27/10/2011
Saiu o JBCS número 11 - Volume 22
O JBCS acaba de lançar online seu décimo primeiro número de 2011 (vol. 22-11, correspondente a Novembro). A impressão e, portanto, distribuição da revista aos assinantes ocorrerá em breve.
Neste novo número, ilustrando nosso novo design de capa, temos o Article Automation of an Analysis System with Microvolume Porous Membrane Sampling, Capillary Electrophoresis Separation and Contactless Conductivity Detection for Near-Real-Time Monitoring of Traces of Low-Molecular-Weight Carboxylic Acids in Air dos autores Lúcia H. G. Coelho e Ivano G. R. Gutz. O texto editorial de autoria de Paulo A. Z. Suarez e Angelo C. Pinto trata do tema "Biodiesel de Algas: Promessa ou Futuro?". Ao todo, o JBCS vol. 22, No. 11 apresenta 215 páginas impressas, contendo 29 Artigos.
Assinem, e divulguem o JBCS. Façam um link de nossa página http://jbcs.sbq.org.br em sua instituição, laboratório ou empresa já que o acesso é aberto. Incentivem a leitura, pesquisa e citação ao JBCS.
Fonte: Elizabeth Magalhaes (JBCS)
Automation of an Analysis System with Microvolume Porous Membrane Sampling, Capillary Electrophoresis Separation and Contactless Conductivity Detection for Near-Real-Time Monitoring of Traces of Low-Molecular-Weight Carboxylic Acids in Air |
| Lúcia H. G. Coelho and Ivano G. R. Gutz |
|
Air pollutants that are water soluble and readily absorbed by the respiratory tract can be efficiently sampled with water filled microporous hollow tubular fibers acting as capillary membrane diffusion scrubber (CMDS). A short length of the CMDS filled with an absorbing solution and exposed to an air stream provides plenty of preconcentrated sample for capillary electrophoresis (CE), a technique with minute sample demand and high separation efficiency. Direct interfacing of CMDS with CE, combined with contactless conductivity detection (C4D) and computer management of fluid streams, allowed the implementation of fast repetitive analysis cycles for one or more trace compounds in air. |
The cover picture schematically depicts the CMDS-CE-C4D system being applied to the analysis of low-molecular weight carboxylic acids (formic acid and acetic acid) in outdoor air sampled at the University of São Paulo campus, surrounded by the metropolis of São Paulo. Details are discussed in the article: Automation of an Analysis System with Microvolume Porous Membrane Sampling, Capillary Electrophoresis Separation and Contactless Conductivity Detection for Near-Real-Time Monitoring of Traces of Low-Molecular-Weight Carboxylic Acids in Air by Lúcia H. G. Coelho and Ivano G. R. Gutz on page 2157. |
>> Editorial(214 KB)
Algae Biodiesel: a Promise or the Future?
Paulo A. Z. Suarez and Angelo C. Pinto |
| J. Braz. Chem. Soc. 2011, 22, 2023. |
Active Carbon Preparation from Treads of Tire Waste for Dye Removal in Waste Water |
Michael R. Nunes, Giordana M. Perez, Lara F. Loguercio, Eliete W. Alves, Neftali L. V. Carreño,
Jorge L. Martins and Irene T. S. Garcia |
| J. Braz. Chem. Soc. 2011, 22, 2027. |
|
| Graphical abstract shows the part of the tire which is used for recycling (treads), the scanning electron microscopy of the obtained carbons and, in first plane, the efficiency of these carbons in removing dye as function of time |
|
Web Release date: August 23, 2011. |
Microwave-Assisted Synthesis of Indole-2-Carboxylic Acid Esters in Ionic Liquid |
| Lijun Gu and Xiangguang Li |
| J. Braz. Chem. Soc. 2011, 22, 2036. |
|
| An improved procedure for the synthesis of indole-2-carboxylic acid esters in excellent yields has been achieved using ionic liquid under controlled microwave irradiation (100 W) at 50 °C |
|
Web Release date: August 25, 2011. |
Dispersing Carbon Nanotubes in Phenolic Resin using an Aqueous Solution |
| Edson C. Botelho, Elilton R. Edwards, Birgit Bittmann and Thomas Burkhart |
| J. Braz. Chem. Soc. 2011, 22, 2040. |
|
| The dispersion of carbon nanotubes in water with different surfactants, as well as its incorporation into phenolic resin, was investigated. Ultrasonication of liquid suspensions was used to prepare stable dispersions and to evaluate the best surfactant to be used. Light scattering and UV-Visible spectroscopy was performed. The image shows a SEM micrograph for fractured surface of 0.5 wt.% CNT/phenolic composite containing 0.5 wt% of PSS surfactant |
|
Web Release date: August 25, 2011. |
Multiresidue Methods for Determination of Pesticides using SPME and SPE Followed by GC-NPD System: a Comparative Study |
| Maria A. L. Milhome, Paula L. R. Sousa, Denis De Keukeleire and Ronaldo F. Nascimento |
| J. Braz. Chem. Soc. 2011, 22, 2048. |
|
| Extracted amount for the pesticides obtained with two different thicknesses of the polydimethylsiloxane fiber |
|
Web Release date: August 30, 2011. |
Square-Wave Cathodic Adsorptive Stripping Voltammetric Determination of 3-Hydroxyflavone, Morin and Hesperidin in Bulk Form and Biological Fluids in Absence and Presence of Cu(II) |
| Yassien M. Temerk, Mohamed S. Ibrahim and Mohammed Kotb |
| J. Braz. Chem. Soc. 2011, 22, 2056. |
|
| Validated, simple, fast and sensitive square-wave cathodic adsorptive stripping voltammetric procedure was described for the determination of 3-hydroxyflavone, morin and hesperidin in biological fluids. The LOD and LOQ calculated for the investigated flavonoids confirmed the sensitivity of the proposed procedure |
|
Web Release date: September 1, 2011. |
Microwave-Assisted Clean Synthesis of Amides via Aza-Wittig Reaction under Solvent-Free Condition |
| Murugan Sathishkumar, Sangaraiah Nagarajan, Poovan Shanmuga Velan, Murugan Dinesh and Alagusundaram Ponnuswamy |
| J. Braz. Chem. Soc. 2011, 22, 2065. |
|
| Solvent-free microwave-assisted amide synthesis via coupling of nascent phosphazenes with acyl chlorides or carboxylic anhydrides has been accomplished. It is an eco-friendly, rapid and simple approach eradicating the limitations associated with the prevailing time-consuming solution phase methodologies |
|
Web Release date: September 1, 2011. |
Comparative Study of the Catalytic Activity of the Complexes Cp*RuCl(PAr3)2
[Ar = -C6H5 and 4-CF3-C6H4] in the ATRP of Styrene |
Alejandro M. Villa-Hernández, Claudia P. Rosales-Velázquez, Enrique Saldívar-Guerra and
José R. Torres-Lubián |
| J. Braz. Chem. Soc. 2011, 22, 2070. |
|
| The SEC curves obtained during styrene polymerization mediated by ATRP catalysts 1 and 2 shows that the control of MW is better with catalyst 1 than 2. This is a consequence of the phosphine ligand properties |
|
Web Release date: September 1, 2011. |
Theoretical Substituent Electrophilicities |
| Marcos Caroli Rezende and Daniela Millán |
| J. Braz. Chem. Soc. 2011, 22, 2078. |
|
| Theoretical substituent electrophilicities σ w were derived from the global electrophilicity of substituted benzoic acids, with applications to a variety of chemical processes. The good correlation between the theoretical σ w and the empirical Hammett’s σ for uncharged substituents is discussed and explained |
|
Web Release date: September 1, 2011. |
Phenylpropanoid Substituted Flavan-3-ols from Trichilia catigua and their In Vitro Antioxidative Activity |
Flávia O. Resende, Edson Rodrigues-Filho, Heinrich Luftmann, Frank Petereit and
João C. Palazzo de Mello |
| J. Braz. Chem. Soc. 2011, 22, 2087. |
|
The phenylpropanoid substituted flavan-3-ol apocynin E was isolated along with eight known compounds from the stem bark of Trichilia catigua. All of them exhibited higher radical scavenging activity and reducing power than ascorbic acid and Trolox |
|
Web Release date: September 6, 2011. |
Metal Speciation in Surface Sediments of the Uberabinha River in Uberlândia, MG State, Brazil |
| Luciano A. da Silva, Luciana M. Coelho, Vania Rosolen and Nívia M. Melo Coelho |
| J. Braz. Chem. Soc. 2011, 22, 2094. |
|
| The figure shows distribution of Cu in fractions obtained through sequential extraction. The sequential extractions allowed the portion of metals associated with the 13 non-residual (FR1: acid extractable, FR2: reducible, FR3: oxidizable) and residual 14 fractions (R) of the sediment to be determined |
|
Web Release date: September 6, 2011. |
Synthesis and Mechanism of Formation of Oxadeazaflavines by Microwave Thermal Cyclization of ortho-Halobenzylidene Barbiturates |
| J. Daniel Figueroa-Villar and Sandra C. G. de Oliveira |
| J. Braz. Chem. Soc. 2011, 22, 2101. |
|
| Oxadeazaflavines are prepared in 5 min by solid state microwave cyclization of ortho-halobenzylidene barbiturates with yields above 90%. Molecular modeling simulations indicate as mechanism an intramolecular hetero Diels-Alder cyclization followed by loss of HX leading to rearomatization |
|
Web Release date: September 6, 2011. |
Local Electrochemical Investigation of Single Grains of Polycrystalline Cu-16%Zn-8%Al Alloy |
| José T. C. Barragan, Matildes Blanco, Nilso Barelli, Rodrigo Della Noce, Cecílio S. Fugivara, Javier Fernández and Assis V. Benedetti |
| J. Braz. Chem. Soc. 2011, 22, 2108. |
|
| Micrograph of single grains of polycrystalline Cu-16%Zn-8%Al alloy obtained by petrographic microscopy |
|
Web Release date: September 8, 2011. |
Action of Successive Heat Treatments in Bovine Milk Fatty Acids |
| Edvaldo N. Costa, Ellen C. Q. Lacerda, Suian M. S. Santos, Carilan M. S. Santos, Marcelo Franco, Robério R. Silva and Julliana I. Simionato |
| J. Braz. Chem. Soc. 2011, 22, 2115. |
|
| In octadienoic acid profiles to raw, pasteurized and sterilized milk samples occurs significant difference between raw and UHT milks for CLAc9t12 and 18:2c9c12 and no difference between raw and UHT milks for CLAt10c12. This fact evidences the successive action of heat treatments on milk lipid profile |
|
Web Release date: September 13, 2011. |
Comprehensive Two-Dimensional Gas Chromatography with Time of Flight Mass Spectrometry Applied to Analysis of Fischer-Tropsch Synthesis Products Obtained with and without Carbon Dioxide Addition to Feed Gas |
| Raphael S. F. Silva, Juliana B. Tamanqueira, Julio César M. Dias, Fábio M. Passarelli, Antonio Marcos F. Bidart, Francisco R. Aquino Neto and Débora A. Azevedo |
| J. Braz. Chem. Soc. 2011, 22, 2121. |
|
| Selected region of a chromatogram obtained by comprehensive two-dimensional gas chromatography of synthetic fuels produced by Fischer-Tropsch synthesis. High level of resolution for n-alkanes, branched alkenes, alkenes and n-alcohols analysis was promoted by this technique |
|
Web Release date: September 13, 2011. |
Distribution of Indoor Air Pollutants in Downtown Rio de Janeiro, Brazil |
Celeste Y. S. Siqueira, Adriana Gioda, Fabiana P. Carneiro, Maria da Conceição K. V. Ramos and
Francisco R. Aquino Neto |
| J. Braz. Chem. Soc. 2011, 22, 2127. |
|
| Total volatile organic compound (TVOC) concentrations ranged from 101 to 12823 μg m-3, with an average of 1594 μg m-3 that exceeds the suggested limit (300 μg m-3). Indoor/outdoor ratios for most of the parameters were higher than unit, indicating indoor sources of pollution. Overall, the environments did not present good air quality for the occupants due to chemical pollutants |
|
Web Release date: September 20, 2011. |
Characterization of Dissolved Organic Matter in the Piauí River Estuary, Northeast Brazil |
Adnivia Santos Costa, Elisangela de Andrade Passos, Carlos A. B. Garcia and
José do Patrocinio H. Alves |
| J. Braz. Chem. Soc. 2011, 22, 2139. |
|
| Fluorescence spectroscopy was used to accompany the evolution of DOM during the mixing of fluvial and marine waters in the Piauí River estuary, which is a tropical estuary situated in the State of Sergipe, Northeast Brazil |
|
Web Release date: September 20, 2011. |
Enzymatic Synthesis Optimization of Isoamyl Butyrate |
| Andréia Anschau, Vitor C. Aragão, Barbara D. A. Porciuncula, Susana J. Kalil, Carlos A. V. Burkert and Janaína F. M. Burkert |
| J. Braz. Chem. Soc. 2011, 22, 2148. |
|
| Lipozyme TL IM was used to catalyse the esterification of isoamyl alcohol and butyric acid using hexane as solvent. The reaction was carried out in shaking incubator and the percent of isoamyl butyrate and its concentration was determined by titration |
|
Web Release date: September 23, 2011. |
Automation of an Analysis System with Microvolume Porous Membrane Sampling, Capillary Electrophoresis Separation and Contactless Conductivity Detection for Near-Real-Time Monitoring of Traces of Low-Molecular-Weight Carboxylic Acids in Air |
| Lúcia H. G. Coelho and Ivano G. R. Gutz |
| J. Braz. Chem. Soc. 2011, 22, 2157. cover article |
|
Automated CMDS-CE-C4D system for the near-real-time monitoring of low-molecular-weight carboxylic acids in air |
|
Web Release date: September 23, 2011. |
Dual Bifunctional Catalysis and the a-Effect in the Reaction of Hydroxylamine with Phenylacetate |
| Deise J. Mazera, Josefredo R. Pliego Jr., Gizelle I. Almerindo and José C. Gesser |
| J. Braz. Chem. Soc. 2011, 22, 2165. |
|
| Dual bifunctional catalysis plays an important role in the α-effect for the reaction of hydroxylamine with phenylacetate |
|
Web Release date: September 27, 2011. |
Determination of Sulfamethoxazole in Pharmaceutical Formulations by Flow Injection System/HPLC with Potentiometric Detection using Polypyrrole Electrode |
| Sabriye P. Ozkorucuklu, Yucel Sahin and Guleren Alsancak |
| J. Braz. Chem. Soc. 2011, 22, 2171. |
|
| The use of polypyrrole (PPy) as a potentiometric detector in high performance liquid chromatography (HPLC) for determination of sulfamethoxazole is reported in this work. The PPy electrode was successfully applied as a potentiometric detector for fast and accurate determination of sulfamethoxazole in standards and pharmaceutical samples |
|
Web Release date: September 29, 2011. |
A Monte Carlo Revisiting of N-Methylformamide and Acetone |
| Glauco G. Almeida and João M. M. Cordeiro |
| J. Braz. Chem. Soc. 2011, 22, 2178. |
|
| Is there anything else to be learned about the structure of liquids N-methylformamide and acetone? Yes, there is! |
|
Web Release date: October 4, 2011. |
DBU as a Catalyst for the Synthesis of Amides via Aminolysis of Methyl Esters |
| Evanoel Crizanto de Lima, Carolina C. de Souza, Renato de O. Soares, Boniek Gontijo Vaz, Marcos N. Eberlin, Ayres G. Dias and Paulo R. R. Costa |
| J. Braz. Chem. Soc. 2011, 22, 2186. |
|
| Use of DBU as an efficient catalyst for the chemoselective aminolysis of methyl esters leading to amides, as tested by the reactions employing esters and amines |
|
Web Release date: October 4, 2011. |
The Effect of Different Chemical Treatments on the Structure and Stability of Aqueous Dispersion of Iron- and Iron Oxide-Filled Multi-Walled Carbon Nanotubes |
| Rodrigo A. Moraes, Carolina F. Matos, Eryza G. Castro, Wido H. Schreiner, Marcela M. Oliveira and Aldo J. G. Zarbin |
| J. Braz. Chem. Soc. 2011, 22, 2191. |
|
| The homogeneity, surface chemistry, structure and dispersibility in water of iron- and iron oxide-filled multi-walled carbon nanotubes are affected by different chemical treatments |
|
Web Release date: October 6, 2011. |
Alum-Catalyzed One-Pot Synthesis of Dihydropyrano[3,2-b] chromenediones |
| Wei Lin Li, Li Qiang Wu and Fu Lin Yan |
| J. Braz. Chem. Soc. 2011, 22, 2202. |
|
| A simple, green and efficient solventless procedure for the synthesis of eleven dihydropyrano[3,2-b]chromenediones from the threecomponent condensation reaction of kojic acid, aromatic aldehydes, and dimedone employing alum as reusable catalyst is described |
|
Web Release date: October 6, 2011. |
A Second-Order Standard Addition Method based on the Data Treatment by Calculation of Variation Matrix of Kinetic Systems Analyzed by MCR-ALS |
| Abdolhossein Naseri, Morteza Bahram and Mehdi Mabhooti |
| J. Braz. Chem. Soc. 2011, 22, 2206. |
|
| A new second-order standard addition method is proposed to resolve the kinetic-spectrophotometric data of multicomponent mixtures and determination of analyte(s) in the presence of unknown matrix. The method uses variation matrices data by shifting to another target, namely the reaction space |
|
Web Release date: October 6, 2011. |
Alkaloid and other Chemical Constituents from Psychotria stachyoides Benth. |
Antonia T. A. Pimenta, Daniel E. A. Uchôa, Raimundo Braz-Filho, Edilberto R. Silveira and
Mary Anne S. Lima |
| J. Braz. Chem. Soc. 2011, 22, 2216. |
|
| A complete structural characterization is presented for the new alkaloid N-demethylcorreantoside, isolated from the leaves of Psychotria stachyoides |
|
Web Release date: August 25, 2011. |
Microwave Irradiation or Low Temperature Improved Synthesis of Antiparasitic Morita-Baylis-Hillman Adducts |
| Claudio G. L. Junior, Fábio P. L. Silva, Ramon G. de Oliveira, Fernanda L. Subrinho, Natália G. de Andrade and Mário L. A. A. Vasconcellos |
| J. Braz. Chem. Soc. 2011, 22, 2220. |
|
| We report the synthesis of 24 Morita-Baylis-Hillman adducts using microwave irradiation at 80 °C or conventional protocol at 0 °C to promote the reactions in high yields (81-99%) |
|
Web Release date: August 25, 2011. |
Effect of the Subsampling Ratio in the Application of Subagging for Multivariate Calibration with the Successive Projections Algorithm |
| Arlindo R. Galvão Filho, Roberto K. H. Galvão and Mário César U. Araújo |
| J. Braz. Chem. Soc. 2011, 22, 2225. |
|
| Multi-criterion analysis of the effects of subsampling ratio q on the subagging approach for multiple linear regression with variable selection by the successive projections algorithm |
|
Web Release date: September 15, 2011. |
A New Megastigmane Diglycoside from Litsea glutinosa (Lour.) C. B. Rob. |
| Yun-Song Wang, Zhen Liao, Yan Li, Rong Huang, Hong-Bing Zhang and Jing-Hua Yang |
| J. Braz. Chem. Soc. 2011, 22, 2234. |
|
Phytochemical study on the leaves and twigs of Litsea glutinosa (Lour.) C. B. Rob. afforded the new megastigmane diglycoside (6S, 7E, 9R)-6, 9-dihydroxy-4, 7-megastigmadien-3-one-9-O-[α-L-arabinofuranosyl-(1→6)]-β-d-glucopyranoside (1), along with four known glycosides (2-4) |
|
Web Release date: September 29, 2011. |
|
