JBCS



8:54, sex mar 27

Edição Atual vol. 38, No. 2, 2015, p. 161-296



Artigo de Capa
Quim. Nova 2015, 38(2), 196-201

Síntese e caracterização de compósitos orgânico-inorgânicos macroporosos para o sensoriamento de H2O2

Juliana L. SantosI; Vinicius R. GonçalesII,#; Elaine P. CintraI; Susana I. Córdoba de TorresiII,*

Macroporous mediators can improve the performance of electrochemical sensors. However, in order to take full advantage of all porous structure, kinetics of the monitored reaction and hydrophobicity of the mediator are key points to be analyzed.

http://dx.doi.org/10.5935/0100-4042.20150011

Publicado online: fevereiro 11, 2015
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Artigos Quim. Nova 2015, 38(2), 161-165

 

Efeito dos tratamentos superficiais nas propriedades do bagaço da fibra de piaçava Attalea funifera Martius

Cleidiene S. MirandaI; Raigenis P. FiuzaII; Ricardo F. CarvalhoIII; Nadia M. JoséI,*


The aim of this study was to investigate the effect of surface treatment on the properties of waste piassava fiber. Washing the fibers was shown to be the best treatment, preserving the mechanical properties of the fibers while avoiding environmental damage.

http://dx.doi.org/10.5935/0100-4042.20140303

Publicado online: novembro 13, 2014
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Quim. Nova 2015, 38(2), 166-171

 

Synthesis and characterization of HDTMA-organoclays: insights into their structural properties

Pablo M. NaranjoI,*; José MolinaII; Edgardo Ling Sham I,III; Elsa M. Farfán TorresI,II


Schema of a tactoid (stacks of parallel clay platelets) of organoclay with a "house of cards" organization, where the surfactant is adsorbed via cationic exchange and Van der Waals forces. The interlayered exchanged cations and the counter ions are dispersed in the supernatant solution.

http://dx.doi.org/10.5935/0100-4042.20140302

Publicado online: novembro 13, 2014
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Quim. Nova 2015, 38(2), 172-177

 

Flavonoides de Piper glandulosissimum Yuncker (Piperaceae)

Fabiano Pereira SantosI; Harley da Silva AlvesII,*; Edeltrudes de Oliveira LimaIII; Maria Célia de Oliveira ChavesIII


This article reports the structural identification of six flavonoids and two derivatives isolated from Piper glandulosissimum, a shrub native to Northern Brazil. The antimicrobial activity of one flavanone was also determined.

http://dx.doi.org/10.5935/0100-4042.20140310

Publicado online: dezembro 12, 2014
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Quim. Nova 2015, 38(2), 178-184

 

Monitoramento de resíduos de agrotóxicos da classe dos organofosforados por CG-DFC em amostras de leite fluído e em pó

Lucia Helena Pinto Bastos*; Adherlene Vieira Gouvêa; Nina Daddário Ortiz; Maria Helena Wohlers Morelli Cardoso; Silvana do Couto Jacob ; Armi Wanderley da Nóbrega


The QuEChERS method and GC-FPD were used to evaluate the presence of OPS pesticide residues in liquid UHT and powdered milk. Twenty five percent of the samples were contaminated, indicating the need to improve quality control of this product.

http://dx.doi.org/10.5935/0100-4042.20140301

Publicado online: novembro 13, 2014
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Quim. Nova 2015, 38(2), 185-190

 

Caracterização e atividade catalítica de K2CO3/Al2O3 na transesterificação do óleo de girassol com aquecimento convencional e micro-ondas

Paola E. GamaI; Elizabeth R. LachterI,*; Rosane A. S. San GilI; Aline V. CoelhoI; Isadora A. SidiI; Rodrigo L. PoubelI; Arnaldo da Costa Faro Jr.I; Andrea L. F. de SouzaII


Aluminas impregnated with potassium carbonate were active for biodiesel production from sunflower seed oil, with high conversions by both conventional heating and microwave irradiation.

http://dx.doi.org/10.5935/0100-4042.20140300

Publicado online: novembro 13, 2014
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Quim. Nova 2015, 38(2), 191-195

 

Acidity of modified mordenites synthesized from rice husk silica and catalytic transformation of methylbutynol

Sittichai KulawongI; Sanchai PrayoonpokarachI; Frank RoessnerII; Jatuporn WittayakunI,*


Zeolite mordenite in sodium form (NaMOR) was synthesized using rice husk silica; modified with acid (A), base (B) and acid-base (AB); and acidity compared by NH3-TPD, 27Al NMR and catalytic transformation of methylbutynol.

http://dx.doi.org/10.5935/0100-4042.20150002

Publicado online: janeiro 16, 2015
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Quim. Nova 2015, 38(2), 202-208

 

Preparação e caracterização de membranas de celulose regenerada a partir da celulose extraída de resíduos agroindustriais para aplicação em processos de separação

Edmar Eustáquio de SouzaI; Rayane da Silva ValeI; Júlia Graciele VieiraI; Sabrina Dias RibeiroI; Guimes Rodrigues FilhoI; Fabiana Aparecida MarquesII; Rosana Maria Nascimento de AssunçãoIII,*,#; Carla da Silva MeirelesIV; Hernane da Silva BarudV,VI


The membranes produced from agroindustrial residues presented lower levels of Cu (II) ions compared with previous studies. The membranes exhibited no cytotoxic behavior and had good transport properties.

http://dx.doi.org/10.5935/0100-4042.20140299

Publicado online: novembro 13, 2014
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Quim. Nova 2015, 38(2), 209-213

 

Determinação de Cd e Pb em amostras de goma xantana por GF AAS

Alexander O. de SouzaI; Camila C. PereiraI; Bruna M. JadoI; Eliézer Q. OresteI; Mariana A. VieiraI; Anderson S. RibeiroI; Claire T. VendruscoloII ; Adriane M. NunesI,*


This paper presents a simple, safe and inexpensive method for determination of Cd and Pb in xanthan gum samples by GF AAS.

http://dx.doi.org/10.5935/0100-4042.20140298

Publicado online: novembro 13, 2014
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Quim. Nova 2015, 38(2), 214-220

 

Extração de poli(3-hidroxibutirato), produzido por Cupriavidus necator, com carbonato de propileno

Luci K. M. QuinesI; Jaciane L. IenczakII; Mélodi SchmidtI; Kellen ZanfonatoI; Maria I. RodriguesIII; Willibaldo SchmidellI; Gláucia M. F. AragãoI,*


Process of extracting poly(3-hydroxybutyrate) (P(3HB)), biopolymer stored as an intracellular energy and reserve source, from biomass of Cupriavidus necator DSM 545 treated by temperature increase, with propylene carbonate, a low toxicity solvent.

http://dx.doi.org/10.5935/0100-4042.20140297

Publicado online: novembro 13, 2014
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Quim. Nova 2015, 38(2), 221-226

 

Influência do conteúdo de xilanas na branqueabilidade, propriedades higroscópicas, fisico-mecânicas e óptica de polpas branqueadas de eucalipto

Valéria J. GomesI,*; Dalton Longue JrII; Jorge L. ColodetteII; Robisnéa A. RibeiroII; Heder BraunIII


The influence of xylan content of bleached pulp on Klemm capillarity is very high for pulps refined to a high level (P&W pulp). For tissue pulp, xylan content does not have a strong influence on this property nor on the P&W cited earlier, even though the values appear to be high.

http://dx.doi.org/10.5935/0100-4042.20140309

Publicado online: dezembro 12, 2014
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Quim. Nova 2015, 38(2), 227-232

 

Investigação da supressão de fluorescência de soro albumina bovina e humana por complexo de rutênio

Mariete B. Moreira; Douglas S. Franciscato; Kalil C. F. Toledo; João Raul B. de Souza; Helena S. Nakatani; Vagner R. de Souza*


Ruthenium complex quenched bovine and human serum albumin fluorescence. The binding sites for ruthenium complex were estimated in serum albumin. Dynamic and static quenching for serum albumin - ruthenium complex was discussed.

http://dx.doi.org/10.5935/0100-4042.20140315

Publicado online: dezembro 19, 2014
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Quim. Nova 2015, 38(2), 233-236

 

Método alternativo para a síntese e mecanismo de 2-(1,3-ditiano-2-ilideno)-acetonitrila

Marcelle S. Ferreira; José D. Figueroa-Villar*


Simple and effective method for two-step synthesis of 2-(1,3-dithian-2-ylidene)-acetonitrile (75% overall yield) and molecular modeling calculation of the mechanism by B3LYP and the 6-311++G(2df,2p) basis set.

http://dx.doi.org/10.5935/0100-4042.20140308

Publicado online: dezembro 12, 2014
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Quim. Nova 2015, 38(2), 237-242

 

Salacia crassifolia (Celastraceae): chemical constituents and antimicrobial activity

Vanessa G. RodriguesI,*; Lucienir P. DuarteI; Roqueline R. SilvaII; Grácia D. F. SilvaI; Maria O. Mercadante-SimõesIII; Jacqueline A. TakahashiI; Bibiane L. G. MatildesI; Thaisa H. S. FonsecaIV; Maria A. GomesIV; Sidney A. Vieira FilhoV


Ten pentacyclic triterpenes and a further four compounds were isolated from leaves of Salacia crassifolia. Their structures were established through IR, 1H and 13C NMR spectroscopic data. Some of the crude extracts and triterpenes presented in vitro antimicrobial property.

http://dx.doi.org/10.5935/0100-4042.20150001

Publicado online: janeiro 16, 2015
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Revisão Quim. Nova 2015, 38(2), 243-258

 

Distribuição, atividade biológica, síntese e métodos de purificação de podofilotoxina e seus derivados

Héctor Hugo S. MedradoI; Jorge M. DavidI,*; Juceni P. DavidII; Hugo N. BrandãoIII


Podophyllotoxin is a precursor of three semi-synthetic commercial anticancer agents. Today, efforts are being invested to obtain new sources of this compound. Several processes have been developed for its synthesis, extraction, and purification.

http://dx.doi.org/10.5935/0100-4042.20140294

Publicado online: outubro 24, 2014
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Quim. Nova 2015, 38(2), 259-267

 

Degradação microbiológica e enzimática de polímeros: uma revisão

Carolina Zanon CostaI,II; Marcos de C. C. de AlbuquerqueI,II; Maria Cristina BrumII; Aline Machado de CastroII,*


Biotechnological (enzymatic and/or microbial) degradation of polymers for the recovery of monomers and oligomers is promising and environmentally-friendly technology.

http://dx.doi.org/10.5935/0100-4042.20140293

Publicado online: outubro 24, 2014
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Nota Técnica Quim. Nova 2015, 38(2), 268-273

 

Monitoring of organophosphorous pesticide resdues in samples of banana, papaya, and bell pepper

Mariana F. Lemos; Mayara F. Lemos; Henrique P. Pacheco; Rodrigo Scherer*


The objective of this paper was to monitor organophosphorus residues in samples of banana, papaya, and bell pepper from ten different markets in Vitória and Vila Velha cities (Espírito Santo, Brazil) during a three-month period.

http://dx.doi.org/10.5935/0100-4042.20150005

Publicado online: janeiro 16, 2015
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Quim. Nova 2015, 38(2), 274-279

 

Novo sorvente de hidrofobicidade reduzida para extração em fase sólida: preparação e caracterização

Augusto S. Novais; Jarbas F. Ribeiro Filho; Eduardo M. F. Amaral e Anizio M. Faria*


A new sorbent for solid phase extraction based on a polysiloxane with octadecyl/hexadecyl interspersed with methyl groups immobilized on silica surface presented lower retention for hydrophobic molecules but similar selectivity to conventional C18 materials.

http://dx.doi.org/10.5935/0100-4042.20140312

Publicado online: dezembro 12, 2014
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Quim. Nova 2015, 38(2), 280-284

 

Kit colorimétrico para detecção de metanol em etanol combustível para o monitoramento da qualidade de combustíveis

Guilherme B. C. Martins; Mateus A. Montenegro; Paulo A. Z. Suarez*


Detection of methanol contamination in ethanol-based fuels by simple colorimetric qualitative or semi qualitative analysis adapted for ease of use in the field.

http://dx.doi.org/10.5935/0100-4042.20140305

Publicado online: novembro 13, 2014
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Educação Quim. Nova 2015, 38(2), 285-287

 

Enzymatic resolution of antidepressant drug precursors in an undergraduate laboratory

Luís M. R. SolanoI; Nuno M. T. LourençoII,*


This paper describes a multi-step chemo-enzymatic synthesis of antidepressant drug precursors.

http://dx.doi.org/10.5935/0100-4042.20140306

Publicado online: novembro 13, 2014
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Quim. Nova 2015, 38(2), 288-292

 

Estrategia de doble ciclo de supervisión clínica para la mejora de la calidad docente en la universidad. Punto de vista del profesorado novel

Diego Airado Rodríguez*,I; María Dolores Víctor OrtegaII


A strategy based on a double clinical supervision cycle has been implemented to enhance the quality of university teaching. Planning, action, analysis and reflection stages are well delimited.

http://dx.doi.org/10.5935/0100-4042.20140316

Publicado online: dezembro 19, 2014
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Quim. Nova 2015, 38(2), 293-296

 

Corrosão do aço-carbono: uma abordagem do cotidiano no ensino de química

Marcos V. F. Silva; Marinalda C. Pereira; Eduardo N. Codaro; Heloisa A. Acciari*


The visual colorimetric technique can be used to determine soluble product concentration during corrosion reactions.

http://dx.doi.org/10.5935/0100-4042.20140313

Publicado online: dezembro 12, 2014
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