Use of combined NAA and SIMS analyses for impurity level isotope detection

Instrumental neutron activation analysis (INAA) and electro-thermal atomic absorption spectrometry (ETAAS) were employed to determine the toxic elements in fourteen fruits harvested in Pakistan. As, Br, Hg, Sb and Se were determined using INAA. Cadmium and Pb were determined using ETAAS. The intake levels of all toxic elements have been calculated. The data show that dates supply the maximum amount of most of the toxic elements. Peels of apple and pear have also been investigated and were found to contain higher concentration of toxic elements than their edible parts. The reliability of the techniques has been established by the use of standard reference materials. This study shows that all investigated fruits cultivated and consumed in Pakistan are safe for human consumption.     

Dietary evaluation of toxic elements through integrated diet

Several potentially toxic trace elements, namely, Hg, Pb, Cd, As, Sb, Br and Se have been measured by INAA in combination with AAS techniques in the integrated diet representative of the inhabitants of Gujranwala, a highly industrialized city of Pakistan. The dietary intake values for these elements have been estimated from the prevailing concentration level in the summer and winter season diets, which reveals that present intake data are well within the reported WHO values and can be considered to be safe. Posslble sources of food contamination by the toxic elements and their adverse impacts on human heaith are briefly discussed.     

INAA and AAS of different products from sugar cane industry in Pakistan: Toxic trace elements for nutritional safety

Instrumental neutron activation analysis (INAA) have been used to determine As, Br, Hg, Sb and Se in combination with atomic absorption spectrometry (AAS) as a complementary technique for the quantification of Cd and Pb in jaggery, brown sugar, white sugar and molasses. All sugar cane products were collected from the local sugar cane industry of Pakistan. The highest concentration of these potentially toxic elements was quantified in molasses; however, molasses together with jaggery, brown sugar and white sugar contains trace amounts of all of these elements. Due to very low concentration of Cd it could only be detected in molasses. To evaluate the percentage contribution of these elements in the sugar cane products to the weekly recommended values, intakes on weekly consumption of 100 g of each item have also been calculated which follow the pattern Br>Se>Pb>Hg>As>Sb. The elevated Br contents may be attributed to the use of Br-containing chemicals for fumigation; however, these contents are well within the tolerance levels. The estimated weekly intake of all toxic elements is very low indicating that sugar cane products can be safely ingested as part of the diets.     

Determination of trace elements in coffee beans and instant coffee of various origins by INAA

Summary Extensive use of coffee, by one-third of world's population, entails the evaluation of trace element contents in it. Instrumental neutron activation analysis (INAA) was successfully employed to determine the concentration of 20 trace elements (essential, toxic and nonessential) in four samples of coffee beans of various origins and two instant coffee brands most commonly consumed in Pakistan. This study provides the base-line values of certain toxic and essential elements in coffee. The daily intake of essential and toxic elements through coffee was estimated and compared with the recommended values. The cumulative intake of Mn is four times higher than the recommended value and that of toxic elements is well below the tolerance limits.     

Determination of protein-bound trace elements in bovine kidneys

Concentrations of up to 16 elements have been determined in subcellular fractions of bovine kidney using INAA methods. Levels of Rb and Se have been measured by a cyclic INAA method. A conventional INAA method consisting of 2 irradiations and 3 counting periods has been employed to determine the other elements. Accuracy of measurements has been evaluated by analyzing several standard reference materials. Trace element content of reagents used has been investigated in detail. Fresh samples of bovine kidney have been homogenized in a buffer containing sucrose and HEPES, and the homogeneate separated into nuclei, mitochondrial, lysosomal, microsomal and cytosol fractions by successive differential centrifugation. Concentrations of trace elements have been measured in these fractions using the INAA methods.     

Determination of trace and toxic elements in Korean rice CRM by INAA, ICP and AAS

Trace and toxic elements in Certified Reference Material (CRM) made of Korean rice at the Korea Research Institute of Standards and Science have been analyzed by Instrumental Neutron Activation Analysis (INAA). Data intercomparison from the measurement with those of Atomic Absorption Spectrometry (AAS) and Induced Coupled Plasma Spectrometry (ICPS) has been studied. The powdered samples were sterilized at 1.5·10⁶ rad in the bottles using a⁶⁰Co source after sieving and spiking to specific elements such as As, Cd, Cr, Cu and Hg and then the homogeneity of samples was assessed. Rice flour (SRM 1568a) and standard solutions made by the National Institute of Standards Technology (NIST) were used to construct the calibration curves for the INAA and the chemical methods, respectively. The uncertainties and concentration of constituent elements were determined and the possibility of their use for analytical quality control was considered.     

Measurement of rare earths elements in Kakul phosphorite deposits of Pakistan using instrumental neutron activation analysis

The rare earth elements (REEs) content of Kakul phosphate rock (PR) from different localities of the main Hazara deposits of Pakistan were determined using instrumental neutron activation analysis (INAA). 25 phosphorite samples were collected from different phosphorite sites and 6 samples representing different batches from the crushing plant near Kakul Mine. Concentrations of seven REEs (Ce, Eu, La, Lu, Sm, Tb and Yb) were determined in the PR samples. The highest amounts of Heavy and light rare earth elements (HREE and LREE) were quantified in the PR samples collected at the Phosphate Rock Crushing Plant while the lowest amounts of these REEs were measured in the Lambidogi Phosphorite deposit samples. Comparison with global data showed the REEs content of the studied PRs show lower range for all REEs and mostly comparable to the data reported by Israel and Syria. Calculated chondrite ratio for these elements depicts enrichment of LREEs in all phosphorite deposits.     

Instrumental neutron activation analysis based on k0-standardization method as compared with other methods in the analysis of the IAEA inter-comparison test

Results of inter-comparison test organized by the IAEA are analyzed according to the contribution and performance of INAA as non-destructive method for trace elements analysis as compared to other techniques. Several methods were employed for certifying the biological sample (IAEA-0140) and were also compared. It is shown that NAA is the method of a good accuracy and precision. The biological sample has been investigated by INAA based on semi-absolute technique. More than 30 elements have determined without using standards. The reference materials, which are certified in this manner and utilized as primary standard, are also discussed. This revised version was published online in August 2006 with corrections to the Cover Date.     

INAA and flame AAS of various vegetable reference materials

Summary INAA and flame AAS have been used for the analysis of a large number of vegetable reference materials. Out of all determined elements (28 by INAA and 11 by AAS) nine are common for both methods (Ca, Cd, Co, Cu, Fe, Mg, Mn, Na, Zn) and for these the possibilities of the two methods have been compared.     

Mineral profile of Ghanaian dried tobacco leaves and local snuff: A comparative study

The concentration of thirty-four elements each in Ghanaian dried tobacco leaves and snuff (powdered tobacco) have been determined using instrumental neutron activation analysis (INAA). The concentration of Hg, Cr, As and Cd in both set of samples were found to be in excess of WHO limits for drinking water, thus indicating potential toxicity of the samples. Cr, Cd, Sb and Cu were two to eight times high, whilst As and Hg were comparable in powdered tobacco and tobacco leaves. The aim of the study was to determine the pattern of elemental concentrations and the toxicological strengths in both tobacco leaves and tobacco powder. The results indicated that the toxicity of the snuff was higher than the tobacco. This indicated strongly that from the medical point of view, the level of toxic accumulation in users might be potentially high in the tobacco powder compared to the leaves. Thus, education of the Ghanaian public on the threshold value of toxic elements contained in both set of samples was suggested to safeguard users against these addictives.     

Analysis of marine samples by neutron-induced prompt gamma-ray technique and ICP-MS

Multi-element and isotopic analyses of oils and marine environmental samples were carried out to estimate a contamination source using a "finger printing" method. Elemental analyses were carried out using neutron-induced prompt gamma-ray analysis (PGA), instrumental neutron activation analysis (INAA) at the Japan Atomic Energy Research Institute, Tokai-mura, Japan (JAERI) and ICP-MS in the IAEA Marine Environment Laboratory, Monaco (MEL). Fifteen elements including light elements, H, B, N, Si and Ca, which cannot be determined by INAA and ICP-MS, were determined by PGA. A total of 47 elements were determined in the present study. The potential of PGA for the determination of isotopic ratios was tested by measuring ³⁴S/³²S ratios in oils. The evaluation of historical records of marine environmental conditions using annual bands in coral samples was also investigated.     

Nuclear methods of analysis applied to quantitation in laser microprobe mass spectrometry

Laser microprobe mass spectrometry (LMMS) detection limits for mercury have been determined using mercury-doped Spurr's tissue embedding medium. Actual mercury concentrations were confirmed via INAA. Procedures have also been developed to measure lithium and indium concentrations in thin films of polymerized Spurr's samples via PIGE and PIXE. These elements are currently being investigated as laser power density internal standards in the analysis of human tissue for studies of trace element involvement in neurological diseases.     

A study on some trace elements in Chilean seafood

Levels of essential and toxic trace elements in six marine species greatly in demand in the international market (canned pink clams, razor clams, clams, king crab, sardines, and frozen albacore tuna fish) were studied. A special laboratory adequately equipped for handling and preparing biological materials, is described. The elements As, Br, Na, Se, Hg, Cr, Fe, Zn and Rb were determined by INAA, while copper and cadmium content were determined using RNAA. Significant differences were found on comparing the contents of some toxic elements in mollusk and other samples of marine food. Various certified reference materials (CRMs) of the IAEA, NIST and NIES were analyzed for quality assurance purposes.     

Nutritional and Environmental Properties of Algal Products Used in Healthy Diet by INAA and ICP-AES

Spirulina platensis alga sampled in the Caribbean Sea and seven other commercial algal products available on the Italian market of different origin and aspect, have been analyzed by instrumental neutron activation analysis (INAA) and inductively coupled plasma-atomic emission spectrometry (ICP-AES). By neutron irradiation and -ray spectrometry (INAA), as many as 20 elements could be measured instrumentally without any chemical treatment. Cu, Mg, Mn and Pb were determined after dissolution of the sample by ICP-AES. The cross-checking of the data, specifically by comparing those of Ca, Cr, Fe and Zn, obtained by the two techniques was found to be in good agreement. Special attention from analytical and nutritional point of view has been devoted to the toxic metals. The measurements have been carried out employing the reference algal material prepared by International Atomic Energy Agency (IAEA).     

Activation analysis study on subcellular distribution of trace elements in human brain tumor

The concentrations of up to 11 elements in subcellular fractions of human brain (normal and malignant tumor) have been determined by a combination of gradient centrifugation and INAA methods. Samples of human brain were homogenized in a glass homogenizer tube, the homogenate was separated into nuclei, mitochondrial, myelin, synaptosome fractions, and these fractions were then analyzed using the INAA method. The discussions of elemental subcellular distributions in human brain malignant tumor are presented in this paper.     

Excitation functions and energy spectra of proton induced reactions on56Fe and57Fe in the energy up to 30 MeV

The atmospheric particulate of industrialized cities had become a mixture of potentially toxic substances whose concentrations must be monitored to assess the pollution levels. Trace metals and elements are part of these pollutants and the knowledge of their total concentration in the air as well as their distribution in the different aerosol particle sizes is necessary to evaluate the pollution risk in terms of maximum present levels and long term exposure. In the present work, a preliminary part of a study initiated for monitoring the trace element levels present in the atmospheric particulate of the city of Milan (north Italy) and of its suburban areas is presented. More than 25 elements have been determined in Milan downtown along a period of three years and in different weather conditions. The granulometric distribution of selected potentially toxic elements (such as vanadium, lead, cadmium, nickel) has been also determined to evaluate their concentrations in different inhalable fractions (alveolar and bronchial — tracheal). Instrumental Neutron Activation Analysis (INAA) has been used for the determination of the great part of the elements while Graphite Furnace Atomic Absorption Spectroscopy (GF-AAS) has been employed for the determination of lead and, in some cases, for nickel, cadmium and copper.     

A contribution to the certification of some elements in eight vegetal reference materials by using instrumental neutron activation analysis

Instrumental neutron activation analysis (INAA) has been applied to the determination of 21 elements in 8 different vegetal samples, to be used as reference materials in 35 European laboratories (CII). Many of these elements hitherto have not been evaluated; they can be useful markers in many environmental problems. The INAA values are compared with CII non-nuclear analytical techniques results. Some rare earths elements (REE) have been also determined and their chondritic ratio versus atomic radius is reported.     

Studies of iron,cobalt and chromium distribution in some continental aquatic ecosystems and biological materials

The aim of the present work was to investigate iron, cobalt and chromium distribution in samples of living and non-living matter by using instrumental neutron activation analysis (INAA). Investigations were carried out starting with water systems components, such also specias living in these systems and biological tissues from rat and human organs. The following conclusions have been drawn for elements distribution in the relation enviromment/living matter: (1) iron, cobalt and chromium contents in plankton are very close to these found in suspended materials; (2) among all the investigated living organisms, the highest contents of investigated elements have been found in fish; (3) inspite of the contents of iron, cobalt and chromium being somewhat lower in bentos and crustacea than in suspended materials, all the obtained values are very close, and (4) human liver has somewhat higher iron- and cobalt-contents than rat liver, which, however, has higher chromium concentration. Of all the investigated living organisms chromium content was the lowest in human liver.     

Determination of trace elements in bottled water in Greece by instrumental and radiochemical neutron activation analyses

Summary Four different bottled water brands sold in Greece in the winter of 2001-2002 were analyzed for a wide range of chemical elements, using neutron activation analysis (NAA). The elements Na and Br were determined instrumentally (INAA), whereas the other metals and trace elements radiochemically (RNAA). The results indicated that the mean level of all the elements determined in the samples were well within the European Union (EU) directive on drinking water and accomplish the drinking water standards of the World Health Organisation (WHO) as well as of the Food and Drug Administration (FDA).