Editorial Há futuro para as revistas das sociedades científicas? Torresi, Susana I. Córdoba de Pardini, Vera L. Ferreira, Vitor F. Andrade, Jailson B. de |
Preliminary study of insect attraction by a mixture of semiochemicals containing 1,2,4-Trimethoxybenzene in domestic citric-culture Alves, Ana Paula L. C. Júnior, José Augusto B. de Slana, Glaucia B. A. Cardoso, Jari N. Lopes, Rosangela S. C. Lopes, Claudio C. Resumo em Inglês: In this work we describe a new efficient strategy for the preparation of 1,2,4-trimethoxybenzene (3) in 56% overall yield. The compound 3 was used in a preliminary study of insect attraction by a mixture of semiochemicals called TIV, composed of indol (1), vanillin (2) and 1,2,4-trimethoxybenzene (3), in eight Mc Phail style traps installed at a domestic orchard of citric-culture, containing 120 trees not infected by plagues in Bom Jesus Farm, located next to a patch of the Atlantic Forest, at Silva Jardim, Rio de Janeiro, Brazil. |
Artigo Efeitos da incorporação de peneiras moleculares 3A, 4A, 5A e 13X em membranas compósitas de quitosana/poli(vinil álcool) Vicentini, Denice Schulz Lima, João Cardoso de Laranjeira, Mauro Cesar Marghetti Resumo em Inglês: The composite membranes prepared via incorporation of 12.5% of molecular sieves 3A, 4A, 5A and 13X into chitosan/poly(vinyl alcohol) (1:1). The composite membranes were immersed in the cross-linker sulfuric acid in order to acquire high proton conductivity for applications in electrolytes in PEMCF and DMF. The influence of the molecular sieves on the structural, optical, thermal, mechanical, morphologic and protonic conductivity properties and water/methanol swelling degree of membranes were investigated. |
Volatile compounds from Rosmarinus officinalis L. and Baccharis dracunculifolia DC. Growing in southeast coast of Brazil Boix, Yilan Fung Victório, Cristiane Pimentel Lage, Celso Luiz Salgueiro Kuster, Ricardo Machado Resumo em Inglês: Chemical composition of leaf volatiles of Rosmarinus officinalis and Baccharis dracunculifolia cultured in Southeast of Brazil has been characterized by GC/MS after simultaneous distillation-extraction. The main components in volatiles of these species showed in common α-pinene, myrcene, 1,8 cineole and camphor. Camphor was the major component among volatiles of B. dracunculifolia and R. officinalis with concentrations exceeding 25%. B. dracunculifolia volatiles possessed more sesquiterpenes (21.4%) than R. officinalis (16.7%), such as caryophyllene (1.9%) and α-humulene (0.4%). Lower concentrations of nerolidol and spathulenol were achieved in volatiles of B. dracunculifolia. Considering both species, there was a predominance of monoterpenes. |
Artigo Influência de diferentes sistemas de solvente água-etanol sobre as propriedades físico-químicas e espectroscópicas dos compostos macrocíclicos feofitina e clorofila α Moreira, Leonardo M. Rodrigues, Máira R. Oliveira, Hueder P. M. de Lima, Adriana Soares, Rafael R. S. Batistela, Vagner R. Gerola, Adriana P. Hioka, Noboru Severino, Divinomar Baptista, Mauricio S. Machado, Antônio Eduardo da Hora Resumo em Inglês: This work focus on the influence of solvent on the photophysical properties of chlorophyll α and pheophytin. Both compounds are related to the photosynthesis process and are considered prototypes of photosensitizers in Photodynamic Therapy. Fluorescence measurements were developed using water/ethanol mixtures at different compositions, since both solvents could be employed in biological applications. The spectroscopic properties of these compounds undergo profound changes depending on water content in the ethanol due to auto-aggregation processes. The major hydrophobicity and the lower dielectric constant of ethanol when compared with water precluded significantly the auto-aggregation process of these compounds. |
Artigo Produção de micropartículas de alginato contendo Flavobacterium columnare inativada pelo método de emulsão para vacinação de peixes por via oral Sacchetin, Priscila Soares Costa Moraes, Ângela Maria Leal, Carlos Augusto Gomes Figueiredo, Henrique César Pereira Resumo em Inglês: Alginate microparticles were prepared by an emulsion method aiming oral controlled release of antigens to fish. The effects of emulsification temperature and impeller type on particle morphology, average diameter, and size distribution were evaluated. Microparticles contaning formalin-killed Flavobacterium columnare cells (a model antigen) were prepared and characterized regarding bacterial release and particle stability when exposed to Nile tilapia (Oreochromis niloticus) typical gastrointestinal conditions. This methodology allowed the production of microparticles containing up to 14.3 g/L of bacterin, stable at a pH range from 2.0 to 9.0 for 12 h and smaller than 35 μm. |
Preparation and characterization oF Ru-Sn/Al2O3 catalysts for the hydrogenation of fatty acid methyl esters Mazzieri, Vanina A. Sad, Mario R. Vera, Carlos R. Pieck, Carlos L. Grau, Ricardo Resumo em Inglês: Ru-Sn/Al2O3 catalysts with different Sn loadings were prepared by the coimpregnation method. Several characterization techniques such as TPR, pyridine TPD and catalytic tests for dehydrogenation and hydrogenolysis were used to evaluate and compare such catalysts. TPR results indicate that Sn is deposited both onto the support and as species strongly interacting with Ru. Such non selective deposition modifies the acid and metallic functions of the catalysts. Both total acidity and acid strength distribution are affected: total acidity decreases and new sites of lower acid strength are created. Both dehydrogenating and hydrogenolytic activities are strongly diminished by the addition of Sn. Results of catalytic tests for methyl oleate hydrogenation indicate that methyl stearate is the main product, with only minute amounts of oleyl alcohol produced, and that the addition of Sn diminishes the hydrogenation activity. |
Artigo Efeito da aplicação de nitrato na redução biogênica de sulfeto sob diferentes concentrações iniciais de bactérias redutoras de nitrato e sulfato Sousa, Kally Alves de Cammarota, Magali Christe Sérvulo, Eliana Flávia Camporese Resumo em Inglês: The effect of sodium nitrate application in the reduction of biogenic sulphide was evaluated through a 2k complete factorial design, using as variable response the production of sulfide at intervals of incubation of 7, 14 and 28 days. The most effective condition for reducing the sulphide production (final concentrations from 0.4 to 1.6 mg S2- L-1) was obtained with an initial population of sulphate-reducing bacteria and nitrate-reducing bacteria of 10(4) MPN mL-1 and 427.5 mg L-1 nitrate. The results also suggested that the applications of nitrate to control the process of souring should follow a continuous scheme. |
Plasmid DNA damage induced by singlet molecular oxygen released from the naphthalene endoperoxide DHPNO2 and photoactivated methylene blue Berra, Carolina Maria Menck, Carlos Frederico Martins Martinez, Glaucia Regina Oliveira, Carla Santos de Baptista, Maurício da Silva Di Mascio, Paolo Resumo em Inglês: To investigate oxidative lesions and strand breaks induction by singlet molecular oxygen (¹O2), supercoiled-DNA plasmid was treated with thermo-dissociated DHPNO2 and photoactivated-methylene blue. DNA lesions were detected by Fpg that cleaves DNA at certain oxidized bases, and T4-endoV, which cleaves DNA at cyclobutane pyrimidine dimers and apurinic/apyrimidinic (AP) sites. These cleavages form open relaxed-DNA structures, which are discriminated from supercoiled-DNA. DHPNO2 or photoactivated-MB treatments result in similar plasmid damage profile: low number of single-strand breaks or AP-sites and high frequency of Fpg-sensitive sites; confirming that base oxidation is the main product for both reactions and that ¹O2 might be the most likely intermediate that reacts with DNA. |
Artigo Alcaloides indólicos de cascas de Aspidosperma vargasii e A. desmanthum Henrique, Marycleuma Campos Nunomura, Sergio Massayoshi Pohlit, Adrian Martin Resumo em Inglês: Fractionation of extracts resulted in isolation and identification of indole alkaloids ellipticine and N-methyltetrahydroellipticine from A. vargasii and aspidocarpine from A. desmanthum. Identification of these compounds was achieved based on IR, MS, ¹H, 13C and 2-D NMR data and comparison to data in the literature. |
Artigo Otimização de metodologia analítica para o doseamento de flavonoides de Bauhinia cheilantha (Bongard) Steudel Peixoto Sobrinho, Tadeu José da Silva Gomes, Tiago de Lima Barros Cardoso, Késsio Carlos de Macedo Amorim, Elba Lúcia Cavalcanti de Albuquerque, Ulysses Paulino de Resumo em Inglês: The present study examined the optimization of stabilization and extraction processes of the flavonoids of Bauhinia cheilantha (Bongard) Steudel. Four drying temperatures (room temperature, 40, 60 and 80 ºC) and seven extraction systems (distilled water, 100% methanol, 80% methanol, 100% ethanol, 80% ethanol, 80% acetone and 60% acetone) were examined. The results demonstrated a reduction in flavonoid levels with increasing drying temperatures; and 80% acetone, 80% ethanol, and methanol p.a extraction systems were found to be most efficient and its weren't differents statisticaly (p<0.05). |
Antifungal iridoids, triterpenes and phenol compounds from Alibertia myrciifolia Sprunge Ex. Schum Luciano, João Henrique S. Lima, Mary Anne S. Silveira, Edilberto Rocha Vasconcelos, Ilka Maria Fernandes, Georgia Sampaio Souza, Elnatan Bezerra de Resumo em Inglês: The new iridoid glucoside 10-O-vanilloyl-geniposidic acid has been isolated from the aerial parts of Alibertia myrciifolia along with hydroxyhopanone, 3α,22-dihydroxyhopane, ursolic acid, luteolin-3´,4´-dimethyl ether, caffeic acid and geniposidic acid. The structures of the isolated compounds were determined by means of mass spectrometry and nuclear magnetic resonance spectral analyses. The antifungal activities of the iridoids 10-O-vanilloyl-geniposidic acid and geniposidic acid were evaluated against the phytopathogenic fungi strains Colletotrichum gloeosporioides, Fusarium solani and Aspergillus niger. |
Artigo Nanoemulsões óleo de laranja/água preparadas em homogeneizador de alta pressão Kourniatis, Loretta R. Spinelli, Luciana S. Mansur, Claudia R. E. González, Gaspar Resumo em Inglês: The objective of this work was to use the high-pressure homogenizer (HPH) to prepare stable oil/water nanoemulsions presenting narrow particle size distribution. The dispersions were prepared using nonionic surfactants based on ethoxylated ether. The size and distribution of the droplets formed, along with their stability, were determined in a Zetasizer Nano ZS particle size analyzer. The stability and the droplet size distribution in these systems do not present the significant differences with the increase of the processing pressure in the HPH). The processing time can promote the biggest dispersion in the size of particles, thus reducing its stability. |
Artigo Emprego de sílica gel organicamente modificada e impressa ionicamente para pré-concentração seletiva on-line de íons cobre Ávila, Thiago Carvalho de Segatelli, Mariana Gava Beijo, Luiz Alberto Tarley, César Ricardo Teixeira Resumo em Inglês: The present work purposes the preparation of a silica gel sorbent organically modified with 2-aminoethyl-3-aminobutylmethyldimethoxysilane (AAMDMS) and imprinted with Cu2+ ions by means surface imprinting technique and its use for selective on-line sorbent preconcentration of Cu2+ ions with further UV-VIS spectrophotometric determination by flow injection analysis. The Cu2+-imprinted silica gel, when compared with non imprinted silica gel and silica gel, showed from the binary mixture of Cu2+/Ni2+ relative selectivity coefficient (k') of 6.84 and 5.43 and 6.64 and 19.83 for the mixture Cu2+/Pb2+, thus demonstrating higher selectivity of Cu2+-imprinted silica gel towards Cu2+ ions. Under optimized condition, the on-line preconcentration method provided detection limit of 3.4 μg L-1 and linear range ranging from 30.0 up to 300.0 μg L-1 (r = 0.995). The accuracy of method was successfully assessed by analyzing different kind of spiked water samples with recovery values ranging from 92.2 up to 103.0%. |
Modification of a Brazilian smectite clay with different quaternary ammonium salts Delbem, Maria Flávia Valera, Ticiane S. Valenzuela-Diaz, Francisco R. Demarquette, Nicole R. Resumo em Inglês: In this work, a smectite clay from the State of Paraiba, Brazil, was treated with six different types of ammonium salts, which is an usual method to enhance the affinity between the clay and polymer for the preparation of nanocomposites. The clays, before and after modification, were characterized by X ray diffraction. The conformation of the salts within the platelets of the clay depended on the number of long alkyl chains of the salt. The thermal stability of the clays was also studied. The ammonium salts thermal decomposition was explained in light of their position within the organoclays. |
Artigo Determinação simultânea de precursores de serotonina - triptofano e 5-hidroxitriptofano - em café Martins, Ana Carolina C. L. Silva, Tarliane M. Gloria, M. Beatriz A. Resumo em Inglês: Epidemiological studies attributed positive effects in the central nervous system (CNS) to coffee. Among possible active constituents, serotonin, a neurotransmitter in the CNS, is present; but dietary sources do not cross the blood-brain barrier. Tryptophan and 5-hidroxytryptophan (5-HTP) are serotonin precursors and can affect brain concentrations. An ion-pair-HPLC, post-column derivatization with o-phthalaldehyde and fluorimetric detection before and after hydrolysis with NaOH and extraction with methanol:water was developed for the simultaneous determination of these compounds. It was selective, sensitive (LOD = 0.3 and 0.2 μg/mL), precise (91.3 and 94.2% recovery for tryptophan and 5-HTP, respectively), and linear from 0.3 to 40 μg/mL for both compounds. It was applied to green and roasted arabica and robusta coffees. |
Aromatic compounds from three Brazilian Lauraceae species Batista, Andrea Nastri de Luca Batista Junior, João Marcos López, Silvia Noelí Furlan, Maysa Cavalheiro, Alberto José Silva, Dulce Helena Siqueira Bolzani, Vanderlan da Silva Nunomura, Sergio Massayoshi Yoshida, Massayoshi Resumo em Inglês: Phytochemical investigations on three Brazilian Lauraceae species from the Cerrado region of São Paulo State, Ocotea corymbosa (Meins) Mez., O. elegans Mez. and Persea pyrifolia Nees & Mart. ex Nees resulted in the isolation of flavonoids, an ester of the 4-O-E-caffeoylquinic acid, an aromatic sesquiterpene besides furofuran lignans. This is the first chemical study on the leaves of Ocotea elegans and O. corymbosa as well as the first report of non-volatile compounds from Persea pyrifolia. |
Artigo Utilização de resíduos agroindustriais para a produção de proteases pelo termofílico Bacillus sp em fermentação submersa: otimização do meio de cultura usando a técnica de planejamento experimental Ladeira, Silvania Alves Andrade, Marcela Vicente Vieira Delatorre, Andréia Boechat Perez, Victor Haber Martins, Meire Lélis Leal Resumo em Inglês: Thermophilic Bacillus sp. SMIA-2, produced protease when grown on apple pectic, whey protein and corn step liquor medium, whose concentration was varied from 3 to 10 gL-1, according to the central composite design 2³. The experiments were conducted in shaker, at 50 °C, 150 rpm and initial pH 6.5. The results revealed that the culture medium affected both, cell growth and enzyme production. After graphical and numerical optimization procedure, the enzyme production reached its maximum value at 30 h fermentation, reaching, approximately, 70 U protein mg-1, suggesting that this process was partially associated to the growth. |
Artigo Otimização e validação de métodos analíticos para determinação de BTEX em água utilizando extração por headspace e microextração em fase sólida Heleno, Fernanda F. Lima, Aniel C. Afonso, Robson J. C. F. Coutrim, Mauricio X. Resumo em Inglês: Three analytical methods for the determination of BTEX in water were optimized and validated. With the best method the analytes were extracted of 10 mL of sample with 2.50 g of NaCl in headspace vial of 20 mL by HS and SPME to 40 ºC for 30 min for adsorption and to 250 ºC for 4 min for desorption and were analyzed by GC-MS. The recovery was between 97.9% and 104.3%, and the limit of detection was 2.4 ng L-1 for o-xylene. This method was using to analyze BTEX in water supply and surface water in Ouro Preto city. No sample had concentrations of BTEX above the legislation. |
Air pollution and emergency admissions for cardiorespiratory diseases in Lisbon (Portugal) Alves, Célia A. Scotto, Manuel G. Freitas, Maria do Carmo Resumo em Inglês: Daily records of hospital admissions due to cardiorespiratory diseases and levels of PM10, SO2, CO, NO, NO2, and O3 were collected from 1999-2004 to evaluate the relationship between air pollution and morbidity in Lisbon. Generalised additive Poisson regression models were adopted, controlling for temperature, humidity, and both short and long-term seasonality. Significant positive associations, lagged by 1 or 2 days, were found between markers of traffic-related pollution (CO and NO2) and cardiocirculatory diseases in all age groups. Increased childhood emergency admissions for respiratory illness were significantly correlated with the 1-day lagged SO2 levels coming from industrial activities. |
Artigo Modificação enzimática da farinha de arroz visando a produção de amido resistente Severo, Márcio Garcia Moraes, Kelly de Ruiz, Walter Augusto Resumo em Inglês: The aim of this work was to study the enzymatic modification on rice flour using lipase pancreatic and amyloglucosidase to obtain resistant starch. For this, Response Surface Methodology (RSM) was used to determine the best operating conditions for each enzyme. For lypase pancreatic, the highest value for resistant starch (45%) was achieved within 2 h reaction at pH 7 using an enzyme/substrate ratio of 4% (w/w) and Dp= 100/200 tyler. For amyloglucosidase, optima conditions corresponded to an enzyme/substrate ratio of 0,006 mL/g and Dp= 100/200 tyler at 45 ºC, yielding 57% of resistant starch in 2 h reaction. These results show the potential of using both enzymes to modified rice flour, increasing the resistant starch in about 5.7 folds in relation to the flour without treatment (resistant starch=10.6%). |
Artigo Análise screening de vinhos empregando um analisador fluxo-batelada, espectroscopia UV-VIS e quimiometria Nascimento, Jaqueline Azevedo Dionísio, Amália Geíza Gama Nascimento, Elaine Cristina Lima do Freitas, Sueny Kêlia Barbosa Araújo, Mário César Ugulino de Resumo em Inglês: A simple, robust, versatile, high analytical frequency method was proposed to check if a sample of wine is within the range of standards set by the manufacturer, using the UV-VIS spectroscopy, multivariate analysis and a flow-batch analyzer. Two hundred and fifty-two samples of wines were analyzed. The results from the application of Hierachical Cluster Analysis (HCA) to the matrix of the data involving all samples show the formation of fifteen types of wine. A Soft Independent Modelling of Class Analogy (SIMCA) model was constructed and used to classify the samples of the overall forecast. As a result, it is observed that the prediction was performed with a success rate of 99.2% for a confidence level of 95%. This shows that the proposed methodology can be used as an effective tool for classifying of samples of wines. |
Artigo Adsorção do corante reativo laranja 16 de soluções aquosas por zeólita sintética Carvalho, Terezinha Elizabeth Mendes de Fungaro, Denise Alves Izidoro, Juliana de Carvalho Resumo em Inglês: Coal fly ash, a waste generated in a coal-fired electric power plant, was used to synthesize zeolite by hydrothermal treatment with NaOH solution. This zeolite was used as adsorbent to investigate the adsorption kinetics and isotherm parameters of the reactive orange 16 (RO16) dye from aqueous solutions at different concentrations (1.3-15.4 mg L-1). Three kinetic models, the pseudo-first-order, second-order, and intraparticle diffusion were used to predict the adsorption rate constants. The kinetics of adsorption of the RO16 dye followed pseudo-second-order kinetics. The adsorption isotherm data were closely fitted to the Langmuir equation. Keywords: coal fly ash; zeolite; reactive dye adsorption. |
Artigo Interferência da lignina na quantificação de radicais livres no processo de compostagem Fialho, Lucimar Lopes Silva, Wilson Tadeu Lopes da Milori, Débora M. B. P. Simões, Marcelo Luiz Martin-Neto, Ladislau Saab, Sérgio da Costa Resumo em Inglês: In this work was studied composts and their humic acids (HA) to evaluate the use of EPR in the monitoring of the humification. It was observed increase in the concentration of organic free radical (OFR) in all the composts, but in L1 the increase was more significant than L2 and L3. Research more detailed of L1 showed that the lignin is main source of OFR. Then determination of these radicals in material in nature that contains high amount of lignin isn't a good indicator to monitor the humification process in the composting and yes the fraction HA of the composts. |
Método extendido de Hildebrand en la predicción de la solubilidad del ketoprofeno en mezclas cosolventes etanol + agua Gantiva, Mauricio Martínez, Fleming Resumo em Inglês: Extended Hildebrand Solubility Approach (EHSA) developed by Martin et al. was applied to evaluate the solubility of ketoprofen (KTP) in ethanol + water cosolvent mixtures at 298.15 K. Calculated values of molar volume and solubility parameter for KTP were used. A good predictive capacity of EHSA was found by using a regular polynomial model in order five to correlate the W interaction parameter and the solubility parameters of cosolvent mixtures (δmix). Nevertheless, the deviations obtained in the estimated solubilities with respect to the experimental solubilities were on the same order like those obtained directly by means of an empiric regression of the logarithmic experimental solubilities as a function of δmix values. |
Losartan potassium dissolution test for drug release evaluation in pharmaceutical capsules using HPLC and UV spectrophotometry Bonfilio, Rudy Mendonça, Taciane Ferreira Pereira, Gislaine Ribeiro Araújo, Magali Benjamim de Tarley, César Ricardo Teixeira Resumo em Inglês: This work describes the development and validation of a dissolution test for 50 mg losartan potassium capsules using HPLC and UV spectrophotometry. A 2(4) full factorial design was carried out to optimize dissolution conditions and potassium phosphate buffer, pH 6.8 as dissolution medium, basket as apparatus at the stirring speed of 50 rpm and time of 30 min were considered adequate. Both dissolution procedure and analytical methods were validated and a statistical analysis showed that there are no significant differences between HPLC and spectrophotometry. Since there is no official monograph, this dissolution test could be applied for quality control routine. |
Artigo Aplicação de fotólise direta e UV/H2O2 a efluente sintético contendo diferentes corantes alimentícios Marmitt, Sandro Pirotta, Lilian V. Stülp, Simone Resumo em Inglês: Food industries employ a lot of synthetic dyes in their products. Most of these dyes are very stable face to the conventional treatments. This work studied the use of advanced oxidation process (AOP) as an alternative to the conventional ones to degrade a synthetic food effluent (photolysis and UV/H2O2 in continuous reactor). The more efficient process was the UV/H2O2 and it presented decoloration and degradation energetic efficiency values equal to 30.775 kWh m-3 and 269.909 kWh m-3, respectively. The color reduction was 96.4% and COD decrease was 38.56%. |
Artigo Determinação de citrato de sildenafila e de tadalafila por cromatografia líquida de ultraeficiência com detecção por arranjo de diodos (CLUE-DAD) Ortiz, Rafael Scorsatto Antunes, Marina Venzon Linden, Rafael Resumo em Inglês: A simple ultra-performance liquid chromatographic method for the simultaneous determination of sildenafil citrate and tadalafil was developed and validated. Sample preparation was dissolution in methanol, followed by centrifugation and dilution (1:10) with methanol. Analysis was performed in an Acquity® UPLC system with Acquity® BEH C18 column (2.1 x 50 mm, with 1.7 μm particles). The elution was isocratic with phosphate buffer pH 2.3 and acetonitrile (65:35, v/v) at a flow rate of 0.7 mL/min. The method presented adequate specificity, linearity, precision and accuracy and allowed the determination of the drugs in seized forensic samples. |
Artigo Hidrólise do óleo de Azadirachta indica em água subcrítica e determinação da composição dos triacilglicerídeos e ácidos graxos por cromatografia gasosa de alta resolução a alta temperatura e cromatografia gasosa de alta resolução acoplada à espectrometria de massas Pinto, Jair Sebastião da Silva Lanças, Fernando Mauro Resumo em Inglês: The development of modern analytical tools plays an important role in quality control. The main purpose of this study was to explore the use of subcritical water as a versatile analytical tool, employed simultaneously as a reagent and solvent, as well as the application of high temperature-high resolution gas chromatography (HT-HRGC) to develop a procedure for the analysis of triacylglycerides and fatty acids in Azadirachta indica A. Juss. (Neem) oil without the need for solvents, chemical reagents, or catalytic agents. The developed method presented satisfactory results and is in agreement with the concepts of Green Analytical Chemistry (GAC). |
Artigo Estudo da eficiência de degradação de tetracloreto de carbono por plasma térmico e caracterização dos produtos formados Khalaf, Péricles Inácio Souza, Ivan Gonçalves de Carasek, Eduardo Debacher, Nito Angelo Resumo em Inglês: Decomposition of carbon tetrachloride in a DC thermal plasma reactor was investigated in argon atmosphere. The operational parameters such as plasma torch power and argon flow rate versus CCl4 conversion were examined. The CCl4 net degradation was determined by GC-FID, the chlorine produced was quantified by iodometric titration, the solid carbon was characterised by Raman spectroscopy and by BET analysis. The solid carbon collected inside de plasma reactor was submitted to solid/liquid extraction and the desorbed species were identified by GC-MS. |
Development of a flotation method for preconcentration-separation of trace amounts of some metal ions in plant tissues prior to their FAAS determinations Ghaedi, M. Shokrollahi, A. Montazerozohori, M. Marahel, F. Soylak, M. Resumo em Inglês: An efficient flotation method based on the combination of flame atomic absorption spectrometry (FAAS) and separation and preconcentration step for determination of Cr3+, Cu 2+, Co2+, Ni2+, Zn2+, Cd 2+, Fe3+ and Pb2+ ions in various real samples by the possibility of applying bis(2-hydroxyacetophenone)-1,4-butanediimine (BHABDI) as a new collector was studied. The influence of pH, amount of BHABDI as collector, sample matrix, type and amount of eluting agent, type and amount of surfactant as floating agent, ionic strength and air flow rates i.e. variables affecting the efficiency of the extraction system was evaluated. It is ascertained that metal ions such as iron can be separated simultaneously from matrix in the presence of 0.012 mM ligand, 0.025% (w/v) of CTAB to a test sample of 750 mL at pH 6.5. These ions can be eluted quantitatively with 6 mL of 1.0 mol L-1 HNO3 in methanol which lead to the enrichment factor of 125. The detection limits for analyte ions were in the range of 1.3-2.4 ng mL-1. The method has been successfully applied for determination of trace amounts of ions in various real samples. |
Recent research data on the removal of pharmaceuticals from sewage treatment plants (STP) Tambosi, José Luiz Yamanaka, Leonardo Yassuhiro José, Humberto Jorge Moreira, Regina de Fátima Peralta Muniz Schröder, Horst Friedrich Resumo em Inglês: Pharmaceutical compounds have been detected in sewage treatment plant (STP) effluents, surface waters and, less frequently, in groundwater and drinking water, all over the world. Different sources are responsible for their appearance in the aquatic environment, however, it is widely accepted that the main sources of this type of pollutant are STP effluents. The adverse effects of pharmaceuticals in the environment include aquatic toxicity, development of resistance in pathogenic bacteria, genotoxicity and endocrine disruption. Thus, the discharge of these compounds to the environment in STP effluents should be minimized. |
Revisão Os nanomateriais e a questão ambiental Paschoalino, Matheus P. Marcone, Glauciene P. S. Jardim, Wilson F. Resumo em Inglês: The increasing use of nanomaterials in several products in different areas such as electronics, cosmetics, food and drugs has attracted the attention of the scientific community due to unknown properties of these materials, such as the life cycle and the interaction with receptor organisms once they reach the environment. In this context, the present work shows an updated scenario of nanomaterials applications, characterization methods and toxicity evaluation, also addressing important aspects related to the development and application of nanotechnology under the environmental point of view. |
Revisão Modificação bioquímica da gordura do leite Nunes, Gisele Fátima Morais Paula, Ariela Veloso de Castro, Heizir Ferreira de Santos, Júlio César dos Resumo em Inglês: Recent advances for improving physicochemical and nutritional properties of lipids are reviewed, with emphasis on products attaining by biochemical processing of natural fats and oils. Enzymatic interesterification provides an important route to modify physical and nutritional properties of milkfat without generating trans isomers. This process makes use of lipases, a versatile class of enzyme that is able to perform efficiently the target modification in both solvent and solvent free systems. The present review covers important features of lipases, lipase-catalyzed interesterification reactions and their effects on the composition and texture of the resulting product. |
Revisão Blendas de PHB e seus copolímeros: miscibilidade e compatibilidade Quental, Antonio Carlos Carvalho, Fabiana Pires de Tada, Eduardo dos Santos Felisberti, Maria Isabel Resumo em Inglês: Poly(hydroxybutyrate) and its copolymers are linear polyesters behaving as conventional thermoplastic materials. However, they are totally biodegradable and produced by a wide variety of bacteria from renewable sources. Some properties and high production cost are still preventing future applications. In an attempt to improve the properties and to reduce cost blending PHB with others polymeric materials is one of the most efficient method. In this paper, miscibility, compatibility, morphological and mechanical aspects of PHB blends will be reviewed. An extensive revision over twenty last years was realized about works of blends based on PHB and its copolymers. |
Determination of free urinary cortisol in cushing's syndrome using reversed-phase high performance liquid chromatography Sugawara, Eduardo Kinio Ribeiro Neto, Luciane Maria Verreschi, Ieda Terezinha do Nascimento Resumo em Inglês: Determination of free urinary cortisol is a test of choice in the diagnosis of Cushing's syndrome. In this study, cortisol was quantified using reversed-phase high-performance liquid chromatography (RP-HPLC) in urine samples previously extracted with ether and using triamcinolone acetonide as internal standard (IS). A BDS-Hypersil-C18® column, water-acetonitrile (72:28; v/v), with a flow rate of 1.0 mL/min and detection at 243 nm were used. This method showed to be both effective and efficient, with sensitivity and linearity ranging from 2.50 to 150 μg/L, and can be used in substitution to the radioimmunoassay technique within this concentration range. |
Nota técnica Distribuição espacial de compostos orgânicos de estanho em sedimentos costeiros e em Phallusia nigra da Baía de Todos os Santos e litoral norte da Bahia - Brasil Pletsch, Adelmo Lowe Beretta, Magda Tavares, Tania Mascarenhas Resumo em Inglês: Organic tin compounds were investigated in the sediment of twenty-four stations located in the Todos os Santos Bay and the north coast of Bahia - Brazil. The concentration of these organic tin was also determined in a ascidium species of Phallusia nigra. The speciation and quantification was performed by GC-MS/MS. The highest concentrations were: tributyltin (TBT) 438 ng g-1, dibutyltin (DBT) 207 ng g-1, monobutyltin (MBT) 423 ng g-1, diphenyltin (DPT) 25.8 ng g-1 and monophenyltin (MPT) 55.0 ng g-1. DBT and MBT were found in Phallusia nigra, with highest concentrations of 294.1 and 148.5 ng g-1, respectively. |
Removal of copper(II) from sugar-cane spirits employing chitosan Janegitz, Bruno C. Oliveira, Andrea Gomes, Marcos S. Sartori, Elen R. Pereira-Filho, Edenir R. Fatibello-Filho, Orlando Resumo em Inglês: A method employing chitosan as complexant agent in the removal of copper(II) ions generally present in the Brazilian cachaça samples is herein proposed. The efficiency of this method is attributed to its high capacity of metal cations adsorption, mainly due to presence of hydroxyl and amine groups that can serve as chelating sites. The removal of copper(II) ions from this alcoholic beverage was efficient employing either in column and batch system. The analysis were carried out employing the flame atomic absorption spectrometry and the remaining copper(II) concentrations in the treated cachaça were lower than LOD of FAAS technique. |
Nota técnica Desenvolvimento de um método reflectométrico ambientalmente mais amigável para a determinação de metoclopramida em formulações farmacêuticas Doretto, Keity Margareth Gotardo, Mara Andréia Pezza, Helena Redigolo Pezza, Leonardo Resumo em Inglês: A simple and more environmentally friendly method by combined spot test-diffuse reflectance spectroscopy for determining metoclopramide in pharmaceutical formulations is described. The method is based on the reaction between metoclopramide and p-dimethylaminocinnamaldehyde, in the presence of HCl, producing a colored compound (λmáx = 580 nm) on the filter paper. The linear range was from 5.65 x 10-4-6.21x10-3 mol L-1 (r = 0.999). The limit of detection was 1.27 x 10-4 mol L-1. The proposed reflectometric method was applied successfully to the determination of metoclopramide in pharmaceuticals and it was favorably compared with the Brazilian or British Pharmacopoeia methods at 95% confidence level. |
Nota técnica Estratégias de pré-concentração em eletroforese capilar: parte 2. Manipulação da velocidade da fase dispersa/secundária Moraes, Maria de Lourdes L. de Tavares, Marina F. M. Pereira, Elisabete A. Resumo em Inglês: This work describes CE preconcentration strategies based on the effect of manipulation of the disperse/secondary velocity. Introduced by Terabe et al. in 1984, micellar electrokinetic chromatography is a powerful separation approach that increases the usage of electrokinetic phenomena for the separation of nonionic compounds. The main disadvantage of MEKC is the low concentration sensitivity associated with the limited optical path length for on-capillary photometric detection and the limited volume of sample solution that can be injected. This paper compiles on-line concentration strategies for neutral analytes by sample stacking and sweeping in micellar electrokinetic chromatography. |
Nota técnica Determinação de olanzapina em formulações farmacêuticas por espectrofotometria: desenvolvimento e validação Rêgo, Jardes Figuerêdo do Moura, Jacira Izidório de Moita, Graziella Ciaramella Resumo em Inglês: Spectrophotometric methods of zero order, first and second derived order had been developed for olanzapine determination in tablets using ethanol and isopropanol as solvent. The two solvents revealed to be adequate. For the three methods the calibration curve coefficient of correlation had been greater than 0.9998 with limit of detection varying from 0.068 to 0.190 mg L-1, in ethanol, and 0.026 to 0.205 mg L-1, in isopropanol. The inter-day precision was inferior to 1.1 and 1.9 mg L-1 for ethanol and isopropanol, respectively. The average recoveries varied from 98 to 101%, in ethanol and 99 to 103% in isopropanol. |
Development of new dissolution test and HPLC-RP method for anti-parasitic ornidazole coated tablets Soares, Mônica Felts de La Roca Soares Sobrinho, José Lamartine Grangeiro Júnior, Severino Silva, Keyla Emanuelle Ramos da Alves, Lariza Darlene Santos Rolim Neto, Pedro José Resumo em Inglês: This work aimed the development and validation of a new dissolution test for ornidazole coated tablets. The dissolution conditions were determined after testing Sink conditions, dissolution medium, apparatus, stirring speed, 24 h stability and medium filtration influence. The best conditions were paddle at a stirring speed of 75 rpm and 900 mL of 0.1 M HCl. A new HPLC quantification method was developed and validated. The dissolution test and quantification method showed to be adequate for their purposes and could be applied for quality control of ornidazole coated tablets, since there is no official monograph. |
Educação Determinação da entalpia de vaporização de líquidos pelo método do isoteniscópio de Smith e Menzies Gerola, Adriana Passarella Peloi, Lilian Somenci Hioka, Noboru Santin Filho, Ourides Kato, Lilian Akemi Resumo em Inglês: This article proposes an experimental procedure to determine the enthalpy (and entropy) of vaporization of organic liquid compounds, by the Smith-Menzies (isoteniscope) method. The values of vapor pressure at different temperatures were obtained and ΔvH (and ΔvS) were graphically determined, using the Clausius-Clapeyron equation. The results for diethyl-ether, propanone, ethanol and n-hexane are in very good agreement with those from literature. A historical and thermodynamic discussion on equations that correlates vapor pressures and temperature precedes the experimental proposition. |
Assuntos gerais Produtividade em pesquisa do CNPq: análise do perfil dos pesquisadores da Química Santos, Natacha Carvalho Ferreira Cândido, Lucilene Faustina de Oliveira Kuppens, Cristiano Lima Resumo em Inglês: The profile of the CNPq Research Productivity Program in Chemistry was studied using the Plataforma Lattes curricula of all researchers with grants in effect as of March 2009. Most of them are male (67.2%), working in Federal Universities (59.4%) and located in Southeastern Brazil (63.7%). There is no evident homogeneity among researchers of the same level/category concerning the productivity criterions used (the H index and the scientific productivity of the last five years). CNPq and the Chemistry Assessor Committee have been focusing on making their judgments unbiased, by using quantitative parameters, but such overlap is still noticeable. |