Neutron activation analysis of trace elements in cataracts

The knowledge of the role of trace elements is a necessary condition for the investigation of cataract etiopathogenesis. The deposition of trace elements in eye lens may be influenced by many vital factors and, therefore, the effect of sex, age and locality on the content of these elements was investigated. The determinations of elements were carried out by instrumental neutron activation analysis, and the results were evaluated with the aid of statistical tests. The effect of locality being taken as a set of local ecological factors has been proved as a dominant factor.     

Neutron activation analysis for trace elements in foods

Food samples reflecting average food consumption by an adult in the southeastern, northeastern, central, and western parts of the United States were collected and prepared as if for consumption. The prepared foods were divided into twelve different food categories and analyzed by instrumental neutron activation analysis. The concentration of Ca, Mn, Mg, Al, Na, K, Cu, Cl, Sb, Hg, Se, Fe, Zn and Co is reported for these food samples.     

Neutron activation analysis of trace elements in Japanese hormesis cosmetics

In Japan, cosmetics claiming hormesis effect are available through Internet. Although these cosmetics show the contents, they never mention the minor elements and radioactive sources. The existence of radioisotopes, however, was observed by measurements of the gamma-rays with a HPGe detector. In this study, in order to clarify the contents of trace elements, the hormesis cosmetics including radioactive sources were analyzed using INAA, PGAA and NAA with multiple gamma-ray detection (NAAMG). Nineteen elements were analyzed quantitatively in hormesis cosmetics by INAA, PGAA and NAAMG and 16 elements were detected qualitatively by SEM-EPMA.     

Determination of trace elements in petroleum by neutron activation analysis

Instrumental neutron activation analysis (INAA) and Ge(Li) spectrometry have been used to determine Sc, Cr, Fe, Co, Ni, Zn, As, Se, Sb, Eu, Au, Hg, and U in crude petroleum. The technique involves no chemical separations and no pre-concentration of the samples by ashing is necessary, thus avoiding contamination or loss of volatile elements. The estimated detection limits in ppb for the elements are Sc (0.1), Cr (0.16), Fe (400.0), Co (0.6), Ni (1.1), Zn (200.0), As (6.0), Se (23.0), Sb (1.0), Eu (0.58), Au (0.11), Hg (4.3), U (1.5). Precision values ranged from 0.1% to 15% (relative standard deviation). Interferences in the Co and Fe determinations due to fast neutron reactions (n, p) and (n, α) on Ni isotopes are small and are easily corrected. Losses of As, Se, and Hg due to escape of volatile gases during irradiation are negligible     

Determination of trace elements in petroleum by neutron activation analysis

Using thermal neutron activation and a large-volume high-resolution Ge(Li) γ-ray spectrometer, the feasibility of the determination of the concentrations of Na, S, Cl, K, Ca, V, Mn, Cu, Ga, and Br in crude oils has been demonstrated. This instrumental method, which requires neither a chemical separation technique nor pre-concentration or post-concentration of trace elements by ashing, eliminates many inherent errors associated with chemical determination. The method is sensitive, precise and suitable for routine analysis. Fast neutron (n, p) and (n, α) reactions do not appreciably interfere and where necessary corrections may be applied. Loss of volatile elements, e.g. chlorine and bromine, due to recoil during irradiation is negligible.     

Neutron activation analysis for bulk and trace elements in urine.

Problems in sampling urine for trace element analysis by neutron activation are systematically examined. Collection, storage, sample preparation and contamination hazards during irradiation are studied in detail. Three different sizes of urine samples are prepared for analysis, depending on the concentration and nuclear properties of the elements, and suitable multielement doped urine standards are used. As, Br, Ca, Cl, Co, Cr, Cs, Cu, Hg, I, K, Mg, Mn, Na, Rb, Sc and Zn are determined. The extreme care given to sample collection, use of “ultra-clean” vials, and work in a dust-free room, allows consistent values to be obtained over long periods of time. A literature review of the amounts of forty elements present in urine per day is also given.     

Neutron activation analysis of 13 minor and trace elements in geological samples

A scheme of analysis for the determination of Na, Mn, U, Th, Hf, Sc, La, Ce, Eu, Tb, Co, Rb and Cs in geological samples using the neutron activation technique has been described. The results obtained in this work on eight geological standard rocks and a trachyte are presented and compared with literature data.     

Determination of major and trace elements in crude oils by neutron activation and reflection methods

The concentrations of O, Na, Cl, V, Mn and Ni in crude oils of different origins were determined, using sampling (SNAA) and on-stream (ONAA) activation analyses. Samples were irradiated with thermal and fast neutrons produced by a 0.3 mg²⁵²Cf source and a 14 MeV generator. The H-content and the C/H atomic ratio have been determined by thermal neutron reflection method using an 18 GBq Pu−Be source. This work was supported in part by the Hungarian Academy of Sciences.     

Neutron activation studies of trace elements in tree rings

The levels of twelve elements most of which are either considered essential to plant growth or have been detected in air filter samples in an air pollution survey, have been monitored in three transverse sections of trees, two elms (ring porous trees) and one cedar (a conifer). Two dimensional distributions of these elements around the tree rings of the section and radially from ring to ring, have been obtained to see if tree rings can be analysed for use as a record of historical pollution.     

Neutron activation analysis of some of the biologically active trace elements in fish

Highly specific neutron activation analysis procedures involving post irradiation chemical separations were developed for the determination of Cu, Hg, Zn, Cd, As, Se and Cr in fish tissues. The procedures developed were used to determine the levels of these biologically active elements in some of the commercially important fish species of Lake Erie. The nuclear analytical procedures developed generally involved the irradiation of fish tissues followed by wet-ashing in the presence of nonradioactive carriers From the homogeneous solution of the tissue digest, the elements of interest were chemically isolated and the radio-activities were measured by scintillation gamma ray spectrometry. The results reported include both the determination of the precision and accuracies of each of these elemental analyses and a survey of these seven elements in nine major fish species of Lake Erie.     

Neutron activation analysis of Nigerian crude oils

Since the advent of the Nuclear Age mankind has been both fascinated by the potential of nuclear processes, and fearful of its destructive power. Nuclear technologies have undergone rapid development, while most of society is left with a poor understanding about the benefits and risks involved. Our Nuclear Society: from Chemobyl to PET Scans, and Energy, Technology and Risk are two courses developed at the University of Maryland in an effort to introduce students from all backgrounds to issues and applications of nuclear science. Course material and presentation strategies are geared toward keeping the course interesting and informative for all students.     

Neutron activation analysis of biologically essential trace elements in environmental specimens using pyrrolidinedithiocarbamate extraction

A new radiochemical group separation method using APDC reagent in the extraction procedure has been developed. The method has been applied to the radiochemical separation for activated biological samples and also to the preconcentration technique for sea water samples. The transition elements are extracted into chloroform phase from the pH 3.0 aqueous phase and only manganese is subsequently extracted from the pH 7.0 aqueous phase. The validity of the method is demonstrated by analyzing the NBS standard reference materials. In the specimens preconcentrated from the sea water samples adjusted pH to 5.5, vanadium, manganese, copper and zinc can be determined.     

Neutron activation analysis of trace elements in sea water samples (author's transl)

Analytical values of trace elements in sea water samples have been fluctuated according to the sampling locations, the analytical procedures and so on. It is very important in marine chemistry to elucidate the cause of such concentration variations. This report is the analytical results of the samples obtained in the Pacific Ocean, the Indian Ocean and the Sea of Japan, by means of neutron activation analysis. As the preconcentration, APDC-chelate extraction and freeze-drying were adopted. The specimens obtained by this extraction from 500 or 800 ml samples were irradiated by KUR reactor for 1 min, 1 hr to 10 hrs and the gamma-ray spectrometry with a Ge(Li) detector was used for the determination of V, Mn, Cu, Zn, U, Fe, Co, Ni, Ag, Sb and Au. By about 80 hrs irradiation of the specimens obtained by freeze-drying from 20 ml samples and their gamma-ray spectrometry, Sc, Cr, Fe, Co, Zn, Rb, Sr, Ag, Sb and Cs were determined. The former procedure gives concentrations of elements in species reactable with APDC, but the latter method shows entire concentrations of the elements in the sea water samples. Some considerations on the analytical values and the comparisons of the both methods are described.     

Neutron activation analysis of trace elements at sediment-water interface in the Biwa Lake, Japan

Concentrations of eighteen trace elements at the sediment-water interface in Biwa Lake were determined by neutron activation analysis. Release of iron, manganese and arsenic from the sediment to the pore water was observed under anoxic conditions. The concentrations of Sb in the pore water as well as Na were nearly constant between the surface and the depth of 40 cm. The behavior of Sb differed from that of As at the sediment-water interface, since the partition coefficient of Sb differed from that of As.     

Determination and geochemical significance of trace elements in Iraqi crude oils using instrumental neutron activation analysis

The trace-element composition of crude oil was studied using instrumental neutron activation techniques and a large-volume high-resolution Ge(Li) detector. A total of 29 elements were determined in oils representing the various producing formations of the Iraqi oil fields. These were: Al, Ar, As, Au, Br, Ca, Cl, Co, Cr, Cu, Eu, Fe, Ga, Hg, K, La, Mn, Mo, Na, Ni, Re, S, Sb, Sc, Se, Sm, V, W and Zn. The significance of these trace elements in the geochemical investigation of crude oil is discussed.     

Determination of major components and trace elements in ancient silver by thermal neutron activation analysis

Thermal neutron activation of minute samples of ancient silver objects has provided useful information concerning their silver, copper and gold content. The results of such analysis of eighteen Sasanian silver objects are discussed together with consideration of the sampling problems involved. In order to extend these measurements to include other elements, an isotopic exchange system has been developed to separate other activities present in irradiated silver specimens quantitatively from the silver, copper and gold activities. Following exchange with cuprous and silver iodides it has been possible to count quantitatively the activity of fourteen additional elements: As, Br, Co, Cr, Fe, Hg, Ir, K, Mn, Na, Sb, Sc, Se and Zn. Research supported in part by the U. S. Atomic Energy Commission.     

Neutron activation analysis for determination of trace elements in sediments in the Sea of Galilee,Israel

The feasibility of applying both thermal and epithermal neutron activation analysis for simultaneous determinations of elemental composition in sediments, collected from the Sea of Galilee (Kineret Lake), Israel, during 1988–1993, was experimentally investigated. In the present work, the concentrations of 30 elements (Al, Ba, Br, Ca, Ce, Co, Cs, Cr, Eu, Fe, Hf, K, La, Lu, Mg, Mn, Na, Nd, Rb, Sc, Si, Sr, Ta, Tb, Th, Ti, U, V, Yb and Zn) in sediments were determined. The validity of the method was checked by analyzing the U.S. NBS Standard Reference Material SRM-1633a; the elemental content found agreed well with the published certified data. Aluminium was determined by reactor neutron activation analysis (RNAA) taking into account the contribution of silicon to the total²⁸Al activity by the²⁸Si(n,p)²⁸Al reaction. Measurements of irradiated mixtures of Si and Al showed that the dependence of log SiAl mass ratio vs. log cadmium ratio (R _Cd) of²⁸Al is almost linear. The data can be analyzed more accurately by a parabolic correlation (log Si:Al mass ratio vs logR _Cd). The concentrations of fission radionuclide¹³⁷Cs, an activation radionuclide¹³⁴Cs (derived from Chernobyl accident) and the naturally occuring radionuclides⁴⁰K,²²⁶Ra and²³²Th in sediments were also measured by -ray spectrometry using Marinelli (Reentrant) Beaker-Sample Containers.     

Neutron activation analysis applied in sediment samples from the Guarapiranga Reservoir for metals and trace elements assessment

The Guarapiranga Reservoir is a very important aquatic system due to the fact that it is one of the main water reservoirs for South America’s largest city, São Paulo, Brazil. Guarapiranga basin is located within the Metropolitan Region of São Paulo and the reservoir itself is located in the Northern part of the basin occupying approximately 26 km². This reservoir is characterized by environmental impacts from urban invasion, industrial and sewage wastes, all of which seriously affect its water quality and, consequently, the sediment quality. Two collection campaigns were undertaken: April 2009 and June 2010. The samples were analyzed by instrumental neutron activation analysis (INAA) in order to determine the following elements: major (Fe, K and Na), trace (As, Ba, Br, Co, Cr, Cs, Hf, Rb, Sb, Sc, Ta, Tb, Th, U and Zn) and rare earths (Ce, Eu, La, Lu, Nd, Sm, Tb and Yb). The organic matter and granulometric distribution were also evaluated and multivariate analysis was applied to the results. The study of elemental ratios indicated that the amount of elements present in the Guarapiranga Reservoir is mainly of detrital origin.     

Neutron activation analysis of selenium and 17 elements in sediment.

Instrumental neutron activation analysis was performed to determine Na, Mg, Al, Cl, Sc, V, Cr, Mn, Fe, Co, Ni, Rb, Sb, Cs, Ba, Ce and Eu in the Pacific core sediment. Selenium was also determined by neutron activation analysis, by applying a solvent extraction method with 2,3-diaminonaphthalene (DAN) as a post-irradiation procedure, after the wet-ashing of the sediment. Homogeneity of trace constituents in the sediment and neutron flux corrections for accurate determination were also investigated.