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Abstract  

In this work instrumental neutron activation analysis was applied todetermine trace elements in nail clippings and to make a comparison betweenthe results obtained from samples from healthy children and those with cysticfibrosis (CF) disease. The findings indicated that fingernails from the CFgroup present higher concentrations of Cl, Cr, K and Na than those found inthe control group. On the other hand, the lowest concentrations for Cr werefound in the CF group. For the Al, As, Co, Fe, Mg, Mn, Se and Zn elementsthere were no differences between the results obtained for the CF and controlgroups. The quality control of the results was evaluated by analysing NIST1577b Bovine Liver and NIST 1566a Oyster Tissue standard reference materials.

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Abstract  

Instrumental neutron activation analysis (INAA) was applied to evaluatethe clinical status of equines, belonging to the Military Police of SoPaulo State, by means of Cu, Fe, Mn and Zn determinations in their hair. Comparisonof the results obtained in these analyses with reference values indicatedZn deficiency in the equines, Fe is in the minimum limit and the elementsCu and Mn are within the normal range.

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Solvent extraction studies using tetracycline as a complexing agent

XV. Separation of interferences in neutron activation analysis of lanthanides in rocks

Journal of Radioanalytical and Nuclear Chemistry
Author: M. Saiki

Abstract  

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.

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Abstract  

Seventy-two leaf samples belonging to two cultivars of Cajanus cajanMillsp were analysed by instrumental neutron activation analysis (INAA). Thesamples came from plants treated with two doses of fertilizer containing eachof the following elements: B, Co, Cu, Fe, Mn, Mo, V and Zn, which were applied,individually, to the soil. The leaf samples were yielded at two differenttimes. The purpose of this paper is to elucidate the influence of each fertilizer,the dose and leaf harvest time, on the concentrations of Ca, Cu, K, Mg, Mn,Na and V, and the behavior of both cultivars in relation to the concentrationsof these elements.

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Abstract  

Instrumental neutron activation analysis (INAA) was applied to determine Ba, Br, Ca, Cl, Fe, K, Mg, Mn, Na, P, Sr and Zn in bovine and porcine rib bones. Precise results were obtained in analyses of freeze-dried cortical and trabecular bones separately, and also of whole bone ashes. Cortical tissues presented higher concentrations of Ba, Ca, Mg, Mn, Na, P, Sr and Zn than those obtained in trabecular ones. Comparisons were also made between the results obtained for bovine and porcine rib bones.

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Abstract  

The environmental changes that occurred in different periods can be identified through the increase or decrease of the concentrations of metals and other substances throughout sediment cores. The purpose of this study was to determine Al, As, Ba, Br, Cs, Eu, K, La, Mn, Sb, Sc, Sm, Th, Ti, U and V in a sediment core collected from São Paulo State South Seashore. Instrumental neutron activation analysis followed by gamma-ray spectrometry was the analytical method used. Results showed an abrupt decrease in the concentration of all elements in the 132–134 cm layer depth. This finding indicates an impact of anthropic activity.

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Abstract  

In this work, neutron activation analysis was applied to analyze the geological standard materials: GSP-1 and W-1 from USGS, GB-1 and BB-1 from the University of Bahia, Brazil and a sample of uraniferous rock. Hf was determined by instrumental method and the obtained results was shown with relative standard deviations varying from 1.1 to 14%. In the case of Zr analyses, both instrumental and radiochemical neutron activation analyses were used. The interference of154Eu radioisotope that emits -rays too close to those emitted by95Zr was eliminated by retention of Zr in an anionic exchange resin column. The contribution of uranium fission product was considered in the Zr determination by using an interference factor. Results of Zr were presented with relative standard deviations varying from 2.0 to 25.7%. More precise results were obtained by using radiochemical separation. The concentration obtained for Hf and Zr in reference materials agreed well with respective certified values or information values.

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Abstract  

Tetracycline in solution of benzyl alcohol was used as an extracting agent to separate uranium from interfering elements in the determination of uranium and of isotopic ratio235U/238U by neutron activation analysis. Separation gives a recovery of 97% for uranium and the interferences from matrices of pitchblende and monazite are eliminated.

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Solvent extraction studies using tetracycline as a complexing agent

XII. Determination of stability constants for the complexes of uranium and tetracycline

Journal of Radioanalytical and Nuclear Chemistry
Authors: M. Saiki and L. Tarenzi

Abstract  

Stability constants for uranium-tetracycline complexes were determined by the method of average number of ligands, the method of limiting values, the method of two parameters and the method of weighted least squares. Solvent extraction technique was used to obtain experimental data.

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Abstract  

Instrumental neutron activation analysis (INAA) was applied to assess element concentrations in eleven samples of mineral supplements/multivitamins acquired in drugstores and pharmacies in São Paulo city, SP, Brazil. Concentrations of Ca, Co, Cr, Cu, Fe, K, Na, Se and Zn were determined. A comparison was made between the results obtained with the labels of the mineral supplents. Certified reference materials, NIST SRM1400 Bone Ash and NIST SRM 1633b Coal Fly Ash were analyzed for quality control of the analytical results.

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