Determination uranium in solutions by the method of neutron activation analysis with 252Cf radionuclide neutron source

A determination option for 238U in solutions by the neutron activation analysis was investigated. A radionuclide treatment based on 252Cf was used as a neutron source. The limit for the determination of uranium using thermal neutrons of 0.1 mg L-1 was determined within the research framework. With the help of preliminary concentration of the sample via the evaporation method, it is possible to further reduce the detection limit by 2-5 times. It is defined that the optimal time for measuring the induced activity of the sample, when working with a short-life isotope of 239U, is 30 min. The influence of the effects of scattering and self-absorption of gamma radiation of the uranium line 74.6 keV on the results of the neutron activation analysis is determined. The studies conducted made it possible to determine uranium by the neutron activation analysis method in solutions of various compositions, in a wide range of concentrations.

Evaluation of the factor of enrichment of atmospheric particulate matter in the Campus of UFMG, Belo Horizonte

The particulate matter present in the atmospheric air of large cities is one of the pollutants that causes great environmental risks. Due to their composition of solids and liquids varying in size, shape, composition and origin, they have an impact on the health of the exposed population, agriculture, forests and acidification of lakes. In this scenario, the present work had as objective to evaluate the concentration of the 10-micrometer particulate matter, commonly called PM10, and the elementary concentrations in air filters whose sampling was carried out at the Campus of the Federal University of Minas Gerais. For this, a high-volume sampler was used to collect the particulate matter. The elementary concentration of the particulate matter was determined via neutron activation analysis, method k0. Applying the enrichment factor technique, the influence of anthropogenic sources at the sampled site was investigated. The results showed anthropogenic interferences of zinc, sodium, chromium and iron and a geogenic impoverishment of cobalt.

Determination of selenium in roasted beans coffee samples consumed in Algeria by radiochemical neutron activation analysis method

The essential trace element selenium is a focus of attention due to its effects on human health, there being consequences of both its deficiency and excess. Due to the ultra-trace content of selenium, the neutron activation analysis method (NAA) is difficult to apply. We therefore made use of the radiochemical neutron activation analysis (RNAA) to determine Se at low level concentrations in several consumed food items in Algeria. A radiochemical procedure based on liquid–liquid separation was established in our laboratory. In this research we focused on the determination of selenium in two species of coffee: Arabica and Robusta. The accuracy of the method was assessed by analyzing the certified reference material NIST-SRM 1573a (tomato leaves). The results obtained show a selenium variation from 0.025 to 0.052 μg/g in coffee beans and an average yield of the separation of about 85%. The results of this study were compared with those obtained with samples from Brazilian, Caribbean, Indian and Kenyan coffee beans.

ANALYSIS OF MACRO AND MICROELEMENTS IN TEETH, SALIVA, AND BLOOD OF WORKERS IN FERGANA CHEMICAL PLANT OF FURAN COMPOUNDS

This article aims to share the results of research conducted in the Fergana chemical plant of furan compounds (FCPFC) in Uzbekistan.19 workers of the Furan compounds plant, in Fergana, Uzbekistan, were tested. By neutron activation analysis method, we have studied microelement composition of saliva, blood, dental hard tissue, and the level of Ca, Zn, Fe, and Ag in these subjects. We havedetected that the level of chemical elements in dental hard tissue, blood, and saliva of these workers was subject to negative changes as compared to the analysis results from those in the control group.The research results havepractical value for the prophylaxis, treatment, and health resumption of the people living in rugged ecological environment and workers who are engagedwith harmful substances in chemical industry. Furthermore,this research also provides recommendations fortreatment of dental diseases related to common conditions of pathophysiological processes carried out bylivingorganisms.