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Abstract  

Thermal and epithermal neutron activation analysis techniques were used to analyze 27 Teflon air filters which were exposed to ambient air in Lisbon, Portugal, in February 2007. Tin was detected which is strongly suggestive of an anthropogenic source. Arsenic, antimony and copper were shown to be highly correlated, which is also suggestive of anthropogenic pollution. Trace element analysis of short- and medium-lived isotopes was performed yielding concentration information of various elements. Analytical sensitivities were enhanced using a Compton suppression system. Enrichment factor analysis shows that arsenic, tin, zinc, copper and antimony are at elevated concentrations in the Lisbon atmosphere.

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Abstract  

Osmotically controlled and oral drug delivery systems utilize osmotic pressure for controlled delivery of active agent(s). Drug delivery from these systems, to a large extent, is independent of the physiological factors of the gastrointestinal tract and these systems can be utilized for systemic as well as targeted delivery of drugs. We apply the thermal methods and IR spectroscopy to study compatibility between atenolol and several excipients usually found in the osmotic systems formulations (Polyethylene oxide, MW 3350, 100000, 200000 and 5000000; HPMC K4000, magnesium stearate and cellulose acetate. Cellulose acetate, HPMC K4000 and magnesium stearate have essentially no interaction with atenolol otherwise all Polyethylene oxide excipients modifies significantly the drug melting point indicating some extend of interaction.

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Summary  

We have employed Compton supression neutron activation analysis in conjunction with thermal and epithermal neutrons to detemine trace elements in airborne particulate matter in Lisbon, Portugal. As a result of the proximity of ocean marine, elements such as sodium and chlorine can signficantly decrease the analytical sensitivities of many elements of interest due ot the high backgrounds arising from 38Cl and 24Na. Compton suppression has resulted in the increase of the analytical sensitivities using thermal neutrons of Al, Ba, Ce, Cr, Cu, Ni, Rb, Se, Th, Ti, V, and Zn. The use of Compton suppression and epithermal neutrons significantly reduced the detection limits for As, I, K, Si, and W, while the utilization of solely epithermal neutrons improved the analyses of In.

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Abstract  

A numerical procedure is given to correct for the interference of U in the determination of the light rare earths, Zr, and Ru. The corresponding interference factors were calculated and their values compared with experimental results. The agreement is favourable in most cases.

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Abstract  

This study deals with the influence of the exposure conditions on biological uptake, by looking into concentrations of Ni and V in lichen thalli and tree bark after continuous and discontinuous field trials at littoral sites impacted by anthropogenic emissions. Biomonitors were assessed by k 0-INAA and AAS. Correlations at Sines are more apparent than at Viana or Lisboa. When data from all sites are pooled, V shows correlations for practically every situation while Ni shows none, which may indicate a dissimilar uptake mechanism for each element. At Sines, V/Ni ratios reach values that comply with emissions from oil-related industries.

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Abstract  

Instrumental neutron activation, atomic absorption spectroscopy and conventional methods of analysis were used on eight different silicate rocks and two minerals. Trace elements and major constituents were determined. It was considered that the methods should be regarded as complementary analytical techniques.

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Abstract  

The neutron activation analysis (NAA) was applied to the multielement analysis of the mediterranean fruit fly, Ceratitis capitata Wied., taken from a stock produced at the Tropical Scientific Research Institut (IICT) in Lisbon, and to its artificial food. Dry samples were irradiated in the OSIRIS reactor, within a work performed at the Laboratoire d'Analyse par Activation Pierre Süe (CEA/CEN-Saclay). The contents of Ca, K, Mg, Cl, Na, Fe, Zn, Al, Mn, Ba, Rb, Br, Co and Cs for the cases of Ceratitis capitata Wied. eggs, larvae, pupae, males and females and of its artificial food are reported.

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Abstract  

18F fluoride ion is produced by bombarding18O enriched water using an 11 MeV negative ion Radioisotope Delivery System (RDS-112) cyclotron by18O(p,n)18F reaction. During the synthesis of18F-FDG, a gaseous effluent containing18F is released. To quantitate the loss of18F during the synthesis, the18F activity at the end of bombardment delivered to chemical process control unit (CPCU), the amount of18F-FDG produced, the residual activity in CPCU, the activity trapped in charcoal filter, reaction vessels, cartridge and resin column were measured. A dose calibrator was used to assay total18F delivered to the CPCU and FDG produced. All other measurements were with a calibrated ionization chamber in a fixed geometry. The amount of gaseous18F released was calculated. For routine productions, conversion of18F into FDG was 46.0±4.0%. In six production runs without a charcoal filter, the mean gaseous release of18F was 10.6±1.0%. With an activated charcoal filter retrofitted to the exhaust of the CPCU, then mean gaseous18F activity released was 1.2±1.2%. The residual activity in the synthesis unit was 12.9±3.5%. The remaining activity i.e. 33.1±4.2%, was in the reaction vessels, cartridges and in the resin column. The efficiency of a charcoal filter for trapping18F gaseous effluent during synthesis was found to be >99.0%.

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Abstract  

This paper presents the reactions of synthesis between the ligand sodium diphenylamine-4-sulfonate and the lanthanum(III) chloride hydrated. The compounds (LaCl3)2(C12H10NSO3Na)32(CH3CH2OH) (A) and (LaCl3)(C12H10NSO3Na)(CH3CH2OH)12H2O (B) were obtained using the solvents ethanol and methanol (synthesis A) and ethanol and water (synthesis B). The produced compounds and the ligand were characterized by thermogravimetric and differential thermogravimetric analysis, IR spectroscopy and elemental analysis of sodium, carbon, hydrogen, nitrogen, sulfur, chlorine and lanthanum, whereas the residues from thermal decomposition were investigated by X-ray diffractometry.

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Journal of Radioanalytical and Nuclear Chemistry
Authors: C. Galinha, M. Freitas, A. Pacheco, J. Kameník, J. Kučera, H. Anawar, J. Coutinho, B. Maçãs, and A. Almeida

Abstract  

Selenium (Se) is an essential micronutrient for human health but it is deficient in at least 1 billion people around the globe. Cereals are by far the most significant agricultural crops, not only on a gross tonnage basis, but also by what they represent in terms of energy supply and dietary intake for human nutrition worldwide. Portugal is no exception to such pattern. The Portuguese situation is difficult to assess though, due to scarce information and lack of consistent studies on the subject. In these terms, the Se status of major cereals and their cultivation soils are dealt with herein. Two species of wheat–bread and durum wheat–were sown at the end of November 2009, and then sampled in different growth stages. Rye was collected during harvest season, and cultivation soils were analyzed as well. Se results were within the range of: 100–225 ng g−1 for soils; 3–55 ng g−1 for durum wheat; 6–80 ng g−1 for bread wheat; and 4–30 ng g−1 for rye. Accuracy of the RNAA procedure was proved by analysis of reference materials NIST-SRM 1515 and NIST-SRM 8433.

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