77Br is of potential use in diagnostic nuclear medicine as the parent of ultrashort-lived77mSe in a radioisotopic generator system. The chemical form(s) of the radiobromine in aqueous solution, and their radiation-induced chemical transformations, are of importance for biomedical generator development. Approximately 150 mCi of radiobromine, initially present as Br–, was studied over a period of three weeks and analyzed for BrO
(x=0–4) by anion exchange chromatography. Radiolysis of the solution gave rise to a small quantity of BrO
, but 99.5% of the activity remained as bromide.
A comprehensive radiochemical isolation procedure and data analysis/interpretation method for the nuclear forensic investigation
of Th has been developed. The protocol includes sample dissolution, chemical separation, nuclear counting techniques, consideration
of isotopic parent-daughter equilibria, and data interpretation tactics. Practical application of the technology was demonstrated
by analyses of a questioned specimen confiscated at an illegal drug synthesis laboratory by law enforcement authorities.
We have employed titration calorimetry to investigate the aqueous solution chemistry of the Th(IV) + oxalate coordination system. The enthalpies of formation of the two oxalic acid species and the first Th-oxalate complex have been measured at an ionic strength I=1.0M and temperature t=25°C. Corresponding entropy values were calculated from the van't Hoff equation, and a thermodynamic summary of the Th/H/oxalate system is presented in a table.
43K is used in diagnostic nuclear medicine for body electrolyte and cardiovascular investigations. This nuclide is produced
at LAMPF by the spallation of V targets with medium-energy protons, and a chemical procedure has been developed for the isolation
of radiopotassium from the bulk target material and various spallogenic impurities.43K is thus recovered with a 91% chemical yield and is sufficiently decontaminated for radiologic applications.
Authors:P. Grant, P. Robouch, R. Torres, and R. Silva
Instrumentation has been developed to perform uv-vis-nir absorbance measurements remotely and at elevated temperatures and pressures. Fiber-optic spectroscopy permits the interrogation of radioactive species within a glovebox enclosure at temperatures ranging from ambient to >100 °C. Spectral shifts as a function of metal-ligand coordination are used to compute thermodynamic free energies of reaction by matrix regression analysis. Pr3+ serves as a convenient analog for trivalent actinides without attendant radioactivity hazards, and recent results obtained from 20–95 °C with the Pr-acetate complexation system are presented. Preliminary experimentation on Am(III) hydrolysis is also described.
Authors:P. Grant, G. Montero, A. Newman, and H. O'Brien
The first use of the172Hf–172Lu generator system in industry is reported. Millicurie quantities of172Lu have been utilized for radiotracer studies of oil pipeline flow rates, refinery column residence times, and the performance of a coal liquefaction pilot plant.
Authors:P. Horlock, J. Clark, I. Goodier, J. Barnes, G. Bentley, P. Grant, and H. O’Brien
82Sr has now been produced by the spallation of Molybdenum by protons of up to 800 MeV. The radiochemical recovery of strontium
is described together with a description of the analytical techniques used to estimate recovered yields of the various radionuclides
generated. A radionuclide generator is described for the rapid recovery of82Rb, the 1.25 min half-life decay product of82Sr. An outline is given of the quality control procedure adopted to ensure that the82Rb is suitable for clinical use.
Authors:G. Klunder, J. Andrews, M. Church, J. Spear, R. Russo, P. Grant, and B. Andresen
Capillary electrophoresis has been used to separate metal ions characteristically associated with nuclear fission. Electrokinetic
injections and transient isotachophoretic techniques were employed to increase sample loading and provide on-column concentration
of the analyte. On-line concentration factors of approximately 700-fold have been achieved. Indirect-UV absorbance, on-line
radioactivity, and indirect laser-induced fluorescence detection were used to monitor analytes of interest. The radioactivity
detector consists of a plastic scintillator and photomultiplier tube with a 4π detection geometry. The efficiency was determined
to be approximately 80%, enabling samples resident in the detector window for 0.1 minutes to be reliably assayed. Detection
of152Eu and137Cs was achieved at the low nCi level. Indirect fluorescence was performed with quinine sulfate as the background fluorophor
with α-hydroxysobutyric acid added as a complexing agent. An argon ion laser was used as the excitation source with a diode
array detector. Limits of detection for La3+, Ce3+, Pr3+, Nd3+, Sm3+, and Eu3+ were determined to be in the sub — 10 ppb range (6–11 nM) with indirect laser-induced fluorescence detection.
Authors:P. Grant, R. Whipple, F. Bazan, J. Brunk, K. Wong, R. Russo, and B. Andresen
Forensic analyses of debris from the fatal explosion of an electrochemical cold fusion cell at SRI International were conducted at LLNL at the request of Cal-OSHA. One investigation focused on the possibility of conventional nuclear reaction mechanisms contributing to the total energy inventory of the incident. Selected metal components of the electrolysis apparatus were subjected to nondestructive -ray spectrometry with high-sensitivity, low-background Ge detector systems. The anticipated analytes in these studies were radioactivation products potentially induced in the explosion residue by either fast or thermal neutrons. The results of this investigation were negative within the temporal constraints of the incident and the analytical sensitivities of the instrumentation.
Authors:P. Grant, R. Daniels, W. Daniels, G. Bentley, and H. O’Brien
A solvent extraction system has been developed for the separation of172Lu from its long-lived172Hf parent. The parent-daughter pair in equilibrium is maintained in a solution of HDEHP, and the heavy lanthanide daughter
is extracted into 9M HCl. The separation factor for this generator is approximately 104. The rare-earth activity so obtained is proposed for compound labelling research and animal biodistribution studies in nuclear