The University of Missouri-Columbia (MU) Research (MURR) began operations in 1966 and has operated at 10 megawatts over 90 percent of the time since 1977. The MURR organizational structure includes reactor operations, health physics and technical service and research groups. The Nuclear Analysis Program is one of the major research areas and also includes mission components of teaching and service utilizing neutron activation analysis, isotope production and gamma-ray spectroscopy in the diverse study of both the physical and life sciences. *** DIRECT SUPPORT *** A0653133 00005
A series of five experiments were undertaken using several brands of fingernail and toenail clippers to determine if there was a potential source of contamination and interference in the ongoing dietary studies using nails from large cohort groups. A cleanup protocol was deemed sufficient to remove possible contamination.
The association of sub-optimal selenium status with increased riskfactors for some cancers has been reported in two recent epidemiological studies.In both studies the same threshold in selenium status was observed, belowwhich, cancer incidence increased. To assess the use of nails as a biologicmonitor to measure the long-term selenium status, an eight-year longitudinalstudy was undertaken with a group of 11 adult subjects, 5 women and 6 men.Selenium has been measured by instrumental neutron activation analysis. Differencesbetween fingernails and toenails will be discussed. In addition, the resultswill be discussed in the context of the long-term stability of the nail monitorto measure selenium status during those periods when selenium determinantsare static; and the changes that occur as a result of selenium supplementation.
A rapid instrumental system for measuring selenium via 17 second77mSe has been applied to the analysis of a wide variety of biological specimens encountered in biomedical research. The reliability
and versatility of the method is documented for serum and animal tissue specimens. Analysis results for SRM 1577 bovine liver
show excellent accuracy and precision.
A vapour phase bromination procedure using80mBr and82Br has been investigated for reaction with unsaturated lipids present in a fingerprint deposit. The reaction is rapid and
in combination with autoradiography provides a promising technique for the visualisation of latent fingerprints particularly
under conditions which preclude the application of other methods. Preliminary work on the degradation of fingerprint constituents
by UV and water is reported with comparative studies using the35SO2 reaction.
Epithermal Instrumental Neutron Activation Analysis has been used to measure the concentration of uranium in eutectic salt solutions in support of a research program in which the actinide elements are separated from rare earths and other fission products using high-temperature electo-deposition. The uranium response over three decades in concentration follows a negative power function; and high concentrations of samarium interfere with the determination of uranium but can be accurately corrected. The EINAA method was successfully used to analyze NIST SRM 278 Obsidian and NIST SRM 1566a Fly Ash.
Supplemental zinc as ZnO is routinely added to nursery pig diets at 15 to 20 times the nutritional requirement to alleviate
physiological stress and enhance performance. The mechanism by which Zn accomplishes this function is unknown, however, high
concentrations of Zn are excreted in the environment at undesirable levels. To study Zn uptake, we developed a multi-stage
digestion model followed by exposure to swine intestinal brush border membrane vesicles (BBMV). We report on the feasibility
of using a duel label (65Zn and 69mZn) to simultaneously quantify the competitive uptake of Zn from co-existing zinc supplements using our BBMV model.
A bench-scale method was developed to remove cobalt- and mercury-EDTA chelates from water onto macroporous char. Experimental parameters included variations on solution pH, char pre-treatment, cobalt oxidation state, and apparatus configuration. The use of 60Co and 203Hg radiotracers allowed for total accountability of the metals in the char and effluents. Overall experimental results demonstrate the applicability of treated macroporous chars for the effective removal of both cobalt and mercury EDTA chelates from aqueous solutions. The char system was optimized to sequester 97.5% and 99.8% of the cobalt- and mercury-EDTA from 20 ppm solutions, respectively.
Authors:J. Guthrie, J. Brockman, J. Morris, and J. Robertson
Numerous studies have demonstrated that the human toenail is a reliable biomonitor for the intake of Se and other elements.
The objective of this study was to evaluate the use of the toenail as a biomonitor for Mn. Toenail specimens from One Source™ multivitamin users and matched controls were selected. Se was measured using established NAA methods, then Mn was measured
via a new procedure. The Se results confirmed the accurate classification of the cohort. However, the nail did not show significant,
positive response to Mn supplementation. We hypothesize that the persistence of exogenous Mn confounded the results.
Authors:J. Colbert, R. Martin, S. Manahan, and J. Morris
A experimental method to measure the fate and distribution of a variety of radionuclides under the ChemChar gasification process
has been developed. The elements studied were arsenic, mercury, thorium, protactinium, uranium and neptunium. Results indicate
that the ChemChar gasification system quantitatively retains these elements. In all of the cases except mercury the radiotracer
was found to reside on the char matrix with small amounts (<1%) being found downstream in the condensation trap and char filter.
Mercury, presumably as vapor, was entrained and distributed in significant amounts (≈40%) to the downstream char filter and
its pre-filter. A methodology was developed to account for char height differences in quantifying the radiotracer on the char
prior and subsequent to gasification. These results demonstrate the efficacy of using relatively short-lived radiotracers
to characterize the behavior of hazardous elements during waste treatment via gasification.