Single-crystal trace element analysis in rock-forming minerals by instrumental neutron activation analysis

We have developed an INAA techniques for analyzing single crystals extracted from rocks. Trace element contents have been measured in a large variety of mineral species, as well as isotopic ratios of some REE in minerals related to natural fission reactions. The sensitivity of INAA allows to avoid the main shortcomings of usual mineral geochemistry: (1) only very short quantities of minerals are needed (down to a few g), so that even very sparse minerals could be analyzed, (2) purity of minerals is carefully checked, and (3) the heterogeneity of a population may be studied. The method is especially useful when applied to minerals acting as tracers for some element families, e.g. REE in Ca-bearing minerals (fluorite, apatite, titanite, gamet) and Zr-bearing minerals, or chalcophile elements (Co, Ni, As, Sb, Mo, Ag, Au and Se) in sulfides. We present an application of the method to the Oklo U deposit in Gabon showing that features outlined above are of special interest for the study of hydrothermal processes.     

Determination of trace element levels in polyethylene by instrumental neutron activation analysis

Elements Al, As, Au, Br, Cl, Co, Cr, Cu, Fe, Hg, K, La, Mn, Mo, Na, Sb, Sc, Sm, V, and Zn were determined by INAA in several brands and batches of high pressure polyethylene (PE) Bralen (Slovnaft Bratislava, Czechoslovakia). A large scatter of trace element contents was found in both granules and foils, indicating an inhomogeneous distribution for the majority of the above mentioned elements present as impurities in PE. Larger amounts of the elements Al, Mn, and Sb were found in foils than in granules. Blank values resulting from using of PE Bralen as a canning material for INAA were compared to trace element concentration in human hair samples, too.     

Determination of trace element concentrations of indian cigarette tobacco by instrumental neutron activation analysis

Lung cancer and smoking are associated. Epidemiological studies show that not only lung cancer but other chest diseases have causative relationship with smoking. Cigarette tobacco and smoke contains many carcinogens. Inorganic and metallic constituents of cigarette tobacco and smoke have not been studied as extensively as the organic compounds. Since some of the metals are highly toxic and also carcinogenic, authors have attempted to measure the levels of some of the trace elements of Indian tobacco by instrumental neutron activation analysis, and compared the results with the tobacco of America, Germany, Iran and New Zealand.     

Variations in trace element concentrations in human blood serum in the normal state investigated by instrumental neutron activation analysis

Using instrumental neutron activation analysis, the variations in the serum levels of Br, Cs, Na, Rb, Se, and Zn were investigated in 18 persons in the normal state. By determining the element levels in relation to changes is the serum water content, information about the binding to the serum protein was obtained. The influence of physiological factors on the serum element levels was investigated. Changes in the concentrations due to variations in the protein/water ratio and in the zinc level as a result of different posture were observed. When standardized sampling procedures were used, the variations in the serum element concentrations during one hour and from day were found to be less than 10%.     

Determination of trace element pathways in a petroleum distillation unit by instrumental neutron activation analysis

The concentrations of 11 trace and minor elements (Na, Al, S, Cl, Ca, V, Mn, Ni, As, Br, I) have been measured by instrumental neutron activation analysis in a sample of crude oil from Venezuela, and in 7 of its distillates and in the final residue produced in a primary distillation unit. Concentrations range from 0.5 ppb to 2.0%. The elements have been classified in 4 categories on the basis of their distributions among the fractions analyzed. The results on concentrations have also been used to establish elemental balances in the distillation unit studied operating under steady-state conditions. Only S and V have been found to give rise to losses by emission.     

Feasibility of instrumental neutron activation analysis for trace element studies in natural soils

Fifty natural surface soils with strongly variable organic matter content and elemental composition were investigated to see to what extent INAA would prove useful for multi-element surveys. A conventional scheme of irradiations and decay intervals was used and 35 elements were investigated. Detection limits of the various trace elements were studied with respect to the influence of elements giving rise to major radionuclides in activated samples. For the 18 elements Na, Al, K, Sc, Cr, Mn, Fe, Co, Zn, Br, Sb, Cs, Ba, La, Sm, Hf, Th, the performance of INAA was very good. Useful results were also obtained for V, As, Se, Rb, Sr, I, Ta, and Au, while the technique appeared marginal for Cl, Zr, Mo, Ag, and Hg, and unsatisfactory for Mg, Ti, Ni, and Cd.     

Trace element concentration in human gallstones using instrumental neutron activation analysis

The concentrations of trace elements in two types of gallstones in 24 female patients in Tripoli aged 24–60 years have been determined using instrumental neutron activation analysis. These elements are Co, Fe, Mn, Se and Zn. The results are expressed in ppm and are in agreement with reported values. The data suggested that the concentrations of trace elements increase with age.Presented at the MTAA-8 Conference, September 16–20, 1991, Vienna, Austria.     

Trace element concentrations in human bone using instrumental neutron activation analysis

Instrumental neutron activation analysis has been applied to analyze 23 bone samples obtained from Libyan patient aged (3–80) years for the study of the concentration levels of trace elements Ba, Br, Ca, Fe, Sr and Zn and their concentration pattems regarding to the age and sex of the patients.     

Determination of trace elements in fish by instrumental neutron activation analysis

Instrumental neutron activation analysis, INAA, was utilized for the determination of Al, Au, Br, Ca, Cl, Co, Cr, Cu, Fe, I, K, Mg, Mn, Na, Rb, Sc, V and W in 12 Tilapia Nilotica samples collected from the Aswan High Dam Lake following the destructive techniques.     

Determination of trace elements in carbonates by instrumental neutron activation analysis

A systematic non-destructive determination of eighteen trace elements (F, Na, Cl, Sc, Mn, Zn, Br, Sr, I, Ba, La, Ce, Sm, Eu, Tb, Yb, Th and U) in carbonate samples by thermal neutron activation analysis was developed. Three 0.2–0.5g samples were irradiated for 15 sec (in the case of determination of F), for 3 min (in the case of Na, Cl, Mn, Sr and I) and for 60 hrs (in the case of Sc, Zn, Br, Ba, La, Ce, Sm, Eu, Tb, Yb, Th and U) in the TRIGA MARK II Reactor at a thermal neutron flux of 5·10¹¹ n·cm⁻²·sec⁻¹ (15 sec and 3 min irradiation) and 1.5·10¹²n·cm⁻²·sec⁻¹ (60 hrs irradiation), respectively. According to the half life of the nuclides formed, the activities were measured with a Ge(Li) spectrometer as follows,²⁰F∶15 sec counting after 20–25 sec cooling,²⁴Na,³⁸Cl,⁵⁶Mn,^87mSr and¹²⁸I∶600 sec couting after 30–120 min cooling,⁸²Br,¹⁴⁰La,¹⁵³Sm,¹⁷⁵Yb and²³⁹Np (daughter of²³⁹U)∶3000 sec counting after 1 week cooling,⁴⁶Sc,⁶⁵Zn,¹³¹Ba,¹⁴¹Ce,¹⁵²Eu,¹⁶⁰Tb and²³³Pa (daughter of²³³Th)∶5000 sec counting after 1 month cooling. The errors due to the fluctuation of the neutron flux and the counting geometry were minimized by the use of calcium determined previously with EDTA-titration as an internal standard. The interferences from²⁴Mg(n, p)²⁴Na and²³⁵U(n, fission) reactions were corrected by the activities produced by the reactions in unit weight of magnesium and uranium, and their concentrations in samples measured experimentally. The data of Na, Mn, Zn and Sr were compared with the results obtained by atomic absorption analysis.     

Determination of trace element concentrations of Libyan chewing and cigarette tobacco by instrumental neutron activation analysis

The concentration of 12 trace elements in the chewing tobacco and two different brands of Libyan cigarette Atlas and Sport has been measured by instrumental neutron activation analysis and compared to the results of cigarette tobacco from India, USA, Iran and Yugoslavia. These elements are Co, Cr, Cu, Fe, Hf, Mn, Rb, Sc, Th, U, V and Zn.     

Preliminary study of trace elements in human brain tumor tissues by instrumental neutron activation analysis

Elemental profiles of brain tumor tissues from 15 patients of astrocytomas (grade I–III) and normal human brain tissues of 23 male age matched autopsies as controls have been studied by instrumental neutron activation analysis. The SLOWPOKE reactor with a thermal neutron flux of 8·10¹¹n·cm^–2·s^–1 and swimming pool type reactor with a thermal neutron flux of 1·10¹³n·cm^–2·s^–1 were used for short and long irradiation of samples, respectively. Spectrophotometry was only used for analyzing phosphorus. A total of 18 elements Se, Na, K, Br, Cl, Mn, Mg, S, Ca, Cu, Hg, Cr, Fe, Rb, Zn, Co, Sc and P has been determined for this purpose. The reliability of methods has been checked by analyzing biological standard reference materials horse kidney (IAEA H-8) and bovine liver (NBS SRM 1577a). The analytical results showed that compared with the normal brain tissues, concentrations of Ca, Fe, Cu, Zn, Se, Mn, Br and Sc were significantly higher in tumor tissues (P<0.01) and concentrations of Rb, K and P were lower, while no differences for contents of Mg, S, Cr, Hg, Na and Cl were observed. A negative correlation between P and Ca in malignant and normal brain tissues was observed.     

Characterization of trace elements in medicinal herbs by instrumental neutron activation analysis

Medicinal herbs are often used as alternative medicines for healing and controlling some diseases in the world. This study focuses on the content of heavy and trace elements of some widely consumed herbs in Libya. Nine most popular herbs were analyzed by k ₀-instrumental neutron activation analysis. All the samples, SRM and flux monitors were irradiated for 7 and 10 hours under thermal neutron flux of 1.3·10¹³ cm⁻²·s⁻¹ at Tajoura nuclear reactor. In total, 33 elements were analyzed in different herbs. The variations in the concentration of the elements are attributed to soil composition and the climate in which the plant grows. The study showed that the toxic elements found in the samples were below the levels prescribed by health regulations. The precision and the accuracy of the results were evaluated by analyzing the reference materials Pine Needles SRM 1575 and Citrus Leaves SRM1572.     

Determination of trace elements in Nigerian kola-nuts by instrumental neutron activation analysis

The trace elements content of Cola acuminata and three varieties of Cola nitida have been determined using neutron activation analysis. The samples have been irradiated at the Joint Universities Research Reactor, Risley, England for 7^1/2 hours in a neutron flux of 2.5·10¹² n·cm^–2s^–1 and analysed using high resolution lithium drifted germanium detector coupled to a Canberra 35 microprocessor as a 4096 channel gamma spectrometer. The elements: Na, K, Br, W, Fe, Cs, Co, Zn, and Sc were detected.     

Determination of trace elements in Egyptian molasses by instrumental neutron activation analysis

Multielement neutron activation analysis has been applied to the determination of macro, micro and trace amounts of Al, Br, Ca, Cl, Co, Cr, Cs, Fe, K, La, Mg, Mn, Na, Rb, Sc and V in molasses of Kom Ombo, Edfu, Armant, Naga Hammady and Abu Korkass cane sugar factories. The threshold element concentrations are acceptable and below the safety. Differences in element concentrations may be related to different botanic textures and structures, different compositions of sugar cane plants, corrosion of containers or changes in soil as a result of geochemical differentiation. The method is sensitive down to 0.038 ppm of V. The relative errors due to counting statistics are in the range of 0.2–11%.     

Determination of rare earth and other trace element abundances in human kidney stones and brain tissue by instrumental neutron activation analysis

We have used INAA to analyze more than 30 minor and trace elements in 10 human kidney stones (phosphate and oxalate types). In addition we also analyzed human brain tissue samples for trace elements by INAA to determine the limitations of the method. Samples were taken from the temporal and frontal cortex of the brain of a patient that suffered from dialysis encephalopathy (where an increased Al content is expected), as well as a number of control samples. Trace elements were analyzed to study possible compositional differences other than the Al content. The analyses were done using large volume HPGe detectors; because of the low abundances, accuracy and precision vary between 3–80% for individual elements. We found a difference between the rare earth element (REE) patterns for apatite and oxalate kidney stones, and a fractionation compared to typical REE contents in plants. For the brain samples there is evidence for differences between the dialysis patient and the control samples not only for Al, but also for some other elements including the REEs, but most differences are minimal, and may not be significant.     

Trace element exposure in man by instrumental neutron activation analysis of hair

A nondestructive instrumental neutron activation technique was used to analyze human hair samples collected from people living in metropolitan and rural areas in Korea. Samples were also collected from factory workers and cancer patients. Hair from metropolitan area residents contain higher concentrations of Ca, Mg, Zn, Cu, Na, Br, Mn, I and S than rural area residents. Concentrations of I and S from cancer patients, Mg, Zn, Al, Na, Mn and As from glassware workers were relatively higher. The results show that the trace element concentrations of the hair are possibly related to the trace element concentrations in the body.     

Determination of trace elements in carbonate reference samples by instrumental neutron activation analysis

Twenty elements (Sm, U, As, Sb, La, Ce, Yb, Th, Cr, Eu, Hf, Ba, Cs, Tb, Sc, Rb, Fe, Zn, Ta, Co) have been determined by instrumental neutron activation analysis in GSJ/AIST carbonate reference samples, JCp-1 (Coral) and JCt-1 (Giant Clam), together with JLk-1 (Lake Sediment), JDo-1 (Dolomite) and JLs-1 (Limestone) reference samples.     

Determination of trace elements in sugar cane refuse by instrumental neutron activation analysis

Multielemental instrumental neutron activation analysis has been utilized for the determination of micro, trace and ultratrace amounts of Al, As, Au, Br, Ca, Cl, Co, Cr, F, Fe, K, La, Lu, Mg, Mn, Na, Sc, V and W in sugar cane refuses of Armant, Kom Ombo, Edfu, Deshna and Naga Hammady Factories. The element concentrations are below the safety baseline levels. Variations of results may be related to different botanic structures, different compositions of sugar cane plants or ecologic changes in soil. The method is accurate and precise. The relative errors are in the range of 0.3–12.3%.     

Determination of trace elements in Chinese medicinal plants by instrumental neutron activation analysis

Roots of Astragalus membranaceus, Angelica sinensis, Glycyrrhiza uralensis and Codonopsis pilosula, which were often used as herbs in traditional Chinese medicine, were analyzed by Instrumental Neutron Activation Analysis (INAA). The samples were collected in Gansu, northwest of China and irradiated at the 15 MW heavy water reactor in China Institute of Atomic Energy (CIAE). The induced activities were counted by a well calibrated low background γ-spectrometer equipped with a high efficiency coaxial high-purity germanium (HPGe) detector. The concentrations of eighteen trace elements (Ca, Fe, Na, Zn, Ba, Rb, Ce, Cr, La, Co, Th, Cs, Sb, Sc, Sm, Hf, Eu and Tb) in the herbs were determined. Possible links between pharmacological action of the herbs and content of some elements were also discussed in this paper. The measured results were compared with the reported values in literature.