The determination of manganese status in the Australian diet using neutron activation analysis

Fifty representative foods sampled Australia-wide from each of the State capitals were analysed for manganese by instrumental neutron activation analysis. Calculated daily intake of manganese for Australian diets was compared with recommendations by US authorities for the safe and adequate dietary intake of this essential trace element. The contribution of tea to adult daily intakes was determined.     

Selenium status in the blood of Australians using neutron activation analysis

Selenium determination by neutron activation analysis via both short and longlived selenium isotopes was performed on 98 samples of whole blood taken from Sydney workers. Half of the samples were further separated into their compenents and selenium measured on the erythrocyte and plasma fractions. The average selenium concentrations for blood, plasma and erythrocytes were 0.103, 0.091 and 0.117 g·ml^–1, respectively. These are compared with literature values for Australia and other countries.     

Trace elements in coloured opals using neutron activation analysis

Neutron activation analysis was used to determine the concentration of trace elements in 50 samples of orange, yellow, honey, green, blue and pink opals as well as 18 samples of colourless opals taken from a number of recognised fields in Australia, Peru, Mexico and USA. The results were evaluated to determine the relationship between trace element content and opal colour.     

Determination of iodine in milk products and biological standard reference materials by epithermal neutron activation analysis

The biologically essential trace element, iodine, has been determined in various milk products by epithermal neutron activation analysis /ENAA/ after sealing in quartz and irradiating under cadmium cover. The method was extended to several IAEA and NBS biological reference materials.     

Hyperresolving phase-only filters with an optically addressable liquid crystal spatial light modulator

Hyperresolving (sometimes called 'superresolving' or 'ultraresolving') phase-only filters can be generated using an optically addressable liquid crystal spatial light modulator. This approach avoids the problems of low efficiency, and coupling between amplitude and phase modulation, that arise when using conventional liquid crystal modulators. When addressed by a programmed light intensity distribution, it allows filters to be changed rapidly to modify the response of a system or permit the investigation of different filter designs. In this paper we present experimental hyperresolved images obtained using an optically addressable parallel-aligned nematic LCD with two zone Toraldo type phase-only filters. The images are compared with theoretical predictions.     

Rapid radiochemical separation in neutron activation analysis : Part 1. The use of C18-bonded silica gel and selective complexation for determinations of manganese,copper and zinc in biological materials

A rapid radiochemical separation method based on the removal of metal ions by columns of C₁₈-bonded silica gel after selective complexation by 8-quinolinol, ammonium pyrolidinedithiocarbamate or cupferron is described for the determination of manganese, copper and zinc in neutron-activated biological materials. The removal of the metal ions, either by adsorption or by a combination of filtration and adsorption on columns of C₁₈-bonded silica gel, was investigated to optimise the separation procedure. Analysis of several National Bureau of Standards and International Atomic Energy Agency biological reference materials demonstrated the effectiveness of this technique. The method is simple and reliable and readily adaptable in all radiochemical laboratories. Furthermore, columns of C₁₈-bonded silica gel have been successfully recycled a number of times without deterioration.     

A study using neutron activation analysis of the short-term changes in the selenium content of blood components in human following supplementation with low doses of selenium

A study was undertaken to evaluate the short-term changes in the concentration of selenium in whole blood, plasma and erythrocytes following supplementation with low doses of four different selenium supplements. Fourteen volunteers took one of the supplements each day with breakfast for a period of six weeks. Two blood samples were taken each week during this time and selenium was determined on its components using neutron activation analysis via the^77mSe isotope.     

Rapid determination of selenium in human serum by neutron activation analysis

A simple and rapid method was developed for the determination of selenium in human serum using a pre-irradiation separation technique of ultrafiltration followed by neutron activation analysis via the short-lived activation product^77mSe. The method was validated using certified reference material.