Volume 37, Número 5, 2014

ISSN:0100-4042ISSN:1678-7064 on line

776 Avaliação de diferentes métodos para a determinação de co-bre em óleo mineral isolante por espectrometria de absorção atômica com forno de grafite

Luiz F. S. Caldas, Carlos E. R. de Paula, Daniel M. Brum, Fábio G. Lepri e Ricardo J. Cassella

Graphical AbstractAbsorbance signals obtained in the copper measurement by GFAAS in the extract obtained from extraction induced by emulsion breaking (A), in the direct introduction of emulsion (B) and in the extract obtained from the re-extraction of the oil (C).

770 Análise espacial e quimiométrica da distribuição de espécies metálicas em solos alagáveis e não alagáveis da Bacia do Médio Rio Negro, Amazônia

Mirela C. de O. Cordovil, André G. R. Mendonça, Wander G. Botero, Ademir dos Santos, Julio C. Rocha, Kaline de Mello, Rogério H. Toppa e Luciana C. de Oliveira

Graphical AbstractSpatial and chemometric analysis of the distribution of metal species in soils of the Basin Middle Rio Negro, showed that proximity to urban areas is probably a variable that influences the organic matter content and metal species in flooded and non-flooded areas.

766 Tratamentos térmico e químico para remoção de óxidos alcalinos de cinzas de capim elefante

Erika Y. Nakanishi, Ernesto Villar-Cociña, Sérgio F. Santos, Michelle S. Rodrigues, Pedro S. Pinto e Holmer Savastano Junior

Graphical AbstractThe analysis evidenced that the chemical treatment was more efficient to remove the potassium oxide. The pozzolanic activity test and the kinetic parameters for the EGAas indicated that this ash is adequate for cement based composite.

761 Catálise básica usando sílica mesoporosa estabilizada por acrilatos encapsulados

Fernanda T. Cruz e Dilson Cardoso

Graphical AbstractThe figure shows the initial formation of the micelle followed by the encapsulation of the monomer and finally its polymerization in the interior of the micelle by UV radiation.

Artigo

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789 Avaliação da atividade antimicrobiana de soluções de flumequina submetidas aos processos eletroquímico e foto--eletroquímico

Caio Rodrigues-Silva, Milena G. Maniero e José R. Guimarães

Graphical AbstractElectrochemical and photo-electrochemical processes were used to degrade flumequine in aqueous solution: the drug concentration and the antimicrobial activity were reduced throughout the reaction time, and an intermediate with m/z 244 was identified.

783 Avaliação da remoção de fármacos e de desreguladores endócrinos em águas de abastecimento por clarificação em escala de bancada

Diego R. S. Lima, Robson J. C. F. Afonso, Marcelo Libânio e Sérgio F. de Aquino

Graphical AbstractThis paper evidences the low and moderate removal efficiency of emerging microcontaminants by clarification treatment in natural waters with low and high turbidity using aluminum sulfate (SA) and polyaluminium chloride (PAC) as the coagulant.

796 A new approach to evaluate immobilization of b-galactosidase on Eupergit® C: structural, kinetic, and thermal characteriza-tion

Anna R. C. Braga, Marceli F. Silva, José V. Oliveira, Helen Treichel and Susana J. Kalil

Graphical AbstractThis study assessed the activity of an immobilized enzyme to determine its potential utilization after the immobilization process.

804 Removal of Pb(II) ions and malachite green dye from was-tewater by activated carbon produced from lemon peel

Sayed Z. Mohammadi, Mohammad A. Karimi, Sayedeh N. Yazdy, Tayebeh Shamspur and Hooshang Hamidian

Graphical AbstractA high-surface area activated carbon was prepared by chemical activation of lemon peel. The maximum adsorption capacity of Malachite green dye and Pb(II) ions were found to be 66.67 and 90.91 mg g-1, respectively, at room temperature.

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816 Influência de parâmetros de processo na obtenção de sílica a partir de cinza da casca de arroz pela ação de Fusarium oxysporum

Tatiana G. Pineda-Vásquez, Mabel T. B. e Silva, Carlos H. L. Soares e Dachamir Hotza

Graphical AbstractThe fungus Fusarium oxysporum was used for the biotransformation of rice husk ash into silica nanoparticles. Glucose concentration, fermentation time and pH have an effect on the production of extracellular enzymes such as β-glucosidase and peroxidase.

810 Análise exploratória aplicada a espectros de reflexão total atenuada no infravermelho com transformada de Fourier (ATR-FTIR) de blendas de biodiesel/diesel

Carla F. C. Ruschel, Chun T. Huang, Dimitrios Samios e Marco F. Ferrão

Graphical AbstractThe exploratory analysis of the spectral data obtained by FTIR-HATR, extracted the information from different chemical blends biodiesel/diesel, allowing to identify the different concentrations, different transesterification routes and raw materials used in the process.

821 Phenolic composition and antioxidant properties of Brazilian honeys

Fernanda B. Salgueiro, Aline F. Lira, Victor M. Rumjanek and Rosane N. Castro

Graphical AbstractPolyphenol-rich honey extracts prepared with Amberlite XAD-4 polymeric resin were analyzed using HPLC coupled with multivariate statistical analysis to detect possible biomarkers of their floral origin.

827 Use of multivariate experimental designs for optimizing the reductive degradation of an azo dye in the presence of redox mediators

Diego R. S. Lima, Bruno E. L. Baeta, Gilmare A. da Silva, Silvana Q. Silva e Sérgio F. Aquino

Graphical AbstractIn this study, we demonstrate the anaerobic extracellular reduction of an azo dye. Color removal was enhanced by the presence of yeast extract, which is an inexpensive source of the redox mediator riboflavin, and the optimized reductive conditions were established by multivariate experimental design.

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839 Biodegradable nanoparticles obtained from zein as a drug delivery system for terpinen-4-ol

Vanderléia G. Marini, Silvia M. Martelli, Clarice F. Zornio,

Thiago Caon, Cláudia M. O. Simões, Gustavo A. Micke,

Marcone A. L. de Oliveira, Vanderlei G. Machado and Valdir Soldi

Graphical AbstractNanoparticles prepared from zein were used for encapsulation and release of terpinen-4-ol, a therapeutic agent for the treatment of melanoma. The optimized system has the potential for use in anti-melanoma therapy considering that it offers sustained delivery.

833 DFT study on low molecular weight α,α-ditert-butyl-4H-cyclopenta[2,1-b,3;4-b’]dithiophene and α,α-ditert-butyl-4H-cyclopenta[2,1-b,3;4-b’]dithiophene s-oxide bridged derivatives

Banjo Semire and Olusegun A. Odunola

Graphical AbstractThe frontier orbital energy of α,α-ditert-butyl-4H-cyclopenta[2,1-b,3;4-b’]dithiophene (DBDT) and α,α-ditert-butyl-5H-cyclopenta[2,1-b,3;4-b’]dithiophene S-oxide (DBDTO) bridged with CH2, C=S, and C=O revealed that the C=S and C=O bridge destabilized the HOMO, lowering the band gap.

844 Caracterização físico-química do óleo essencial da Siparuna guianensis Aublet

Augustus C. F. Portella, Marilda Munaro, Sergio D. Ascêncio, Chrystian de A. Siqueira, Talita P. de S. Ferreira e Raimundo W. de S. Aguiar

Graphical AbstractThe essential oil of Siparuna guinansis Aublet, a characteristic plant of the Brazilian cerrado, has medicinal applications and ethnobotany. Infrared spectroscopy is one of the methods used to qualitatively characterize the molecular structure of compounds for the development of new products.

850 Advances in ethanol reforming for the production of hydro-gen

Laura Guerrero, Sebastián Castilla and Martha Cobo

Graphical AbstractThis paper reviewed the following regarding the steam reforming of ethanol: new catalyst design, catalyst stability and new technologies in the reactor configuration.

Revisão

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868 Ocorrência e degradação de quinolonas por processos oxi-dativos avançados

Caio Rodrigues-Silva, Milena G. Maniero, Marcela S. Peres e José R. Guimarães

Graphical AbstractA review on the occurrence of quinolones in environmental matrices, the degradation of these compounds by conventional and advanced oxidation processes, including a discussion about intermediates and residual antimicrobial activity, was conducted.

857 Produção de hidrogênio via fermentação anaeróbia – aspectos gerais e possibilidade de utilização de resíduos agroindus-triais brasileiros

Lívian R. V. de Sá, Magali C. Cammarota e Viridiana S. Ferreira-Leitão

Graphical AbstractThe use of renewables for obtaining energy and chemicals is a prerequisite for sustainability and Brazilian agro-industrial wastes are still unexplored, but they open up infinite possibilities, which include the hydrogen production by anaerobic fermentation.

886 A química de coordenação e a produção de combustíveis solares

Sinval F. Sousa e Antonio O. T. Patrocinio

Graphical AbstractThe efficient conversion of solar energy into fuels (artificial photosynthesis) through simple systems is one of the great scientific challenges today. The present study shows how the coordination chemistry can be used to generate clean energy from the sun.

896 Equilibrium studies of 2,2’-(5-bromo-6-methylpyrimi-dine-2,4-diyl)bis(azanediyl)dipropanoic acid with some transition-metal ions in aqueous solution

Seyed A. A. Sajadi, Ghodsieh Bagherzadeh, Marzieh Khaleghian, Maryam Mirbagheri and Hosein Safaie

Graphical AbstractThe stability constants of the 1:1 complexes formed between M2+ (M2+: Mn2+, Ni2+, Cu2+, or Cd2+) and BMADA2− (BMADA: 2,2′-(5-bromo-6-methylpyrimidine-2,4 diyl)bis(azanediyl)dipropanoic acid) were determined by potentiometric pH titration in aqueous solution. In the M–BMADA complexes, the M ion is able to form a macrochelate via the pyrimidine group of BMADA.

Nota Técnica

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908 A significação conceitual pela escrita e reescrita orientada em aulas de Química

Judite S. Wenzel e Otavio A. Maldaner

Graphical AbstractThe image shows the interactive process mediated by the language. The people involved in the pedagogical relation interact by the language use, which acts as a mediator in the knowledge meaning process in the classroom.

900 Determinação de resíduos de agrotóxicos em leite bovino empregando método QuEChERS modificado e GC-MS/MS

Danieli D. Bandeira, Juliana S. Munaretto, Tiele M. Rizzetti, Giovana Ferronato, Osmar D. Prestes, Manoel L. Martins, Renato Zanella e Martha B. Adaime

Graphical AbstractGC-MS/MS and QuEChERS based method were employed to optimise a rapid and easy sample preparation method for the determination of different pesticide residues in milk. This method could be implemented in many laboratories to reduce inspection time and cost.

915 Resgatando um método eficiente para determinação do ponto de ebulição de substâncias orgânicas: percolador versus Siwoloboff

Flaviana R. F. Dias, Wanderson A. da Silva, Vinícius R. Campos, Anna C. Cunha, Vitor F. Ferreira e Nelson Â. de Souza

Graphical AbstractThe use of percolator is more accurate method than the Siwoloboff’s technique for determining the boiling point of organic compounds.

919 O que sabemos sobre os primeiros livros didáticos brasileiros para o ensino de Química

Rafael C. Mori e Antonio A. da S. Curvelo

Graphical AbstractA paper about Brazilian textbooks of Chemistry from XIX century to 1930. A revision of literature is made, as well as an analysis of some of these prime textbooks.

Assuntos Gerais

Educação