X-ray fluorescence determination of adsorbed copper on activated charcoal after glycerin complexation

X-This work shows an alternative method to copper determination by X-Ray Fluorescence (XRF). Since copper concentration in natural waters is not enough to reach XRF detection limit, a liquid-solid preconcentration procedure was proposed. Glycerin was used to complex the metal increasing its adsorption on activated charcoal. The solid phase was used to XRF determination. Several parameters were evaluated, such as, the complexation pH, the charcoal adsorption limit and the glycerin concentration. The interferences are lead and bismuth and the sensitivities decreased in the order Cu2+, Bi3+ and Pb2+. The advantages of the method are its simplicity, low cost and low spectral interference.434436Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

Energy dispersive X-ray fluorescence applied to mapping of tree stems in Campinas, São Paulo

Dendrochemistry is based on the determination of elements retained in tree rings, which can be useful to characterize environmental occurrences. This work shows elemental mappings obtained by EDXRF of the cross section of a tree stem. The tree is originated from a polluted area in Campinas, São Paulo. Some profiles, as the sulfur one, show variations that can be attributed to external contributions, whereas the silicon one can be inferred to a protection defense natural mechanism. Besides being simultaneous and multielementar, the main advantages here are its performance through a non-destructive sample treatment and the ease of operation of XRF equipments.24072411Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

Estudo da influência dos particulados no fenômeno de agregação dos asfaltenos por espectrometria de varredura óptica

The processing of national petroleums causes many operational problems due to the asphaltene aggregation phenomena. To evaluate the behavior of these phenomena, a study based on optical scan technique was carried out to understand the behavior of pure oils and their mixtures. The evaluation according to criteria established by ASTM D7061-06¹ gives a result of asphaltene flocculation of according to the separability number. In this study, the aspects related to the existence of colloidal forms of peptized asphaltenes in distinct solvents present in petroleums can cause changes in the kinetics of asphaltene flocculation

Study of the influence of the particulate in aggregation phenomenon of the asphaltenes by optical scanning spectrometry

The processing of national petroleums causes many operational problems due to the asphaltene aggregation phenomena. To evaluate the behavior of these phenomena, a study based on optical scan technique was carried out to understand the behavior of pure oils and their mixtures. The evaluation according to criteria established by ASTM D7061-06¹ gives a result of asphaltene flocculation of according to the separability number. In this study, the aspects related to the existence of colloidal forms of peptized asphaltenes in distinct solvents present in petroleums can cause changes in the kinetics of asphaltene flocculation.424429Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP

Neutron activation analysis and X-ray Rayleigh and Raman scattering of hair and nail clippings as noninvasive bioindicators for Cu liver status in Labrador Retrievers

The heritability of chronic hepatitis in the Labrador Retriever is studied with the aim of identifying the related gene mutation. Identification of cases and controls is largely based on instrumental neutron activation analysis (INAA) Cu determination in liver biopsies. The burden for these companion animals may be reduced if nail clippings and hair (fur) could serve as a noninvasive indicator for the hepatic Cu concentrations. No correlation was found between hepatic Cu concentrations and Cu concentrations in hair and nail samples. However, hair and nail samples were also analyzed by X-ray tube excitation, taking advantage of the X-ray Compton, Rayleigh, and Raman scattering which reflects the organic components such as the type of melanin. Principal component analysis provided first indications that some differentiation between healthy and sick dogs could indeed be obtained from hair and nail analysis

Landmarks in the history of radioactivity and current tendencies

The first days of radioactivity, the discoveries of X-rays, radioactivity, of alpha- and beta- particles and gamma- radiation, of new radioactive elements, of artificial radioactivity, the neutron and positron and nuclear fission are reviewed as well as several adverse historical marks, such as the Manhattan project and some nuclear and radiological accidents. Nuclear energy generation in Brazil and the world, as an alternative to minimize environmental problems, is discussed, as are the medicinal, industrial and food applications of ionizing radiation. The text leads the reader to reflect on the subject and to consider its various aspects with scientific and technological maturity.839

Determinação de traços de mercurio em fluxo continuo, por emissão atomica em plasma de helio de baixa potencia

Orientador : João Carlos de AndradeTese (doutorado) - Universidade Estadual de Campinas, Instituto de QuimicaDoutorad

X-ray fluorescence determination of adsorbed copper on activated charcoal after glycerin complexation

X-This work shows an alternative method to copper determination by X-Ray Fluorescence (XRF). Since copper concentration in natural waters is not enough to reach XRF detection limit, a liquid-solid preconcentration procedure was proposed. Glycerin was used to complex the metal increasing its adsorption on activated charcoal. The solid phase was used to XRF determination. Several parameters were evaluated, such as, the complexation pH, the charcoal adsorption limit and the glycerin concentration. The interferences are lead and bismuth and the sensitivities decreased in the order Cu2+, Bi3+ and Pb2+. The advantages of the method are its simplicity, low cost and low spectral interference