28 research outputs found

    Cooking effects on iron and proteins content of beans (Phaseolus Vulgaris L.) by GF AAS and MALDI-TOF MS

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    The effects of domestic cooking on proteins, organic compounds and Fe distribution in beans (Phaseolus vulgaris L.) were investigated. Sequential extraction with different extractant solutions (mixture of methanol and chloroform 1:2 v/v, water, 0.5 mol L-1 NaCl, 70% v/v ethanol and 0.5 mol L-1 NaOH) were used for extracting lipids, albumins, globulins, prolamins and glutelins, respectively. Iron determination by graphite furnace atomic absorption spectrometry (GF AAS), proteins by Bradford method and organic compounds by matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) were carried out in this work. High concentration of albumins, globulins and glutelins were found in raw beans, while in the cooked beans, albumins and glutelins are main proteins types. The MALDI-TOF MS spectra of raw and cooked beans revealed that the domestic cooking altered the molecular weight of the organic compounds, since that in the cooked beans were found compounds between 2 and 3.5 kDa, which were not presented in the raw beans. Besides this, in cooked beans were also observed the presence of four compounds of high molecular weight (12-16 kDa), being that in the raw grains there is only one (ca. 15.2 kDa). In raw grains is possible to observe that Fe is mainly associated to albumins, globulins and glutelins. For cooked grains, Fe is associated to albumins and globulins.Os efeitos do cozimento doméstico na distribuição de proteínas, compostos orgânicos e Fe em feijão (Phaseolus vulgaris L.) foram investigados. Extração seqüencial com diferentes agentes extratores (mistura de metanol e clorofórmio 1:2 v/v, água, NaCl, etanol e NaOH) foi usada para extrair lipídeos, albuminas, globulinas, prolaminas e glutelinas, respectivamente. A determinação de Fe por espectrometria de absorção atômica com forno de grafite (GF AAS), de proteínas pelo método de Bradford e compostos orgânicos por espectrometria de massas por tempo de vôo acoplada à ionização dessortiva de matriz por laser (MALDI-TOF MS) foram feitas nesse trabalho. Altas concentrações de albuminas, globulinas e glutelínas foram encontradas em feijão cru, enquanto que em grãos cozidos, albuminas e glutelínas foram os principais tipos de proteínas. Os espectros de MALDI-TOF MS do feijão cru e cozido revelaram que o cozimento doméstico alterou os pesos moleculares dos compostos orgânicos, uma vez que nos grãos cozidos foram encontrados compostos entre 2 e 3,5 kDa, os quais não estavam presentes no feijão cru. Além disso, no feijão cozido foi também observada a presença de quatro compostos de alto peso molecular (12-16 kDa), sendo que em grãos crus há somente um (ca.15,2 kDa). Nos grãos crus foi possível observar que Fe está principalmente associado a albuminas, globulinas e glutelínas. Para os grãos cozidos, Fe está presente em alta concentração em albuminas e globulinas.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Universidade Federal de São Paulo (UNIFESP)Universidade de São Paulo Instituto de Química Departamento de Química FundamentalUNIFESPSciEL

    Operação em ambiente móvel baseado em modelo de mercado

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    Projecto Final para obtenção do grau de Mestre em Engenharia Informática e de ComputadoresA evolução das tecnologias associadas à Internet (a que se assiste continuamente) está a modificar a forma como a informação é produzida e armazenada permitindo o seu acesso em qualquer local. As empresas pretendem que os colaboradores, que realizam trabalho no terreno, enviem a informação das suas tarefas de forma rápida de modo a ser registada nos sistemas informáticos. O pressuposto essencial para a realização dessas operações é a existência de conectividade. Apesar do acesso sem-fio à Internet ser amplamente utilizado, existem situações onde os utilizadores estão privados dessa ligação. Este projeto apresenta modelos para o desenvolvimento de aplicações WebOffline. O Web-Offline é um conceito enquadrado nas tecnologias de Internet que permite o acesso a um Website através do Browser sem a necessidade de uma ligação permanente à rede global. Neste sentido foi implementada uma aplicação com estas características que permite aos utilizadores realizarem as suas tarefas sem uma dependência contínua de conectividade. As tarefas são disponibilizadas aos utilizadores através de Backoffice. As escolhas das tarefas são negociadas, pelos utilizadores entre si, através de um mecanismo de leilão. A aplicação implementada foi testada por diversos utilizadores de forma a avaliar a sua usabilidade. Os resultados obtidos demostraram uma recetividade positiva por parte dos utilizadores.Abstract: Currently, the evolution of new Internet related technologies (which is continually increasing) is constantly changing the way information is produced and stored allowing easy access worldwide. Workers are encouraged by companies to send the information regarding its tasks quickly and efficiently, in order to be properly stored in the computer system. One of the major and essential prerequisite for the accomplishment of these operations is the existence of connectivity. However, despite the extensive access to wireless Internet, in some situations users are deprived of this connection. The main goal of this project is to present alternative models for the development of applications offline (Web-Offline). The Web-Offline is a new concept in the range of Internet technologies which allow easy access to a Website through the Browser without the need for a permanent connection to the global network. Therefore, we implemented an application available via Backoffice, which allows users to perform their tasks without the need for continued connectivity. Tasks selections are negotiated between users through an auction mechanism. The application has been tested and implemented by different users in order to evaluate its usability. The results demonstrated a very positive reception by the users

    Association of dental enamel lead levels with risk factors for environmental exposure

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    OBJECTIVE: To analyze household risk factors associated with high lead levels in surface dental enamel. METHODS: A cross-sectional study was conducted with 160 Brazilian adolescents aged 14-18 years living in poor neighborhoods in the city of Bauru, southeastern Brazil, from August to December 2008. Body lead concentrations were assessed in surface dental enamel acid-etch microbiopsies. Dental enamel lead levels were measured by graphite furnace atomic absorption spectrometry and phosphorus levels were measured by inductively coupled plasma optical emission spectrometry. The parents answered a questionnaire about their children's potential early (05 years old) exposure to well-known lead sources. Logistic regression was used to identify associations between dental enamel lead levels and each environmental risk factor studied. Social and familial covariables were included in the models. RESULTS: The results suggest that the adolescents studied were exposed to lead sources during their first years of life. Risk factors associated with high dental enamel lead levels were living in or close to a contaminated area (OR = 4.49; 95% CI: 1.69;11.97); and member of the household worked in the manufacturing of paints, paint pigments, ceramics or batteries (OR = 3.43; 95% CI: 1.31;9.00). Home-based use of lead-glazed ceramics, low-quality pirated toys, anticorrosive paint on gates and/or sale of used car batteries (OR = 1.31; 95% CI: 0.56;3.03) and smoking (OR = 1.66; 95% CI: 0.52;5.28) were not found to be associated with high dental enamel lead levels. CONCLUSIONS: Surface dental enamel can be used as a marker of past environmental exposure to lead and lead concentrations detected are associated to well-known sources of lead contamination.OBJETIVO: Analizar factores de riesgo en el ambiente domiciliar asociados con altos niveles de plomo en el esmalte dental superficial. MÉTODOS: Se realizó estudio transversal con 160 adolescentes brasileros (14 a 18 años), residentes en urbanizaciones pobres del municipio de Bauru, SP, de agosto a diciembre de 2008. La concentración de plomo en el esmalte dental fue evaluada por micro biopsias ácidas del esmalte dental superficial, cuantificada por espectrometría de absorción atómica con horno de grafito y la concentración de fósforo fue medida por espectrometría de absorción óptica con plasma inductivamente acoplado. Los padres de los adolescentes respondieron a cuestionario sobre posible exposición previa (5 primeros años de vida del adolescente) al plomo producto de fuentes de contaminación bien conocidas. Se usó regresión logística para identificar asociaciones entre concentración de plomo en el esmalte y factores de riesgo ambientales. Covariables familiares y sociales fueron incluidas en los modelos. RESULTADOS: Los resultados sugieren que los jóvenes evaluados fueron expuestos a fuentes de plomo durante sus primeros años de vida. Los factores de riesgo asociados con el resultado fueron residir en área contaminada por plomo o en sus proximidades (OR=4,49; IC 95%: 1,69;11,97) y haber convivido, en el mismo domicilio, con persona que trabajaba en fábrica de tintas, pigmentos, cerámicas o baterías (OR= 3,43; IC 95%: 1,31;9,00). Haber usado, en casa, cerámica vitrificada, juegos de baja calidad o piratas, haber aplicado zircón en portones de hierro sin cobertura esmaltada o almacenar baterías de carro usadas en la residencia (OR= 1,31; IC 95%: 0,56-3,03) y hábito de fumar no fueron asociados con altas concentraciones de plomo en el esmalte dental (OR=1,66; IC 95%: 0,52;5,28). CONCLUSIONES: El esmalte dental superficial puede ser utilizado como marcador de exposición ambiental pasada al plomo y las concentraciones encontradas de dicho metal están relacionadas con fuentes bien conocidas de contaminación por plomo.OBJETIVO: Analisar fatores de risco no ambiente domiciliar associados com altos níveis de chumbo no esmalte dentário superficial. MÉTODOS: Estudo transversal conduzido com 160 adolescentes brasileiros (14 a 18 anos), residentes em bairros pobres do município de Bauru, SP, de agosto a dezembro de 2008. A concentração de chumbo no esmalte dentário foi avaliada por microbiópsias ácidas do esmalte dentário superficial, quantificada por espectrometria de absorção atômica com forno de grafite e a concentração de fósforo foi medida por espectrometria de absorção óptica com plasma indutivamente acoplado. Os pais dos adolescentes responderam a questionário sobre possível exposição prévia (cinco primeiros anos de vida do adolescente) a chumbo decorrente de fontes de contaminação bem conhecidas. Usou-se regressão logística para identificar associações entre concentração de chumbo no esmalte e fatores de risco ambientais. Covariáveis familiares e sociais foram incluídas nos modelos. RESULTADOS: Os resultados sugerem que os jovens avaliados foram expostos a fontes de chumbo durante seus primeiros anos de vida. Os fatores de risco associados com o desfecho foram residir em área contaminada por chumbo ou nas suas proximidades (OR = 4,49; IC 95%: 1,69;11,97) e ter convivido, no mesmo domicílio, com pessoa que trabalhava em fábrica de tintas, pigmentos, cerâmicas ou baterias (OR = 3,43; IC 95%: 1,31;9,00). Ter usado, em casa, cerâmica vitrificada, brinquedos de baixa qualidade ou piratas, ter aplicado zarcão em portões de ferro sem cobertura esmaltada ou armazenar baterias de carro usadas na residência (OR = 1,31; IC 95%: 0,56;3,03) e hábito de fumar não foram associados com altas concentrações de chumbo no esmalte dentário (OR = 1,66; IC 95%: 0,52;5,28). CONCLUSÕES: O esmalte dentário superficial pode ser utilizado como marcador de exposição ambiental passada ao chumbo e as concentrações encontradas desse metal estão ligadas a fontes bem conhecidas de contaminação por chumbo

    Simultaneous determination of Cr, Fe, Ni and V in crude oil by emulsion sampling graphite furnace atomic absorption spectrometry

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    In this work a simple and reliable method for the simultaneous determination of Cr, Fe, Ni and V in crude oil, using emulsion sampling graphite furnace atomic absorption spectrometry is proposed. Under the best conditions, sample masses around 50 mg were weighed in polypropylene tubes and emulsified in a mixture of 0.5% (v v(-1)) hexane + 6% (m v(-1)) Triton X-100 (R). Considering the compromised conditions, the pyrolysis an atomization temperatures for the simultaneous determination of Cr, Fe, Ni and V were 1400 degrees C and 2500 degrees C, respectively. Aliquots of 20 mu L of reference solution and sample emulsion were co-injected into the graphite tube with 10 mu L of 1.0 g L(-1) Mg(NO(3))(2) as chemical modifier. The detection limits (n = 10, 3 sigma) and characteristic masses were, respectively: 0.07 mu g g(-1) and 19 pg for Cr; 2.15 mu g g(-1) and 31 pg for Fe; 1.25 mu g g(-1) and 44 pg for Ni; and 1.15 mu g g(-1) and 149 pg for V. The reliability of the proposed method was checked by fuel oil Standard Reference Material (SRMTriton X-100 (R) 1634c - NIST) analysis. The concentrations found presented no statistical differences compared to the certified values at 95% confidence level.National Institute of Advanced Analytical Science and Technology (INCTAA)[573894/2008-6]National Institute of Advanced Analytical Science and Technology (INCTAA)[2008/57808-1]Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP)Conselho Nacional de Desenvolvimento Cientifico c Tecnologico (CNPq)Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior (CAPES

    Method for cadmium and lead longitudinal profiles determination in hair by solid sampling graphite furnace atomic absorption spectrometry

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    This paper describes methods for the direct determination of Cd and Pb in hair segments (c.a. 5 mm similar to 80 mu g) by solid sampling graphite furnace atomic absorption spectrometry, becoming possible longitudinal profiles in a single strand of hair. To distinguish endogenous and exogenous content. strands of hair were washed by using two different procedures: IAEA protocol (acetone + water + acetone) and the combination of IAEA protocol with HCl washing (acetone + water + acetone + 0.1 mol l(-1) HCl). The concentration of Cd and Pb increased from the root Until the tip of hair washed according to IAEA protocol. However, when the strand of hair was washed using the combination of IAEA protocol and 0.1 mol l(-1) HCl, Cd concentrations decreased in all segments, and Pb concentrations decreased drastically near to the root (5 to 12 mm) and was systematically higher ill the end. The proposed method showed to be useful to assess the temporal variation to Cd and Pb exposure and call be Used for toxicological and environmental investigations. The limits of detection were 2.8 ng g(-1) for Cd and 40 ng g(-1) for Pb. The characteristic masses based oil integrated absorbance were 2.4 pg for Cd and 22 pg for Pb.Fundacao de Amparo a pesquisa do Estado de Sao Paulo (FAPESP)Conselho Nacional de Desenvolvimento Cientifico eTechologico (CNPq

    Feasibility of using in situ fusion for the determination of Co, Cr and Mn in Portland cement by direct solid sampling graphite furnace atomic absorption spectrometry

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    In situ fusion on the boat-type graphite platform has been used as a sample pretreatment for the direct determination of Co, Cr and Mn in Portland cement by solid sampling graphite furnace atomic absorption spectrometry (SS-GF AAS). The 3-field Zeeman technique was adopted for background correction to decrease the sensitivity during measurements. This strategy allowed working with up to 200 mu g of sample. The in situ fusion was accomplished using 10 mu L of a flux mixture 4.0% m/v Na(2)CO(3) + 4.0% m/v ZnO + 0.1% m/v Triton (R) X-100 added over the cement sample and heated at 800 degrees C for 20 s. The resulting mould was completely dissolved with 10 mu L of 0.1% m/v HNO(3). Limits of detection were 0.11 mu g g(-1) for Co, 1.1 mu g g(-1) for Cr and 1.9 mu g g(-1) for Mn. The accuracy of the proposed method has been evaluated by the analysis of certified reference materials. The values found presented no statistically significant differences compared to the certified values (Student`s t-test, p<0.05). In general, the relative standard deviation was lower than 12% (n = 5). (C) 2009 Elsevier B.V. All rights reserved

    Análise direta de sólidos por espectrometria de absorção atômica com atomização em forno de grafite: uma revisão Solid sampling graphite furnace atomic absorption spectrometry: a review

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    <abstract language="eng">This is a review of direct analysis using solid sampling graphite furnace atomic absorption spectrometry. Greater emphasis is dedicated to sample preparation, sample homogeneity, calibration and its application to microanalysis and micro-homogeneity studies. The main advantages and some difficulties related to the applicability of this technique are discussed. A literature search on the application of solid sampling graphite furnace atomic absorption spectrometry in trace element determination in many kinds of samples, including biological, clinical, technological and environmental ones, is also presented

    Elemental analysis of nuts and seeds by axially viewed ICP OES

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    A method for the multi-elemental determination of metals (Al, Ba, Ca, Cu, Fe, K, Mg, Mn, Sr and Zn), metalloids (B and Si), and non-metals (Cl, P and 5) in the babassu nut and mesocarp, sapucaia nut, coconut pulp, cupuassu pulp and seed, and cashew nut by axially viewed inductively coupled plasma optical emission spectrometry is presented. A diluted oxidant mixture (2 ml HNO(3) + 1 ml H(2)O(2) + 3 ml H(2)O) was used to achieve the complete decomposition of the organic matrix in a closed-vessel microwave oven. The accuracy of the entire proposed method was confirmed by standard reference material analysis (peach leaves-NIST SRM1547). The certified values showed a good agreement at a 95% confidence limit (Student`s t-test). The average RSD for repeatability of calibration solutions measurements were in the range of 1.1-6.7%. Limits of quantification (LOQ = 10 x LOD) were in the level of 0.00072-0.0532 mg/l. The macro and micronutrient ranges in the different nuts and seeds did not exceed the dietary reference intake (DRI), except for Mn in the babassu nut. (C) 2010 Published by Elsevier Ltd.Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP

    Bismuth Modified Gold Microelectrode for Pb(II) Determination in Wine Using Alkaline Medium

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    Electrodeposition of bismuth on gold microelectrodes for determination of Pb(II) by square wave anodic stripping voltammetry (SWASV) was accomplished by an in situ procedure in alkaline solution. A linear calibration plot for Pb(II) in the concentration range 40 to 6700 nmol L(-1) (r=0.998) was obtained, the detection limit was found to be 12.5 nmol L(-1) (S/N = 3) and the relative standard deviation in Solutions containing 1 mu mol L(-1) Pb(II) was 4% (n = 12). The analytical performance of the proposed sensor wits tested by measuring the Pb(II) concentration in a wine sample. The result Was in good agreement with the one obtained by GFAAS.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Fundacao de Apoio a Pesquisa do Estado de Sao Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq
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