Glenn E. Bentley

The production and recovery of 77Br at Los Alamos for nuclear medicine studies

Abstract A procedure for the synthesis and isolation of 77 Br for nuclear medicine research has been developed at LASL. Metallic Mo targets are irradiated at LAMPF with medium-energy protons at high beam current. Following dissolution, volatilization, precipitation, and ion exchange techniques, 77 Br is recovered with a (91±7)% chemical yield and is completely free of all other radioactive species with the exception of small levels of 76 Br and 82 Br. Ci-quantity production capabilities have been demonstrated, and the product is proving successful for the labelling of diverse radiopharmaceuticals. Future improvements in the process are also discussed.

Scope and limitations of a rapid radiobromination technique

A series of model compounds has been labeled with bromine-77 using a recently described method for rapid radiobromination. Characterization of the 77 Br-labeled products has shown the technique to be unsuitable for labeling fragile molecules, such as proteins. Thus, the technique should not be considered a generally applicable radiobromination method; however, it may be a useful means of attaching radiobromine to some simple molecules which are not sensitive to oxidative conditions and do not possess multiple sites for halogenation.

Generation of a Low Flow Atmospheric Pressure Neon ICP

Abstract A 27.12 MHz low flow (3 1/min), laminar flow, atmospheric pressure neon ICP has been generated. The forward power used is 500 W with a reflected power of less than 5 W. Using higher powers caused the plasma to either extinguish or form numerous filaments. The Hs line is used to determine an electron number density of 8 × 1013cm−3. The N2 +(0, 0) and OH(0, 0) transitions did not readily emit. This fact, coupled with the low electron density and low input power, indicates a relatively cool plasma.

Inductively coupled plasma—mass spectrometry drift correction based on generalized internal references identified by principal components factor analysis

Abstract Abstract factor analysis is applied to repeated measurements of inductively coupled plasma—mass spectrometry (ICP-MS) responses for several elemental masses in a multielement standard. During good operation, over 90% of the variance in response is accounted for by two or three factors. These factors tend to correlate with different mass ranges, and these correlations allow a rational basis for selection of candidates for internal reference elements. Internal references selected from these candidates were used to evaluate three different mathematical methods for correcting ICP-MS responses of all elements. The line ratio internal reference method and the analyte internal reference correlation method, which use a single internal reference for all elemental masses, improved precisions for most elements but decreased or had no effect on precisions of other elements. The generalized internal reference method, which may use more than one elemental mass in the correction calculation, improved precisions for all elements in most experiments.

CHAPTER 4 – RESEARCH-SCALE EXPERIMENTATION ON THE PRODUCTION AND PURIFICATION OF SPALLOGENIC 68Ge AT LOS ALAMOS FOR NUCLEAR MEDICINE APPLICATIONS

Abstract The 68Ge-68Ga generator system is of current interest in diagnostic nuclear medicine for positron emission tomography. The parent isotope is produced in high yield at LAMPF by the spallation of RbBr targets with medium-energy protons, and laboratory-scale experiments to develop a procedure for the recovery and decontamination of radiogermanium have been conducted. Following target dissolution, distillation, and solvent extraction techniques, purified 68Ge has been quantitatively obtained at microcurie activity levels. Initial experience in the hot-cell processing of production targets is also presented.

Continuous emissions monitoring of mixed waste incinerators

A system for the real-time monitoring of emissions from incinerators must be developed which can address the needs of the DOE community and others involved in mixed waste incineration. These needs are an outgrowth of the ever-increasing waste storage problems and the growing concern of the public, as witnessed by the stricter compliance requirements of federal and state agencies, that the products of incineration are hazardous to their health and injurious to the environment. This paper focuses on the technologies being developed here at Los Alamos and other laboratories which address the detection of a broad spectrum of toxic and hazardous chemicals.