Determination of trace elements in hepatocyte of zinc deficient mice by means of INAA

Eleven elements in hepatocyte of mice fed with zinc deficient diet and those fed with control diet were determined by INAA. Zinc concentration, especially, in cytosolic fraction of zinc deficient mice was lower than that of control ones. On the other hand, cobalt concentrations in all fractions of zinc deficient mice were higher than those of control ones. However, when SDS-PAGE was performed for cytosolic fraction of hepatic cells, the positions and the number of the protein bands on gel developed for zinc deficient mice were not different from those for control ones.     

Uptakes of trace elements in Zn-deficient mice

A multitracer technique was used to obtain uptake rates of essential trace elements in various organs and tissues in Zn-deficient mice. A multitracer solution, containing more than 20 radioisotopes, was injected intraperitoneally into Zn-deficient state mice and control ones. Uptake rates of the radioisotopes were compared with concentrations of trace elements determined by instrumental neutron activation analysis (INAA) in order to study a specific metabolism of Zn and other essential trace elements, such as Mn, Co, Se, Rb, and Sr. The result suggests that Zn is supplied from bone to other organs and tissues and an increase in Co concentration in all organs and tissues depends on its chemical form, under the Z-deficient state.     

Frequency of concentrations of some trace elements in serum by INAA

Concentration levels of eight trace elements in 120 samples of human blood serum were investigated by Instrumental Neutron Activation Analysis (INAA) for the purpose of medical research. The elements Co, Cr, Cs, Fe, Rb, Sc, Se, and Zn were simultaneously determined by the relative method in comparison with inorganic standards treated under identical conditions. The process of analysis and its reliability was checked using human serum and IAEA certified reference material. Statistical results are expressed in ppm or ppb. Both normal and, if necessary, log-normal frequency distributions of all elements determined are presented, types of distribution curves are verified statistically on 95% level of probability.     

Distribution of major and trace elements concentrations in gold processing using EDXRF

Studies have been carried out on the distribution of major and trace elements concentrations in oxide and sulphide feed ores at various stages of milling and processing of gold in a goldmine at Bogoso in the western region of Ghana. The studies evaluated concentration enhancements at various stages of treatment with emphasis on understanding the typical processes leading to enhancement of concentration at each stage and ultimately the impact from discharges into the surrounding environment. The feed ore samples were analyzed using energy dispersive X-ray fluorescence spectrometry. The results show concentration enhancements of a significant number of elements at some stages of processing in the two processing plants with the highest number of elements with enhanced concentrations coming from chemically treated media of both plants. Though there are relatively high concentrations of V (max.: 284 ppm), Cr (max.: 149 ppm), Co (max.: 84 ppm), and U (max.: 26.8 ppm) at the discharge points, the concentrations of most of the toxic elements in the slurries discharged into the tailings dam are mostly within their respective world averages. The enrichment indices computed for the slurries being discharged into the tailings dam suggests that the dam is not enriched with the toxic elements Cr, Co, Ni, Zn, Cu and Pb. The enrichment index of the slurries discharged into the tailings dam decreases in the order of oxide plant > sulphide plant. Principal component analyses performed suggest that Al₂O₃, K₂O, Co, Zn, Cu, Y and Zr are geochemically associated. Results from the studies also suggest that the discharge of these elements into the tailings dam may contribute insignificant pollution of the surrounding area.     

Determination of the concentrations of trace and doping elements in GaAs by neutron activation analysis

The concentrations of ten trace and dopant elements in GaAs semiconductor were determined by reactor neutron activation analysis after removal of As by evaporation of AsCl₃. The retentions of the elements of interest were measured using radiotracers. The concentrations of doping elements (Te, Cr and Zn) in commercial GaAs samples were compared to the limit of detection of these elements to analyze the possibility to use NAA for concentration depth profiling measurements. The NAA results were compared with those of electrical measurements and SIMS and the discrepancies found are discussed.     

Frequency of concentrations of some trace elements in scalp hair by INAA

126 samples of scalp hair from inhabitants of Central Bohemia were searched for content of zinc, cobalt, cesium, chromium, scandium, selenium, and iron, for the purpose of medical research. Simultaneous determination of the elements was made by INAA. Inorganic standards were used for calculation of concentrations of elements. Quality assurance was checked by IAEA certified reference material and by internal standard mixed human serum. Statistical results are expressed in ppm, or ppb. Both normal and, if necessary, log-normal distributions of elements are presented, and types of distribution curves are verified statistically on 95% level of probability.     

Biomonitoring of trace elements in muscle and liver tissue of freshwater fish

The aim of this study was to investigate the potential impact of a coal combustion power plant in the northern part of Vietnam with regard to elemental pollution on the surrounding environment. Freshwater fishes (Clarias fucus) were sampled both at a site exposed to the emissions of the power plant and at a reference site seemingly free from industrial activities. The elemental concentrations in muscle and liver tissue were analyzed using total-reflection X-ray fluorescence and atomic absorption spectroscopy. A comparison of muscle tissue with International Standards (Food and Agricultural Organization) showed that the fishes from both sites did not constitute any health risk for human consumers with regard to the elements Cu, Zn, As, Se, Cd, Pb and Cr. Generally, concentration differences between sites were found to be small in the edible tissue. Compared to the muscle tissue, concentrations of metals were elevated in the liver. The elemental concentrations of P, S, K, Ca, Fe, Mn, Zn and Pb were significantly higher in the hepatic tissue from the exposed site, suggesting—together with measurements of airborne pollutants—emissions from the power plant as a probable source of these elements.     

Evaluation of concentrations of major and trace elements in human lung using INAA and PIXE

The elemental concentrations of Br, Ca, Ce, Cl, Co, Cr, Cs, F, Fe, Hf, K, Mg, Mn, Na, O, Rb, Sb, Sc, Se, V and Zn in 15 human lung autopsy samples, taken from subjects aged more than fifty years old, were determined by instrumental neutron activation analysis (INAA) using reactor neutrons in conjunction with a high resolution detection system. Two modes of irradiation and counting were applied; namely cyclic neutron activation analysis (CNAA) and conventional neutron activation analysis. Proton induced X-ray emission (PIXE) analysis, using a proton beam emerging from a 2 MV Van de Graff accelerator, was additionally employed and Ge, Ni, P and Ti were also identified in the lung tissue. Detection of the X-ray spectra was performed using a high resolution Si(Li) semiconductor. The relevance of these results, including a comparison between the concentrations of elements measured in a pig's lung using CNAA and those found in the human lung is discussed.     

Distributon of trace elements in organs of mice of different inbred strains

In eight organ systems of five different inbred strains of mice the concentrations of rubidium, zinc and iron were investigated. In the case of rubidium two of the inbred strains showed relatively low concentrations in all organ systems, whereas zinc and iron exhibited a rather irregular distribution within the eight organ systems. The differences in concentrations found in the various organs of the five inbred strains—especially the distribution pattern of rubidium—may allow further genetic experiments and thus help to elucidate the physiology and pathology of trace elements.     

Determination of trace elements in wool fibre by instrumental neutron activation analysis and relation between trace element contents and quality of wool

Synergistic extraction of uranyl ion with 2-thenoyltrifluoroacetone (HTTA) and aliphatic amides with varying basicities, viz. dibutyl hexanamide (DBHA), dibutyloctanamide (DBOA) or dibutyldecanamide (DBDA) has been studied at various fixed temperatures of 20, 30, 40 and 50±0.1°C. Results indicate that the equilibrium constants of the organic phase addition reaction (Ks) with these amides follow their order of basicity (Kh) viz. DBHA (0.09)<0.10) H DBOA (0.13) with log Ks values of 4.91, 4.99 and 5.02, respectively. These values are much higher than those with TBP (3.8) or sulfoxides (4) as donors. This may be attributed to the existence of a resonance form of the amide, which has higher electron density on the carbonyl oxygen. The thermodynamic parameters associated with these systems evaluated by the temperature coefficient method indicate that the organic phase addition reaction with all the three amides is stabilized by both enthalpy and entropy changes as against UO ₂ ²⁺ /HTTA/TBP system, where only the enthalpy change contributes to the stabilization.     

Adsorptive stripping voltammetry of some trace elements in biological samples. I. Cadmium and zinc

A study of the adsorptive stripping voltammetry of cadmium and zinc is reported in which ligands containing sulphur donor atoms were examined. This type of ligand showed good adsorptive behaviour and strong metal complexation. It was found that the ligand 2,5-dimer-capto-1,3,4-thiadiazole (DMTD) was very suitable for the determination of cadmium and zinc using this technique.The method was applied to the direct determination of these metals in biological samples using benzyl trimethylammonium methoxide as digesting solvent for the samples.     

Study on the contents of trace rare earth elements and their distribution in wheat and rice samples by RNAA

The concentrations of 8 REE (La, Ce, Nd, Sm, Eu, Tb, Yb and Lu) in wheat and rice samples have been determined by RNAA. The contents and distributions of REE in each part of the plants (i.e. root, leaf, stem, husk and seed) and their host soils were studied, which included samples applied with rare earch elements in farming and control samples. The effects of applying rare earths on the uptake of REE by the plants and the REE accumulation in the grains on human health were also discussed in this paper.     

原油中微量金属元素的测定及风化条件下元素的变化规律

建立了微波消解-电感耦舍等离子体质谱(ICP.MS)法同时测定原油及自然风化后原油中的V、Cr、Mn、Fe、Ni、zn、Mo、Ba等11种微量金属元素的方法.结果表明,11种微量金属元素的检出限为0.0056～0.8729μg/g,线性关系良好,相关系数r≥0.9995;相对标准偏差(RSD)<5.0%.经过30d风化...     

Determination of protein and trace elements in human milk using NAA and XFR techniques

The principal objective pursued in this study is to establish the base-line data on protein content and on the status of elemental composition in human milk from Sudanese subjects. The protein content was derived by multiplying the nitrogen content by a factor 6.25. The nitrogen was determined using a 14 MeV neutron generator. The median values for crude protein and the total dry matter found in this study were 1.23% (volume) and 104 g/l, respectively. Some minor and trace elements of biological significance namely, Cl, K, Ca, Mn, Fe, Cu, Zn, Cr, Co and Mo were determined using energy dispersive X-ray fluorescence spectrometry. The results obtained show good compatibility with the data reported by the WHO on elemental composition of human milk from different geographical regions.     

Global status of trace elements in the ocean

Trace elements in seawater can be limiting factors of biological productivity, tracers of ocean circulation and biogeochemical processes, and proxies for paleoceanography. The global status of trace elements and their isotopes (TEIs) in the ocean is being explored this decade through an international study of the global marine biogeochemical cycles of TEIs (GEOTRACES). Such an international study has become possible due to recent methodological developments in sampling, preconcentration, and measurement of TEIs. Here, we present an overview of recent methodological developments and initial GEOTRACES intercalibration activities for obtaining data about TEIs that are accurate, precise, and intercomparable.     

Determination of low concentrations of potentially toxic elements in human liver from newborns and infants

One hundred and fifty-seven liver samples from newborns and infants who had died from sudden infant death syndrome (SIDS) or other known causes have been analysed by ICP-MS for Ag, Cd, Co, Pb and Sb. The median concentrations found were: 15.4 (Ag), 2.9 (Cd), 15.9 (Co), 65.2 (Pb) and 1.8 (Sb) ng g-1 wet mass. There was no measurable difference in the concentrations of any of these elements between the SIDS and non-SIDS groups. The validity of the results was assessed by analysis of appropriate reference materials, interlaboratory comparison and isotope dilution analysis. The instrumental limits of detection were 0.25 (Ag), 0.14 (Cd), 0.21 (Co), 3.8 (Pb) and 0.38 (Sb) ng g-1 wet mass. The limits of detection of the method depend on the reagent blank and the extent of background contamination.     

Polyurethane-pyridylazonaphthol foams in the preconcentration and separation of trace elements

The feasibility of using PAN—polyether and polyester polyurethane foams in batch and column operations has been examined. The effects of pH, plasticizer and various anions present in the aqueous solution on the extraction behaviour of cobalt, iron and manganese have been investigated. In dynamic systems, the effect of flow rate on the extraction efficiencies of these metal ions has been investigated. The uptake of cobalt(III) and manganese(II) on PAN—polyester foam columns is quantitative at flow rates up to 10 ml min^-1 and 2 ml min^-1, respectively. The retention of iron(III) by the foam column is not quantitative even at a flow rate of 1 ml min^-1. Preconcentration of cobalt and its separation from various concentrations of manganese are successful..     

On the distribution of trace elements in human skeletons

Instrumental neutron activation analysis and flameless atomic absorption spectrometry have been used to study the occurence and distribution with a maximum of 25 elements in multiple sites of a skeleton and in the iliac crest of 69 ancient human skeletons. To study the distribution of trace elements between the different bone fractions the material of each sampling site was chemically treated to separate the collagen and the mineral from one another. Losses or contamination during the extraction procedure have been controled in detail by balance calculations. The elements can be subdivided into several groups due to the balance calculation and their association with the mineral. The analysis of the skeleton showed that the trace elements are distributed in varying degrees within a bone and throughout the skeleton their variation seems to be related to functional and structural conditions of the sampling site. The element content was observed to be higher at epiphyseal areas of long bones than in the shaft and higher in trabecular than in cortical bones. It was found that the element content of a single bone sample depends largely on the mass ratio spongiosa/compacta at the sampling site. By investigating an ancient population group, information about the “natural levels” and biological variation of trace elements was obtained. The results for F, Pb, Sr, and Zn in particular suggest that these elements could be useful in the study of health problems in man which involves the bone tissue.