalized integrated fluorescence intensities in the wavelength region of 510∼650 nm. The U and HNO3 concentrations were determined in the ranges of 1∼200 mg/dm3 with an accuracy of 0.5 mg/dm3, and 0.75∼6.0 mol/dm3 with an accuracy of 0.1 mol/dm3, respectively.

Simultaneous determination of U and Th by delayed fission neutron technique based on neutron generator

A method for simultaneous determination of uranium and thorium based on the deviation of their fission cross-section curves has been developed. Using a D-T neutron generator two different neutron spectra were produced with and without moderator around the target. The detection limits were found to be 0.044 mg and 0.25 mg in the presence of a moderator, while for fast neutrons 0.017 mg and 0.037 mg for uranium and thorium, respectively.

Simultaneous determination of uranium and thorium in ores by instrumental epithermal neutron activation analysis

Rapid scanning of numerous rock samples when prospecting for uranium and thorium ores can be facilitated by using the shorter-lived nuclides. The samples are activated during short epithermal neutron irradiations and the 20-min activities of 239U and 233Th are observed instrumentally with a small Ge(Li) detector. The detection limits for uranium and thorium are less than 1 ppm and 20 ppm, respectively.

Simultaneous determination of uranium, thorium, molybdenum, tungsten, arsenic, and antimony in granitic rocks by epithermal neutron activation analysis

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTSimultaneous determination of uranium, thorium, molybdenum, tungsten, arsenic, and antimony in granitic rocks by epithermal neutron activation analysisEiliv. SteinnesCite this: Anal. Chem. 1976, 48, 11, 1440–1443Publication Date (Print):September 1, 1976Publication History Published online1 May 2002Published inissue 1 September 1976https://doi.org/10.1021/ac50005a008RIGHTS & PERMISSIONSArticle Views76Altmetric-Citations26LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (550 KB) Get e-Alerts Get e-Alerts

Simultaneous determination of uranium and thorium by instrumental neutron activation and high resolution x-ray spectrometry

Reactor neutron activation followed by high resolution x-ray spectrometry has been applied to the nondestructive and simultaneous determination of uranium and thorium in geological materials. The L x-rays of Np and Pa obtained from neutron activated U and Th, respectively, were measured with a 100 mm/sup 2/ Si(Li) spectrometer. A limit of detection of 10/sup -2/ mu g for U and 10/sup -1/ mu g for Th was obtained by the irradiation of samples (~ 10 to ~ 100 mg) for 20 minutes at a neutron flux of 10/sup 13/n cm/sup -2/ sec/ sup -1/ and e mploying a 4% counting geometry. The accuracy of the assay is within a few per cent. The different sources of error, as well as the possibilities of minimizing them, were studied. (auth)