K0-instrumental Neutron Activation Analysis Research Articles

Investigation of MoS2 by k0 instrumental neutron activation analysis and electronic paramagnetic resonance

Investigation of MoS2 by k0 instrumental neutron activation analysis and electronic paramagnetic resonance

Evaluation of peak-fitting software for magnesium quantification through k0-instrumental neutron activation analysis

The selection and effective utilization of peak-fitting software for conventional gamma-ray spectrum analysis is significant for accurate determination of the mass fraction of elements, particularly in complex peak regions. Majority of the peak-fitting programs can derive similar peak characteristics for singlet peaks, but very few programs can deconvolute multi-peaks in a complex region. The deconvolution of multi-peaks requires special peak-fitting functions, such as left and right-skew distributions. In the this study, 843.76 keV (27Mg) peak area from the complex region (840 keV–850 keV) determined and compared using four different peak-fitting programs, namely, GammaVision, Genie2000, HyperLab, and HyperGam. The 843.76 keV peak interfered with 841.63 keV (152mEu) and 846.81 keV (56Mn). The total Mg concentration was determined through k0-instrumental neutron activation analysis by applying the isotopic interference correction factor 27Al(n,p)27Mg through the simultaneous determination of Al concentration. HyperLab and HyperGam peak-fitting programs reported consistent peak areas, and resultant concentrations agreed with the certified values of matrix-certified reference materials.

The low enriched uranium miniature neutron source reactor (LEU-MNSR) neutron spectrum characterization for k0-INAA

Ghana’s highly enriched uranium (90.2%) research reactor has been converted to a low enriched uranium (13.0%) type. Its neutron parameters have been characterized for the application of k0-instrumental neutron activation analysis. The magnitude of the LEU epithermal neutron shaping factor (α) at the irradiation site increased by about 25% as compared to the HEU, while the thermal neutrons decreased by about 5%. This indicates that the epithermal neutron spectrum is much dependent on the 1/E1+α. Similarly, the measured fast neutron flux increased by about 22%. Generally, the results show that the LEU core’s neutron spectrum is relatively harder, i.e., there is a marginal increase in high-energy neutrons. The reactor spectrum parameters have been used to validate the k0-IAEA software. Two certified reference materials (Carbonate rock GBW 07108 (GBW2) and NIST Standard Reference Material 1646a, Estuarine Sediment (EST)) and the synthetic multi-element standard (SMELS I, II & III) were analyzed based on a routine irradiation scheme. The process quality assurance was evaluated based on a u-score test. Most (80 %) of the elements determined were within |u-score| < 1.64, while a few were observed within 1.964 > |u-score| > 1.64. The results show a suitable characterization process and the general applicability of the k0-IAEA software.

Recent changes in major and trace elements in sediments from a remote mountain lake (6th Triglav Lake) in the Julian Alps, NW Slovenia

We collected a sediment core from the 6th (6J) Triglav Lake, a remote mountain lake in NW Slovenia, and analysed it for 25 elements, using k0-instrumental neutron activation analysis (k0-INAA). For Hg, we used cold vapour atomic absorption spectrometry (CVAAS). Data were analysed using Principal Component Analysis (PCA). PCA indicated several distinct groups of elements and sediment core samples. Ca distribution was entirely different from all other sediment components. Ba, Br, Hg, Sb and Zn were associated with organic matter (OM), with Hg showing the strongest affinity to OM. As, Cr, Fe and U formed a group of redox-sensitive elements. Two events that occurred ca. 1915 and in the 1940s/1950s, were identified in the core. They were associated with increased inputs of allochthonous material into the lake, and significantly affected the stratigraphic distributions of all elements. Some trace elements, such as As, Hg and Zn, are probably effectively retained in the catchment, whereas Cr tends to be readily exported from the catchment. Atmospheric deposition affected not only elements of anthropogenic origin (As, Ba, Br, Hg, Sb, Zn and Cr) that started to increase after the 1970s, but also those of terrestrial origin (Ca, Fe, Na). Introduction of fish into the lake in 1991 and the subsequent increase in primary production, affected the distribution of Ca and elements that are redox-sensitive and/or associated with OM (As, Ba, Fe, Sb, U, Zn). Fe minerals in uppermost 6J sediments have a strong influence on the distribution of several trace elements. As and Zn closely tracked Fe, whereas Sb was likely released after oxidation. Climate change could also have enhanced inputs of elements from the catchment, but such changes were likely overwhelmed by the effects of increased eutrophication.

Elemental analysis of SRM 1547 peach leaves, 1573a tomato leaves, and 1570a spinach leaves

Neutron Activation Analysis Techniques more used in determining macro and microcontent in food ingredients. The quality of the test results is needed to produce a valid analysis. To validate the result of the analysis of macro and micro mineral content in food ingredients, quantitative analysis of the elements in the reference standard is NIST SRM 1547 certified Peach Leaves, NIST SRM 1573a Tomato Leaves, and NIST SRM 1570a Spinach Leaves have been done. The Z-score parameter was used as a validation parameter. Elemental with a long half-life was determined quantitatively using the NAA k0 method. The elements were determined quantitatively through long-lived radioisotopes using the k0 Instrumental Neutron Activation Analysis in the G.A Siwabessy reactor. A number of 50 mg-120 mg samples were weighed and irradiated at the neutron flux of 2.5x1013 n.cm−2.s−1. Irradiation was carried out for 3 hours on the rabbit system while counting with gamma spectrometry was carried out after cooling time of 23 weeks. Quantitative analysis was carried out using a soft K0-IAEA device. The results of quantitative analysis obtained elements of Ca, Fe, Zn, Rb, Sr on SRM NIST 1547 Peach Leaves; elements of Ca, Cr, Fe, Co on NIST SRM 1573a Tomato leaves and elements Ca, Sc, Zn, Rb, Sr, Co on NIST SRM 1570a Spinach Leaves with uncertainty <10% (3.26-8.68%). The Z-score value ranges from-1.25 to 0.69 and the relative bias ranges from 0.1 to 6.28%, so the results of the analysis of these elements are valid for testing elements in food.

Characterization and differentiation of iron ores using X-ray diffractometry, k0 instrumental neutron activation analysis and inductively coupled plasma optical emission spectrometry

This study was aimed at developing methodology for the characterization and differentiation of iron ores from different ore deposits. X-ray diffractometry (XRD) was used for the determination of major and minor chemical phases in the ores, k0-instrumental neutron activation analysis (k0-INAA) and inductively coupled plasma optical emission spectrometry (ICP-OES) were employed for the determination of elemental profiles of iron ores. The quality of the ores was evaluated to establish their suitability to serve as a raw material for iron production. Principal component analysis was performed on the elemental data for the classification of ores. It was also shown that ores can be differentiated on the basis of rare earth elemental profiles. In this paper a new indicator, based on four elements (Ca, S, Sb, Yb), was proposed for the classification.

Development of a method for the elemental analysis of milk powders using laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) and its potential use in geographic sourcing

Milk has been reported as one of the most adulterated foodstuffs in the developed and developing world. One way to detect adulteration is to determine whether the country of origin on the label could be the actual country of origin. Such profiling may be accomplished through the use of elemental analysis techniques, however this is a preliminary study and this goal is not yet met. In this study, a laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) method was developed for the analysis of solid milk powder and compared to k0-instrumental neutron activation analysis (k0-INAA) for a reference milk material (IAEA-153) as well as several milk samples from different countries. The analytical figures of merit for both the LA-ICP-MS and the k0-INAA analysis are reported. Precision of ~ 10% RSD or better was achieved for most elements for both techniques and bias of ~ 10% was achieved for both techniques for most elements with LA-ICP-MS producing lower limits of detection (~ 1 mg/kg) for Sr. The comparison of LA-ICP-MS to k0-INAA showed overlap of the 95% confidence intervals for all comparison samples. A total of 68 authentic milk powder samples representing 5 different countries (Argentina, Russia, Singapore, Slovenia, and the United States) were analyzed to determine whether multivariate elemental differences between the countries were sufficiently larger than within country differences in order to visualize groupings by country. Principle component analysis (PCA) using Na, Mg, Ca, Rb, and Sr show different groups for the United States, Argentina, Singapore, and Slovenia samples of limited representation for each country. However the large number and geographic distribution of samples from Russia were not able to be distinguished from the samples from the United States and Slovenia.

Elemental Composition of Different Slovenian Honeys Using k0- Instrumental Neutron Activation Analysis

The botanical origin of seven types of Slovenian honey was investigated by analysis of their elemental content using k0-instrumental neutron activation analysis. A total of 28 representative samples were collected from beekeepers all over Slovenia in 2 consecutive years. Nineteen of the 37 elements measured were present in amounts above their LOD. The present study suggests that the determination of only alkali elements might be sufficient for the classification of Slovenian honeys according to their botanical origin. Linden and multifloral honeys can be differentiated on the basis of Na content. The differentiation of forest, spruce, and fir honeys is possible on the basis of differences in Cs, K, and Rb content. The difference between Na and Rb content can be used as a discriminating tool between light and dark honeys, because light honeys (black locust, linden, and multifloral) contained more Na than Rb, whereas it was the opposite for dark honeys (chestnut, forest, spruce, and fir). Statistically significant correlations were found between K and Rb and between K and Cs content. This study represents a considerable step in filling the knowledge gap concerning both the determination of elements present in low concentrations and the botanical origin of Slovenian honey.

Development of methodologies for the analysis of uranium ores by k 0-instrumental neutron activation analysis and inductively coupled plasma atomic emission spectrometry

Analytical methodologies were developed for the determination of elemental contents in four uranium ore samples (S-8, S-12, S-13 and S-17) from IAEA by inductively coupled plasma optical emission spectrometry (ICP-OES) and semi-absolute k0-instrumental neutron activation analysis (k0-INAA) techniques. Combining the results for both techniques it was possible to determine 46 elements in the four ores. ICP-OES measured major elements, while k0-INAA quantified trace elements including rare earth elements. Application of principal component analysis successfully distinguished the samples on the basis of their lithologies.

Fruit of Morus nigra and Morus alba as environmental biomonitor: an elemental analysis by k 0-instrumental neutron activation analysis

In this study, potential of fruit of Morus nigra and Morus alba was evaluated as short-term biomonitor. Each variety of the fruits was collected from 13 different locations of Islamabad with different level of pollution. Both fruits were quantified by k0-instrumental neutron activation analysis. Pollution level was assessed by the application of enrichment factor (EF) and principal component analysis (PCA). EF revealed a source of (As, Hg, I and Se) and PCA showed the areas of high dust level. The overall analysis suggested that both fruits could be used as short-term biomonitor.

Spatial distribution of neutron flux in geological larger sample analysis at CDTN/CNEN, Brazil

Iron monitor wire was used to evaluate the neutron flux gradients inside 5 g-geological sample during irradiation. The spatial distribution for thermal flux was about 2 %/cm for radial and axial gradients and about 5 %/cm for radial and 2.5 %/cm for axial gradients for fast neutrons. The results were evaluated using reference material IAEA-SOIL-7 analysed as small and larger samples and tested with calculating E n numbers. This test pointed out that all results were consistent within a 95 % confidence interval. The contribution of the neutron flux gradients may be reduced for larger sample using the standard procedure of the k 0-instrumental neutron activation analysis.

Levels and Spatial Distribution of Airborne Chemical Elements in a Heavy Industrial Area Located in the North of Spain

The adverse health effects of airborne particles have been subjected to intense investigation in recent years; however, more studies on the chemical characterization of particles from pollution emissions are needed to (1) identify emission sources, (2) better understand the relative toxicity of particles, and (3) pinpoint more targeted emission control strategies and regulations. The main objective of this study was to assess the levels and spatial distribution of airborne chemical elements in a heavy industrial area located in the north of Spain. Instrumental and biomonitoring techniques were integrated and analytical methods for k0 instrumental neutron activation analysis and particle-induced x-ray emission were used to determine element content in aerosol filters and lichens. Results indicated that in general local industry contributed to the emissions of As, Sb, Cu, V, and Ni, which are associated with combustion processes. In addition, the steelwork emitted significant quantities of Fe and Mn and the cement factory was associated with Ca emissions. The spatial distribution of Zn and Al also indicated an important contribution of two industries located outside the studied area.

Multi-elemental characterization of indoor aerosols in elderly care centers

In general, elders spend more than 90 % of their daily time in indoor environments, leading to long exposure periods to indoor air pollutants. Although the recognized importance of the elders’ exposure to air pollution, the research studies have been paid attention essentially to other susceptible groups of people such as children. In order to fulfill this gap in the knowledge, the objective of this work was to perform a chemical characterization of air suspended particles collected in four elderly care centers (ECCs) by using k 0 instrumental neutron activation analysis (k 0-INAA). For that, particulate matter with aerodynamic diameter lower than 10 μm (PM10) was sampled in ECCs’ bedrooms, living-rooms and, at the same time, in the respective outdoors. The collected filters were irradiated at the Portuguese Research Reactor (nominal power: 1 MW) and measured using a coaxial germanium detector for the application of the k 0-INAA. Results showed that the PM10 indoor concentrations did not exceed the national and the international limit values and that PM10 concentration in living-rooms were significantly higher than in bedrooms. Zn and Cr presented higher concentrations in the indoor environments indicating the existence of indoor sources for these elements. The most enriched elements in relation to a reference soil were Sb, Zn, As and Cr indicating their association with anthropogenic sources. This article represents an innovation in the field of environmental chemistry since the PM chemical components have never been characterized in ECCs.

Determination of elements in different parts of goat brain using k 0 instrumental neutron activation analysis

Researcher’s interest is increasing worldwide to study the role of trace elements in brain tissues. This paper discusses the application of k0-instrumental neutron activation analysis to study the distribution of trace elements in seven different anatomical regions of goat brain. These regions include cerebellum, cerebrum, medulla oblongata, meninges, midbrain, pons and thalamus. The analysis protocol followed 1 h irradiation at 10 MW material testing type nuclear research reactor with nominal thermal neutron flux of 2 × 1013 cm−2 s−1. A total of 14 elements, namely Br, Co, Cr, Eu, Fe, Hg, K, Na, Rb, Sb, Sc, Se, Tb and Zn were determined in all parts. Reliability of the method was assessed by analyzing biological reference material IAEA-336 (lichen). On comparing the analytical results with the healthy human brain data, it showed that eight elements (Eu, K, Na, Rb, Sb, Sc, Se, Tb) were found with relatively higher elemental concentrations in human brain. Principal component analysis revealed distribution of seven parts in different three groups having similar elemental concentrations of elements.

Chemical profile of fugitive particulate emissions

Fugitive emissions pose problems both for general air quality management as well as for the operational management of the facilities. In harbours, activities such loading, unloading and transport of dusty materials are important sources of particulate fugitive emissions. Therefore, there is a growing concern about air quality in these areas as a result of the high impact of the operations on human health and environment. The objectives of this study were to estimate the impact of harbour activities on air particulate matter (APM) levels and to compile an inventory of chemical profiles of harbour particulate fugitive emissions. This preliminary work was based on experimental campaigns carried out in a Portuguese harbour when different types of bulk materials were handled. High time resolution monitors were installed close to the unloaded area and recorded APM concentrations and meteorological variables. PM2.5 and PM2.5–10 were collected during unloading operations and a complete chemical characterization of collected samples was made by the techniques k 0-instrumental neutron activation analysis and particle induced X-ray emission. Results showed that manipulation of materials during harbour operations resulted in high emissions of particles, especially from the coarse fraction. These emissions were very affected by the granulometry and chemical composition of the handled materials and by the meteorological conditions.

Assessment of the main natural radionuclides, minor and trace elements in soils and sediments of the Shu valley (near the border of Kazakhstan and Kyrgyzstan)

New data on the concentrations of the main gamma-emitting radionuclides, minor and trace elements, and isotopes of uranium (with Ra-226 as a daughter product of U-238) and thorium in soils and sediments of the Shu valley (from the river Chon-Kemin to the river Kuragatty downstream the river Shu) are presented, determined by high-resolution gamma-spectrometry, k0-instrumental neutron activation analysis and alpha-spectrometry with appropriate radiochemical separations of the samples, respectively. The results obtained showed an aquatic migration pathway of most of the trace elements and radionuclides and predicted water pollution downstream the river Shu. The scandium method showed pollution by As, Br, Ca, Cr, Zr of the Tasotkel dam impoundment and by Ca and Cr of the river Shu below its confluence with the river Kuragatty. According to the disequilibrium isotopic method for uranium (using the isotopic ratio U-234/U-238), areas with accumulation and leaching processes were estimated for soils and sediments of the river Shu and its main inflows.

Determination of aluminium, silicon and magnesium in geological matrices by delayed neutron activation analysis based on k0 instrumental neutron activation analysis

In this work, concentrations of silicon, aluminium and magnesium in geological matrices were determined by Neutron Activation Analysis based on k0-IAEA software. The optimum activation and delay times were found to be 5min and 15–20min respectively for the determination of Si via 29Si (n,p) 29Al reaction. The adopted irradiation scheme did not work for the determination of magnesium. Each sample was irradiated under a thermal neutron flux density of 5.0×1011ncm−2s−1. Cadmium covered activation indicated that a permanent epithermal irradiation site for research reactors would be very useful for routine determination of silicon in environmental samples.

K0-INAA of Venezuelan ceramics and complete statistical analysis to establish their provenance

A group of 46 archaeological figurines samples (ad 1300 and 1500) from Venezuelan mainland and northern island were analyzed by k0-instrumental neutron activation analysis (k0-INAA) to obtain their elemental content and give a step ahead to establish the provenance of the island figurines. In total 37 elemental concentrations were measured with uncertainties between 3 and 20 %. To make the study of provenance, a complete statistical analysis was achieved; Fisher linear discriminant, principal component analysis, hierarchical clustering and the Hotelling T2 test were used to this end. Furthermore, not only the 46 samples analyzed in this work by k0-INAA were used, but also 40 samples analyzed by PGNAA and reported by Sajo-Bohus et al. (JRNC 265(2):247–256, 2005) were included in the statistical analysis. It was done in order to increase the size of the data set, and then to obtain from the statistical techniques more reliable results. It was found that a very good differentiation exits between the figurines from the island and from the mainland supporting the idea that the raw materials of the figurines come from different places.

Performance evaluation of k 0-instrumental neutron activation analysis and flame atomic absorption spectrophotometry in the characterization of various types of alloys

Certified alloys of Ni–Cu based, Fe based and Cu–Sn based were analysed by semi-absolute, standardless k0-instrumental neutron activation analysis (k0-INAA) and flame atomic absorption spectrophotometry (FAAS) aiming at evaluating their comparative performances. In k0-INAA measurements, the irradiations were performed at miniaturized neutron source reactor having thermal neutron flux of about 1 × 1012 cm−2 s−1. The experimentally optimized parameters for INAA suggested a maximum of three irradiations for the quantification of 21 elements within 5 days. The same experiments also produced quantitative results of 13 elements not reported in the certificates of the reference materials. AAS was, however, unable to determine any of those elements. Accuracy of the two techniques was assessed by comparing their average root mean squared errors. The data analysis concluded that k0-INAA had better sensitivity and accuracy than FAAS.

Elemental characterisation of strawberry grown in Islamabad by k 0-instrumental neutron activation analysis and atomic absorption spectrophotometry and its dietary assessment

Mineral contents of strawberry, collected from different farms of Islamabad were analysed by semi-absolute k0-instrumental neutron activation analysis and atomic absorption spectrophotometry. The samples were irradiated at two research reactors located in Pakistan Institute of Nuclear Science & Technology (PINSTECH), Islamabad. The analytical methodologies were validated by analysing reference materials, IAEA-336 (lichen) and IAEA-V-10 (hay powder). In all the samples, a total of 26 elements were quantified, among them 16 elements (Ca, Cd, Cl, Co, Cr, Cs, Fe, K, Mg, Mn, Na, Pb, Ru, Sc, Sr and Zn) were found in all the samples. The determined elemental concentrations in strawberry were compared with the reported values from other countries. In comparison with the mineral contents of other fruits, strawberry stands best source of Mn and the second most important source of K after banana. Intake of trace metals through this source was calculated and it was found that strawberry provides Mn (1.95–3.68 mg/kg), Cr (19.2–46.3 × 10−3 mg/kg), Fe (3.45–8.72 mg/kg), K (1,520–1,670 mg/kg) and Mg (100–220 mg/kg), which forms 26, 19, 14, 7 and 7% of the recommended dietary allowances for the respective metals. The daily intake of Cd and Pb were compared with the provisional tolerable weekly intake defined by FAO/WHO.