Radiochemical separation of thallium by amalgam exchange
TL;DR: In this article, an amalgam exchange technique was used for the radiochemical separation of thallium in the presence of fission products, achieving high yields of more than 95% while yields of contaminants, in most cases, were less than 0.1%.
Abstract: The radiochemical separation of thallium by an amalgam exchange technique was critically evaluated for the aqueous 0.5M sodium nitrate system. With an optimized procedure, thallium yields of more than 95% were obtained while yields of contaminants, in most cases, were less than 0.1%. The yield is relatively insensitive to interferences from mineral acids, alkalies, and salts, except for halogen acids, suifites, and oxidizing agents. At room temperature the procedure requires about 6 minutes while at 50 deg C it can be carried out in only 4 minutes. The application of this method to the separation of radiothallium in the presence of fission products requires about 8 minutes. The procedure appears to have useful potential for the separation of short-lived isotopes of thallium and can readily be modified for the determination of small amounts of thallium in various samples when used in conjunction with neutron activation analysis. (auth)
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12 citations
01 Sep 1971
TL;DR: In this article, a Methode berichtet, um eine Thalliumvergiftung and ihren Zeitpunkt in Abschnitten eines Kopfhaares bzw. Fusnagels durch Aktivierungsanalyse nachzuweisen.
Abstract: Es wird uber eine Methode berichtet, um eine Thalliumvergiftung und ihren Zeitpunkt in Abschnitten eines Kopfhaares bzw. Fusnagels durch Aktivierungsanalyse nachzuweisen. Die Abtrennung und Messung des Thalliums in den mit hoher n-Dosis bestrahlten Proben erfolgt durch Amalgamaustausch und Flussigszintillationszahlung des Tl-204. Bei Anwendung einer Neutronendosis von 2,59 · 1019 n/cm2 konnte eine zweimalige Thallium-Intoxikation im Einzelhaar nachgewiesen werden; die Erfassungsgrenze des Verfahrens liegt bei 10−4 μg bzw. 2–3 ppm Tl.
11 citations
10 citations
TL;DR: In this paper, a method was described which optimizes the parameters affecting the specificity and sensitivity of the radiochemical NAA of thallium in biological samples, which was applied to various materials as bovine liver, bone and nails.
Abstract: The determination of thallium in biological materials sometimes cause problems because of the low concentrations of this toxic element. In the present work a method is described which optimizes the parameters affecting the specificity and sensitivity of the radiochemical NAA of thallium in biological samples. High thermal neutron flux, complete decomposition of the organic matter by pressurized digestion, TlI precipitations, liquid extraction of HTlBr4 and La(OH)3 scavenging purification are the steps leading to the final homogeneous preparation of Tl2CrO4 for β-activity measurement. The method was applied to various materials as bovine liver, bone and nails. Good agreement was found between certified and determined thallium concentrations of the reference material CRM 176. The chemical yield comes to about 80%, with low deviations. The sensitivity of the method is about 10−3 μg/g, the standard deviations being in the range of 3.6% (CRM 176), 14% (bovine liver), and 17% (bone). Detailed working instructions are given.
7 citations
TL;DR: In this article, the preparation of TBP-plasticized polyurethane foam containing iodine or silver dithizonate was described and the effect of various factors on the exchange yield of radioiodide and radiosilver on the proposed reagent foams were critically investigated.
Abstract: The preparation of TBP-plasticized polyurethane foam containing iodine or silver dithizonate was described. Rapid isotope exchange separations of radioiodide and radiosilver on the plasticized iodine and silver dithizonate foams, respectively, were achieved by batch and column techniques. The effect of various factors on the exchange yield of radioiodide and radiosilver on the proposed reagent foams were critically investigated. The mobility of iodide ion in the iodine foam was proved to be high enough so that all the iodine coated membranes of the foam material are participating in the isotope exchange reaction and the equilibrium attained rapidly.
6 citations