Alpha-activation analysis of boron on Si surface and in Si and SiO2 films

Brazil has become the largest producer of biomass ethanol derived from sugar cane. The industrial production is based on the fermentation of sugar cane juice by yeast, inside of large volume vats, in a fed-batch process that recycles yeast cells. To study the dynamics of chemical elements in each operating cycle, five stages of the fementation process were considered: must, yeast suspension, wine, non-yeast wine and yeast cream. For this, a mass balance of the terrigenous elements, Ce, Co, Cs, Eu, Fe, Hf, La, Na, Sc, Sm, and Th, and the sugar cane plant elements, Br, K, Rb, and Zn, were established in fementation vats of an industrial scale unit, with sampling undertaken during different climatic conditions (dry and rainy periods). A similar distribution of the sugar cane characteristics elements was found for the stages analysed, while for the terrigenous elements a trend of accumulation in the yeast cream was observed. Preferential absorption of Br, K, Rb, and Zn by yeast cells was indicated by the smaller concentrations observed in yeast suspension than in yeast cream.     

Neutron activation analysis of saliva: Application in clinical chemistry,environmental and occupational toxicology

The contents of 21 chemical elements (Ag, Br, Ca, Cl, Co, Cr, Cs, Fe, Hg, K, Mg, Mn, N, Na, P, Rb, Sb, Sc, Se, Sr, Zn) in mixed non-stimulated saliva of 52 relatively healthy people were assessed by activation using 14 MeV neutrons and nuclear reactor neutrons. The study included 45 women and 7 men, aged 18 to 35. The dependence of salivary composition upon sex, age, time-of-day and time-of-year was studied. The saliva of 22 men, involved in the clean up operation after the Chernobyl accident, was also studied. There existed clear circadian variations in the amount of Na, Sc and Cr contained in the saliva and a tendency to circadian variations for the amount of Cl, Co, Br and Rb. Neither sex, age, nor time-of-year influenced the contents of 21 chemical elements examined. The only exception to this finding was with Hg, whose content increases with age. The analysis of the cleaners' saliva made it possible to find considerable metabolic changes of Ca and some other chemical elements.     

Chemical changes in bromeliad leaves at different vegetative stages

Studies concerning the accumulating capacity of native epiphytic bromeliads are of utmost relevance, due to the continuous incorporation of chemical elements provided by these organisms in the ecosystems. Bromeliad species from diverse São Paulo State conservation units, Brazil, were sampled for young, mature and old leaves using a sustainable sampling method. By applying INAA, the accumulation of ten chemical elements, i.e. Br, Ca, Co, Fe, K, Na, Rb, Sc, Sr and Zn, was investigated in different leaf vegetative stages. The bromeliads showed divergent chemical element distribution patterns, demonstrating a real complexity in the accumulation and translocation mechanisms utilized by these plants.     

Multi elemental analysis of indigenous food spices in Southern Ethiopia using INAA technique

The objective of this study is a quantitative and qualitative analysis of essential and trace elements of four indigenous Ethiopian spices and herbs using instrumental neutron activation analysis technique. Results obtained for 16 elements: Major elements; Mg, Cl, and K; Minor elements; Na, Fe, and Mn, Zn, Br. While Al, V, Sm, Sc, La, Ba, Eu, Rb were found in traces. The spices, Affromumom korarima and Lippa Adonesis var. Koseret sebsebe were found to be very good sources of essential trace elements like Fe, Zn and Mn. The highest concentration of Mg was found in Ajowan whereas K and Fe were measured in Coriander seeds. The average daily dietary intake of some essential elements from the use of these spices were found to be below the recommended upper limit by WHO.

     

Study on chemical species of inorganic elements in some marine algae by neutron activation analysis combined with chemical and biochemical separation techniques

The compositional changes of inorganic elements on freshwater leaching of 35 species of Chinese algae were studied by the determination of the element contents in marine algae using instrumental neutron activation analysis. It was found that alkali metals and chlorine mainly exist as ions in algae, in which, water-soluble K and Na exist as chlorides. While, other elements exist as the states of both ions and organic combination in which the water leaching ratios of alkaline earth metals are the lowest. The combination of trace elements with various organic macromolecules inSargassum kjellmanianum was also studied using neutron activation analysis combined with chemical and biochemical separation techniques. The results indicate that the concentration of many trace elements, such as Zn, Fe, Sc, Th are earths in protein are quite high, and some trace elements can also be combined by pigment and polyphenol. Alkaline earth metal mainly bind with alginic acid inSargassum kjellmanianum.     

Determination of trace elements in tea leaves by neutron activation analysis

Instrumental neutron activation analysis has been employed to determine 14 trace elements in two brands of Iranian and foreign tea. The elements are: Br, La, Ba, K, Mn, Cl, Cr, Cs, Rb, Fe, Co, Zn, Sc and Au. The transference ratio of the elements into solution, when tea is leached by percolation, is also reported. It was found that some elements are totally transferred into solution and some are partially retained by the leaves.     

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     

Multielemental analysis of metallurgical samples by thermal neutron activation

Instrumental neutron activation analysis (INAA) was applied to investigated a total of 16 samples of raw materials, intermediate and final products involved in metallurgical processes in Romanian Iron and Stell works Sidex Galatzy: iron ores and pellets from different regions of the world, cast iron, slag and steels. A series of chemical elements was determined in the analyzed samples: Al, As, Ce, Co, Cr, Fe, La, Mn, Na, Sc, Sm, V, W. A qualitative discussion regarding the passing of from elements with different chemical affinity for oxygen compared to that of iron, from the raw materials to slag or to finite products is presented.     

Microviscosity of ions and salting-out in the extraction of rare-earth and transplutonium elements

A chemical procedure has been developed for the separation of U, Th, Fe, Sc, Na, Ta and Mo, which interfere in neutron activation analysis of the lanthanide elements in rocks. This methods in based on the extraction of interferents, before irradiation of the samples, using a solution of tetracycline in benzyl alcohol. The lanthanide elements remain in the aqueous phase and are coprecipitated with calcium oxlate or ferric hydroxide for irradiation and subsequent determination by gamma-ray spectrometry. Conditions for the separation of these interferences are examined determining the extraction curves. The chemical separation procedure was applied in the analysis of lanthanides in geological materials and the results showing the accuracy and the reproducibility of the method are presented. The sensitivity for all the lanthanides was determined.     

Distribution of trace and minor elements in hungarian spice paprika plants

Detailed investigations were carried out to study the distribution of trace and minor elements in different parts (fruit, seed and rib, peduncle, stem, leaf, root) of ripe Hungarian spice paprika plants. Two varieties of paprika plants were analyzed for their Cl, Co, Fe, K, Mg, Mn, Na, Rb, Sc, V and Zn content by non-destructive neutron activation analysis. The results showed that the iron contents of the samples were much higher than those of the other trace elements. For the trace elements Co, Fe, Mn, Sc, V and Zn a considerable enrichment was observed in the leaf, while the Rb and K, Na, Mg showed accumulation mainly in the peduncle. In the other parts (fruit, seed and rib, stem) of the paprika plants no significant enrichment of trace elements was found. Since some of the elements investigated may have been partially eluted during the cleaning of the roots with distilled water and, on the other hand, if the cleaning was not intensive enough, some soil particles could be retained on the samples, the data obtained for the roots should be considered with precaution.     

Instrumental neutron activation analysis of “melian”potsherds

Instrumental neutron activation analysis has been applied for the determination of 20 minor and trace elements (As, Ce, Co, Cr, Cs, Eu, Fe, Hf, La, Lu, Na, Rb, Sb, Sc, Sm, Ta, Tb, Th, Yb and Zn) in two groups of potsherds which had been excavated at two different sites of Greece, the islands of Thasos (Group A) and Delos (Group B). A good agreement for all the elements examined between the pottery specimens of Groups A and B was found. The matching in chemical composition between the stylistically related potteries of Group A (Thasos) and Group B (Delos) provides strong support for the archaeologist's hypothesis that the two groups of potsherds belong to the same major group of “melian” pottery.     

Trace elements in natural drugs determined by INAA

Natural drugs are widely used for diuretic, phlegm elimination and stomach invigoration purposes. Seventy-five of the most common remedies used by Chinese people have been subjected to trace element survey analysis by instrumental neutron activition. Within this large number of different natural products, fourteen trace elements (K, Sc, Cr, Fe, Co, Zn, Br, Rb, Cs, La, Sm, Eu, Au and Th) are commonly detected. Among these elements, Fe had the highes: concentration followed by Zn, and Rb, Sm, Eu and Au were found to have the lowest concentations. Although the three groups of natural drugs exhibit a widely different therapeutic action, the concentration ranges of the fourteen elements were very similar. While this suggests no apparent specific role for the trace elements in the drug function, parallels are drawn between the known drug related functions of Rb, Zn, Br, Fe, Co and K and the levels of elements found in the natural drugs. It is concluded that the various natural drugs also provide human benefits through supplements of essential elements such as Fe, Zn, Cr, Sc, Rb and Co.     

Instrumental neutron activation analysis of carbonatites from Homa Mountain, Kenya

Twenty eight (major and trace) elements including eight rare earth elements (REEs) in African carbonatite samples were determined by instrumental neutron activation analysis. The geochemical behavior of trace elements was studied in relation to the order of carbonatite intrusion from C1 to C4 through C2 and C3 at Homa Mountain, Kenya. The enrichment of Mn, Fe, Sr, Ba, Th, U and REE is found in the sixteen carbonatites examined in this study. The general increase in the concentrations of Na, Sc, Mn, Sb, Ba, Th, U and REE occurs from C1 to C4 through C2 and C2c, but C3 carbonatite shows a different pattern. The C3 carbonatite is extraordinarily enriched in Mn, Fe and Ba and is highly enriched in Cr, As, Sb and Th. The chondrite-normalized REE distribution pattern of the C3 carbonatite is not rich in the light REE. Strong fractionation between light and heavy REEs is found in the carbonatites, and moderate fractionation in the two alkalic igneous rock samples. In order to evaluate partitioning of REEs into carbonate, oxide and other mineral fractions, a selective chemical leaching technique on carbonatites was applied and is discussed in this study. This revised version was published online in August 2006 with corrections to the Cover Date.     

Elemental content in ground and soluble/instant coffee

The concentration of thirty-four elements in twelve coffee brands has been measured using instrumental neutron activation analysis. The samples investigated included four brands of commercially available ground coffee and eight brands of soluble/instant coffee. The elements measured were Al, As, Ba, Ca, Ce, Co, Cr, Cs, Dy, Eu, Fe, Gd, Hf, K, La, Lu, Mg, Mn, Na, Rb, Sb, Sc, Se, Sm, Sr, Ta, Tb, Th, Ti, Tm, U, V, Yb and Zn. Twenty four elements were found to be below the detection limit in one or more samples. These elements were Ce, Cr, Fe, V, As, Eu, Ba, Dy, Gd, Hf, La, Lu, Sb, Sc, Se, Sm, Sr, Ta, Tb, Th, Ti, Yb, Tm, and U.     

Determination of trace elements in Brazilian rice grains and in biological reference materials by neutron activation analysis

Instrumental neutron activation analysis was applied to the determination of the elements Na, K, Br, As, Rb, Zn, Co, Fe and Sc in Brazilian rice samples and in biological standards. Hg and Se concentrations were determined by using a simple radiochemical separation. The chemical procedure was carried out by means of distillation of Hg and Se in HBr medium and subsequent precipitation of selenium by sodium metabisulfite and mercury by thioacetamide. The accuracy of the instrumental and radiochemical methods was evaluated by means of analysis of the Reference Materials NBS-Bovine Liver, Bowen's Kale and NBS-Rice Flour.     

Behavior of some macroelements,trace elments and RE in the water-sediment system

The aim of this work was to estimate the processes of sorption or desorption which take place when water of slightly higher temperature and elevated concentrations of some elements, compared to groundwater, comes into contact with aquifer sediments under aerobic conditions. The behavior of some macro-elements, trace elements and RE in the water/sediment systems, prepared as five different granulometric fractions of the sediment, was followed by INAA, AAS and titrimetric methods, under simulated natural conditions. It was found that, for the majority of elements, desorption takes place. Opposite to this, Mg and Zn are sorbed from water on all sediment granulometric fractions. The concentration of Ca as a major cation is lingering about its initial value. Na, K, Ba, Sr, Fe, Hg, Au, Sc, Sb, U, La and Ce are desorbed from all sediment fractions. The desorption from finer sediment phase was less pronounced for Fe, Hg, Au, Sc, Sb and Ce. Sorption of some elements (like Co, Cr and Zr) on smallest sediment fraction (<90 m) appears. Sorption-desorption processes, as well as water pH changes, are time dependent, continuing for some weeks, especially in the coarse sediment system. The extents of sorption and desorption for most of the determined elements indicate that the specific surface area is not a key parameter     

Behaviour of trace element concentration in human organs in dependence of age and environment

To study the behaviour of trace elements in dependence of age and environment, samples of skin, lung, heart, aorta, kidney, liver, and brain were assayed for concentrations of Fe, Zn, Rb, Co, Cr, Se, Sc, Sb, Cs, Al and partly Eu. Nearly all element concentrations changed with progressing age, but they showed no clear correlation to either parameter assessed. The non-essential elements Sc, Sb, and Sc were increasingly concentrated in all organs except the skin. Comparing lung samples of patients from highly industrialized regions with those of lesser industrialization, the elements Sc, Al, Sb, Eu and Co were accumulated by a factor of 10 to 100. Thus the concentrations of trace elements in human organism also depends on the degree of industrialization.     

Use of INAA and ICP-MS for the assessment of trace element mass fractions in adult and geriatric prostate

The variation with age of the mass fraction of 54 trace elements (Ag, Al, As, Au, B, Be, Bi, Br, Cd, Ce, Co, Cr, Cs, Dy, Er, Eu, Fe, Ga, Gd, Hf, Hg, Ho, Ir, La, Li, Lu, Mn, Mo, Nb, Nd, Ni, Pb, Pd, Pr, Pt, Rb, Re, Sb, Sc, Se, Sm, Sn, Ta, Tb, Te, Th, Ti, Tl, Tm, U, Y, Yb, Zn, and Zr) in intact nonhyperplastic prostate of 65 healthy 21–87 year old males was investigated by instrumental neutron activation analysis with high resolution spectrometry of long-lived radionuclides and inductively coupled plasma mass spectrometry. This work revealed that there is a significant tendency for an increase in Bi, Cd, Co, Fe, Hg, Sc, Sn, Th, U, and Zn (p < 0.0014) mass fraction in normal prostate from age 21 years to the sixth decade. In the sixth to ninth decades the mass fractions of almost all chemical elements investigated in nonhyperplastic prostates were maintained at approximately stable levels. Our finding of correlation between pairs of prostatic chemical element mass fractions indicates that there is a great disturbance of prostatic chemical element relationships with increasing age.     

Determination of microelement content in the samples from the cycle of intensive poultry breeding

The results of analysis of 15 samples of meat, eggs, feed and water used in the cycle of intensive poultry breeding are given in the paper. Twenty chemical elements such as: Sm, Lu, Eu, Hf, Ce, Yb, Cr, La, Br, Sb, Cs, Sc, Fe, Co, Na, Ta, Tb, Zr, Rb and Zn have been quantitatively determined in all the samples by nondestructive neutron activation analysis. Qualitative determination of K, Ca, Ru and Au was also performed in some samples.     

Multielement analysis of green coffee and its possible use for the determination of origin

Using instrumental neutron activation analysis (INAA), graphite furnace atomic absorption spectrometry (GFAAS), flame atomic absorption spectrometry (FAAS) and combustion elemental analysis, green coffees of the Arabica species produced in crop year 1987/88 in Colombia, Costa Rica, Cuba, El Salvador, Mexico, Nicaragua, Panamá and Papua New Guinea were analysed for the elements Ba, Br, C, Ca, Co, Cr, Cu, Cs, Fe, H, K, La, Mg, Mn, N, Na, Rb, Sc, Sr and Zn. In accordance with the concentrations determined, the elements could be ranked into five groups: Sc (sub-ppb level); Br, Co, Cr, Cs and La (ppb level); Ba, Cu, Fe, Mn, Na, Rb, Sr and Zn (ppm level); Ca and Mg (%o level); and C, H, K and N (% level). On the basis of the results obtained, an attempt was made to establish the origin of the green coffee via its elemental composition. Among the investigated elements, manganese was found to be best suited as an indicator for this purpose. However, the elements C, Co, Cs, Na and Rb proved to be of interest too.