A method for the rapid radiochemical analysis of uranium and thorium isotopes in impure carbonates

El-Yahyaoui, Ahmed; Zarki, R.; Chiadli, A.

doi:10.1016/s0969-8043(02)00240-3

Cited by 9 publications

(4 citation statements)

References 13 publications

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“…In this last correction methodology, there is only a difference relating to the origins of the interference gamma rays at 143. 7 Th in the samples, the gamma-ray spectrometer with an n-type Ge detector was calibrated with the use of the multi-nuclide standard to obtain an FEP efficiency curve. Because this well-known efficiency calibration with the use of a multinuclide standard source enables almost accurate efficiency results for the unknown gamma-ray energies.…”

Section: Methods For Spectral Interference Correctionsmentioning

confidence: 99%

Methods for spectral interference corrections for direct measurements of 234U and 230Th in materials by gamma-ray spectrometry

Yücel

Solmaz

Köse

et al. 2009

Radiation Protection Dosimetry

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When the high-resolution gamma-ray spectrometry was used in the analysis of Th mainly due to self-absorption effects and the interfering lines from 226 Ra, 235U, 238 U and their decay products that often might be present in the samples. Therefore, in the present study, the methods for the spectral interference corrections for the analytical peaks of 234 U and 230 Th are suggested to take into account the contributions of the overlapping gamma rays to these peaks. For the method validation, direct gamma-ray spectrometric measurements were carried out using certified reference materials (CRM) by use of a 76.5 % n-type Ge detector. The activities measured for the CRM samples were corrected for spectral interferences, self-absorption and true coincidence-summing (TCS) effects. The obtained results indicate that ignoring of the contribution of the interference gamma rays to the main analytical peak at 53.2 keV of 234 U leads to a lager systematic error of 87.3-90.4 % for the measured activities of 234 U, and similarly if one ignores the contributions of the interference gamma rays to the main analytical peak at 67.7 keV of 230 Th, this leads to a much smaller systematic error of 2.1-2.7 % for the activities of 230 Th. Therefore, the required correction factors for spectral interferences to the analytical peaks of 234 U and 230 Th are not negligible and thus they should also be considered besides necessary self-absorption factors to determine more accurate activities in the samples. On the other hand, it is estimated that although the TCS effects on the main analytical peaks of both 234 U and 230 Th are negligibly small, those TCS correction factors for their interference gamma rays to these peaks should be taken into account when direct measurements are performed in a close-counting geometry condition. Otherwise, the resulted activities can have serious erroneous results for both 234 U and 230 Th while using gamma-ray spectrometry, thereby leading to inaccuracies in their derived quantities, for instance, the corresponding age determinations of the samples.

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Section: Methods For Spectral Interference Correctionsmentioning

confidence: 99%

Methods for spectral interference corrections for direct measurements of 234U and 230Th in materials by gamma-ray spectrometry

Yücel

Solmaz

Köse

et al. 2009

Radiation Protection Dosimetry

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“…The cell was dismantled, and stainless steel was rinsed with ethanol and then heated till red. The electrodeposition cell used was described previously [23]. An electropolished stainless steel of an exposed area of about 2.2 cm 2 was fitted in the cap of 30 mL polyethylene scintillation vial.…”

Section: Methodsmentioning

confidence: 99%

Preparation of U(VI) and Th(IV) alpha-sources from sea and fresh water samples by combining coprecipitation, solvent extraction and electrodeposition procedures

Zarki¹,

El-Yahyaoui²,

Chiadli³

2004

Radiochimica Acta

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Uranium / Thorium / Sea water / Fresh water / Coprecipitation / Iron hydroxides / Solvent extraction / Electrodeposition / α-particle spectrometry Summary. A simple method combining coprecipitation, solvent extraction and electrodeposition for determining uranium and thorium in sea water and fresh water samples is developed. It offers a considerable saving in time, minimising chemical treatment and costs. The analytical procedure consists of enrichment of U and Th by coprecipitation with iron(III) hydroxides and subsequent extraction by diethylether solution and electrodeposition of each actinide in the extracting organic phase in which it was separated.The dependence of the coprecipitation, the extractionelectrodeposition and the overall yields of the above mentioned elements is examined in relation to the initial aqueous solution acidity and various amounts of iron carrier. At an initial pH between 6 and 10, quantitative coprecipitation of U and Th requires use of an Fe(III) quantity which depends on the acidity of these solutions. This quantity varies, under explored conditions, between 10 and 110 mg/L. At a starting pH of 11, this coprecipitation becomes almost independent of Fe(III) amounts.The proposed procedure was used to analyse the content of U and Th isotopes in water samples. Recoveries of 60%-93% are obtained for uranium and 63%-86% for thorium. Good resolutions (37-56.5 keV) are also achieved under optimum conditions. These resolutions allow to make accurate determination of U and Th isotopes in various water samples.

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“…Here, for in vivo or in vitro diagnosis, very low analytical detection limits (DL) are demanded within nano‐ ranges. Various analytical methods have recently been sought for this purpose, including solvent extraction and electrodeposition procedures 7, mass spectrometry for the isotopic analysis of solid uranium 8, inductively coupled plasma‐mass spectrometry (ICP‐MS) 9, visible spectrophotometric determination of uranium 10, X‐ray fluorescence analysis 11, X‐ray fluorescence spectrometry 12, and quadrupole ICP‐MS (ICP‐QMS) 13. Some of these spectrophotometric methods are used for trace assays and isotope ratio detection, but they are complicated and time consuming and can be used only under laboratory conditions.…”

Section: Introductionmentioning

confidence: 99%

Radioactive uranium measurement in vivo using a handheld interfaced analyzer

Lee

Jung

2010

Enviro Toxic and Chemistry

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A trace uranium (U) detection method was developed with a handheld voltammetric analyzer that was the size of a mobile phone, with working sensors made of simple graphite pencil electrode (PE). The optimum stripping voltammetric conditions were sought, and the following results were obtained: 0.0 to 0.08 ng/L working ranges and a statistically relative standard deviation of 1.78% (RSD; n=15) at a 10.0 microg/L U spike. The experiment accumulation time used was only 150 s. Under this condition, the diagnostic detection limit approached 0.007 ng/L. The method was applied to soil of a natural rock in a radioactive mineralogy site. Earthworms that resided at this site were assayed. The method was found to be applicable in biological diagnosis or in real-time in vivo survey.

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A method for the rapid radiochemical analysis of uranium and thorium isotopes in impure carbonates

Cited by 9 publications

References 13 publications

Methods for spectral interference corrections for direct measurements of 234U and 230Th in materials by gamma-ray spectrometry

Methods for spectral interference corrections for direct measurements of 234U and 230Th in materials by gamma-ray spectrometry

Preparation of U(VI) and Th(IV) alpha-sources from sea and fresh water samples by combining coprecipitation, solvent extraction and electrodeposition procedures

Radioactive uranium measurement in vivo using a handheld interfaced analyzer

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