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Cancer continues to be a leading cause of global death despite decades of research on its prevention and cure. In the mid-twentieth century, anecdotal evidence began to accumulate that certain chemicals might be cancer-causing and this was followed up with animal model studies. These suspected substances were termed carcinogens and among those investigated were N-nitrosamines (or simply nitrosamines). Interest in nitrosamines is now more than a century old and research continues to explore their biology. Since the 1950's, steady progress has been made in perfecting chemistry techniques to label interesting compounds with 14C or tritium. However, there have been relatively few reports concerning the synthesis of nitrosamines with these radioisotopes, providing substances which could be valuable in advancing key nitrosamine biology research. Most of the previous literature examples of 14C or tritium labelled nitrosamines related to very specific compounds lacking wider interest and relevance. Also, the resulting products were usually of low specific activity. This paper outlines strategies to accomplish the labelling of more broadly relevant nitrosamines with 14C or tritium at high specific activity. Particularly, a library of 14C labelled nitrosamines with diverse structures was created. Exemplary experimental details are provided for the synthesis of [14C] N-nitrosodiethanolamine as well as the repurification of [ethyl-1-14C] N-nitroso-N-ethylurea. The storage and general stability of 14C nitrosamines is also discussed. Finally, as an example of a typical strategy to prepare a nitrosamine labelled with tritium, the synthesis of [3, 4-3H] N-nitrosopyrrolidine is described in detail. [ABSTRACT FROM AUTHOR]

Production of no-carrier-added (NCA) Pd, which will decay to Rh, was experimented using the Nb(B, 3n)Pd reaction. The 36 MeV boron beam on natural niobium generated 1 MBq/µA.h yield of Pd along with minute contaminants. A chemical separation method based on the liquid-liquid-extraction (LLX) was developed for the separation of trace amount of Pd from the bulk Nb. Stable isotopes of Pd and Nb were used to simulate the reaction with the help of inductively coupled plasma-optical emission spectroscopy (ICP-OES). A high separation factor (~10) was achieved at the optimum separation condition. [ABSTRACT FROM AUTHOR]

Idaho National Laboratory (INL) produces Xe, Xe, Xe, and Xe standards for the calibration and testing of the collection equipment and analytical techniques used to monitor radioactive xenon emissions. At INL, xenon is produced and collected as one of several spontaneous fission products from a Cf source in a stagnant volume of pressurized helium. Solids are separated from gases by sintered steel filtration. Further chromatographic purification of the fission gases separates the xenon fraction for selective collection. An explanation of gas system, separation, and purification is presented. Xe and Xe activity ratio adjustments are explained. [ABSTRACT FROM AUTHOR]

This paper describes ultrapurification of isotopically enriched calcium and molybdenum compounds and CaMoO calcium molybdate growth charge in order to remove radioactive uranium, thorium, and radium impurities. CaMoO single crystals grown from such charges are needed for the fabrication of scintillator elements of the cryogenic detector for the AMoRE project: a search for Mo neutrino-less double-beta decay. [ABSTRACT FROM AUTHOR]

Perchloric acid was found to be a suitable medium for the quantitative leaching of Sr(II) from homogeneous and calcined (Th,Sr)O particularly with respect to the contamination from Th(IV). Sr is a cause of major concern to the environment due to its long half life (28.6 years), significant abundance in large inventory of spent nuclear fuels (~350 thousand tons) awaiting geological disposal and its chemical similarity to Ca(II), an essential element for the living beings. Application of Sr as a parent radionuclide for Y (used in therapy radiopharmaceuticals) is possible provided it can be made available at desired high purity. In this context, the distribution coefficients of Sr(II), Th(IV), Zr(IV), Y(III), Eu(III) and Cs(I) were determined using Sr selective crown ether 4,4′(5′)-di -tert-butyl -dicyclohexano -18 -crown -6 by solid-liquid extraction in perchloric acid medium. Feasibility of employing extraction chromatography using Sr selective resin for the recovery and purification of Sr(II) from leached perchloric acid medium was explored. Perchloric acid medium is better than nitric acid medium for the uptake of Sr by Sr selective chromatographic resin under varying loading conditions of Sr(II). Similarly pH 2 solution appears better eluent of Sr(II) than distilled water. Present work offers a novel approach for setting up a Sr-Y generator. [ABSTRACT FROM AUTHOR]

Neutron irradiation of a natural Sm target is performed to produce Sm. Ion-exchange chromatography is used to separate Sm from Eu radionuclides produced in the process. To prepare a target, SmO powder is dissolved in 0.2 ml of HNO in a quartz vial. Samarium is deposited onto the vial walls by passing nitrogen gas at 120°C. The prepared samarium target is encapsulated in aluminum foil and irradiated in a 5-MW reactor in 5 × 10 n cm s flux. The irradiated target is dissolved in 1 M HCl, and the produced radioisotopes are determined with an HPGe nuclear detector. Finally Sm is separated from Eu radionuclides with Sm recovery yield of more than 66% and purity better than 99.8%. [ABSTRACT FROM AUTHOR]

Potassium nickel hexacyanoferrate(II) matrix was prepared and characterized. Purification of neutron-activation Mo–molybdate(VI) solutes from some residual cross-contaminant radionuclides including Cs, Rb, Sb, Co and Cr was carried out onto small chromatographic columns of the matrix (each of 1.0 g). Gamma-ray spectrometric analysis data showed that the purification process was not affected by either Mo(VI) concentrations (0.13 and 0.02 M Mo) in the feeding solution of 3.5 M NaNO at pH 9.5 or flow rates (0.2 and 5.0 mL/min) at room temperature. Molybdenum(VI) average loss onto the column matrix did not exceed 7.7 × 10 mmol Mo. Except for Cr, the matrix has very high selectivity for Cs, Rb and Sb with ~50% Co elimination. The obtained data were briefly discussed. [ABSTRACT FROM AUTHOR]

In order to search for isotopic anomalies of U caused by the disintegration of 247Cm in meteorite samples, an analytical scheme for determining 235U/238U ratio for a small amount of uranium (less than 1 ng U) was established. The isotopic ratio of U was determined by double-focusing inductively coupled plasma mass spectrometry (DF-ICP-MS). With a great improvement of chemical procedure for purifying the uranium fraction separated from meteorite samples, a variation in 235U/238U ratios was resolved at an order of ±4‰ for 100 ppt or 200 pg U in solution. For applying the procedure in searching an evidence of 247Cm as an extinct radionuclide in the early solar system, a selective chemical dissolution of constituent minerals of meteorites using EDTA and HCl was introduced and a chemical purification scheme of uranium for ICP-MS was established. [ABSTRACT FROM AUTHOR]