Time filter

Source Type

Packer A.P.,EMBRAPA - Empresa Brasileira de Pesquisa Agropecuária | Sarkis J.E.S.,Brazilian Nuclear Energy Research Institute (IPEN) | Dos Santos E.J.,Institute Tecnologia Do Parana Tecpar
Journal of the Brazilian Chemical Society | Year: 2014

The presence of some inorganic elements in biodiesel can compromise the fuel quality and enhance the emission of pollutants. In this context, a new procedure for biodiesel sample preparation using a high pressure asher (HPA) is presented, aiming the determination of Al, Ca, Cu, Fe, K, Mg, Mn, Na, Ni, P, Sr, and Zn, in soybean, sunflower, animal fat, cotton and castor oil, by inductively coupled plasma optical emission spectrometry (ICP OES). The digestion conditions of the HPA were optimize to digest 1.5 g of biodiesel, with HNO3 and H2O2, at a temperature of 300 °C and pressure of 435 psi, which considered the sample dilution factor, the total solids in solution and the acidity for ICP OES determinations. Analytes concentrations in these biodiesels were calculated using standard addition method. Detection limits from 0.05 to 0.7 mg kg-1 were suitable to attend biodiesel quality parameters, government policy and legislations worldwide. Therefore, the proposed procedure proved to be efficient to eliminate the major organic interferences typically present in oil based samples allowing a fast, precise, interference-free and robust analytical condition for biodiesel characterization. © 2014 Sociedade Brasileira de Química.

Barison A.,Federal University of Paraná | Da Silva C.W.P.,Federal University of Paraná | Campos F.R.,Federal University of Paraná | Simonelli F.,Federal University of Paraná | And 2 more authors.
Magnetic Resonance in Chemistry | Year: 2010

A simple methodology for the determination of the fatty acid composition of edible oils through 1H NMR is proposed. The method is based on the fact that all fatty acid chains are esterified to a common moiety, glycerol, and the quantification is done directly in the 1H NMR spectra through the relationship between the areas of a characteristic signal of each fatty acid and a signal of the glycerol moiety, without the use of mathematical equations. The methodology was successfully applied to determine the fatty acid composition of several edible oils, with equivalent results to those given by the AOAC Official method by gas chromatography. Itsmain advantages are simplicity and the lack of need for sample pre-treatment such as derivatization or extraction. Copyright © 2010 John Wiley & Sons, Ltd.

Leite N.F.,Institute Tecnologia do Parana TECPAR | Peralta-Zamora P.,Federal University of Paraná | Grassi M.T.,Federal University of Paraná
Journal of Environmental Sciences | Year: 2011

The concentrations of 16 polycyclic aromatic hydrocarbons (PAHs) were determined in surface sediment samples from nine sites located at the Iguaçu River Basin in the Metropolitan Region of Curitiba, Brazil to evaluate their distribution and sources. The total concentration of the PAHs was greater for sediments from highly urbanized areas, while the sediments from the Iraí Environmental Protection Area (Iraí EPA) showed significantly low concentrations. The sediments from the Iguaçu and Barigui rivers were classified as highly contaminated, while those from the Cercado and Curralinho rivers were classified as moderately contaminated. The predominance of PAHs containing two to four aromatic rings in most of the samples suggested the direct input of raw sewage into the water resources evaluated. Benzo[g,h,i]perylene, dibenzo[a,h]anthracene and indeno[1,2,3-cd]pyrene were predominant in sediments from the areas under the greatest urban and industrial development. The correlation between thermodynamic stability and the kinetics of evolution presented by the isomeric pairs indicated that combustion is the predominant source of PAHs in the sediments because the combustion of fossil fuels affected most of the points evaluated, followed by combustion of biomass and eventually combustion of oil product inputs. In general, the results showed that areas under strong urban influence, as well as the Iraí EPA, receive contributions of PAHs from similar sources. © 2011 The Research Centre for Eco-Environmental Sciences, Chinese Academy of Sciences.

Bolognesi L.,Institute Tecnologia Do Parana TECPAR | Santos E.J.D.,Institute Tecnologia Do Parana TECPAR | Abate G.,Federal University of Paraná
Chemical Papers | Year: 2015

A method for the determination of formaldehyde by flow injection analysis with spectrophotometric detection is proposed, based on retarding the reaction between brilliant green and sulphite by the addition of formaldehyde; this was investigated for formaldehyde quantification in extracts from wood-based panels. For the first time, a heating step was explored, providing a sample throughput of 50 analyses per hour, with a limit of detection of 0.02 mg L-1 and linearity of 0.20-3.0 mg L-1, which was adequate for the expected range of formaldehyde concentration in the extracts. The mean recovery observed for actual samples was in the range of 92-106 %, with a maximum relative standard deviation of 6.0 %. The paired t-test revealed no significant difference between this method and the official Nash method, demonstrating an appropriate accuracy and precision; the method is proposed as a simple, fast and inexpensive alternative for the routine determination of formaldehyde in an aqueous medium. © 2015 Institute of Chemistry, Slovak Academy of Sciences.

PubMed | Institute Tecnologia do Parana Tecpar and Federal University of Paraná
Type: Journal Article | Journal: PloS one | Year: 2015

In previous work, a new lipase and its cognate foldase were identified and isolated from a metagenomic library constructed from soil samples contaminated with fat. This new lipase, called LipG9, is a true lipase that shows specific activities that are comparable to those of well-known industrially-used lipases with high activity against long-chain triglycerides. In the present work, LipG9 was co-expressed and co-immobilized with its foldase, on an inert hydrophobic support (Accurel MP1000). We studied the performance of this immobilized LipG9 (Im-LipG9) in organic media, in order to evaluate its potential for use in biocatalysis. Im-LipG9 showed good stability, maintaining a residual activity of more than 70% at 50 C after incubation in n-heptane (log P 4.0) for 8 h. It was also stable in polar organic solvents such as ethanol (log P -0.23) and acetone (log P -0.31), maintaining more than 80% of its original activity after 8 h incubation at 30 C. The synthesis of ethyl esters was tested with fatty acids of different chain lengths in n-heptane at 30 C. The best conversions (90% in 3 h) were obtained for medium and long chain saturated fatty acids (C8, C14 and C16), with the maximum specific activity, 29 U per gram of immobilized preparation, being obtained with palmitic acid (C16). Im-LipG9 was sn-1,3-specific. In the transesterification of the alcohol (R,S)-1-phenylethanol with vinyl acetate and the hydrolysis of the analogous ester, (R,S)-1-phenylethyl acetate, Im-LipG9 showed excellent enantioselectivity for the R-isomer of both substrates (E> 200), giving an enantiomeric excess (ee) of higher than 95% for the products at 49% conversion. The results obtained in this work provide the basis for the development of applications of LipG9 in biocatalysis.

Chaves E.S.,Federal University of Santa Catarina | dos Santos E.J.,Institute Tecnologia do Parana TECPAR | Araujo R.G.O.,Federal University of Sergipe | Oliveira J.V.,URI Integrated Regional University Brazil | And 2 more authors.
Microchemical Journal | Year: 2010

Methods for the determination of 5 major (Ca, K, Mg, Na and P) and 14 minor elements (Al, Ba, Cd, Co, Cu, Fe, Ga, Mn, Mo, Ni, Pb, Rb, Sr and Zn) in vegetable seeds by ICP OES and by ICP-MS, respectively, are proposed. After a common sample preparation consisting of smashing and homogenization in an agata mortar, followed by acid digestion in a microwave oven, the diluted sample solutions were measured in the spectrometers using conventional pneumatic nebulizers. External calibration with aqueous standard solutions was used for both techniques. Internal standard was not required, due to the absence of non-spectral interference. For the major elements, the detection limits were in the range of 0.01 (Mg) to 0.3μgg-1 (Na and K) and for the minor elements they were in the range of 0.001 (several) to 0.4μgg-1 (Fe). The detection limits were adequate for the seed analysis. The accuracy was validated by analyzing a botanical certified reference material (Pine Needles). Agreement of the concentrations with the certified or informed values was obtained, according to the t-test for a confidence level of 95%. The relative standard deviations were below 10% indicating an adequate precision. Seeds from seven different plants were analyzed: cotton seed, sunflower, castor bean, fodder turnip, curcas bean, soybean and tung. The element concentrations varied considerably in the different samples. The results were also evaluated using the principal component analysis. © 2010 Elsevier B.V.

Dos Santos E.J.,Institute Tecnologia Do Parana TECPAR | Herrmann A.B.,Institute Tecnologia Do Parana TECPAR | Dos Santos A.B.,Institute Tecnologia Do Parana TECPAR | Baika L.M.,Institute Tecnologia Do Parana TECPAR | And 4 more authors.
Journal of Analytical Atomic Spectrometry | Year: 2010

A simple and fast method is described for the determination of Hg, present as thimerosal, in vaccines by photochemical vapor generation coupled to axial view inductively coupled plasma optical emission spectrometry. Mercury emission was detected at 253.652 nm. No sample treatment was necessary other than simple dilution and addition of 10% v/v formic acid. Vapor generation conditions were optimized and included formic acid concentration, sample flow rate, reactor tube dimensions and argon flow rate. External calibration was achieved using aqueous standard solutions of Hg2+ containing 10% v/v formic acid. The detection limit (3 s, n = 10) was 0.3 g L-1 of Hg or 0.6 g L -1 of thimerosal in solution, equivalent to 60.0 g L-1 of thimerosal in the original vaccine solution or 0.03 g of thimerosal per dose. The procedure was applied to the analysis of anti-rabies, diphtheria/tetanus, hepatitis B and influenza vaccines, sourced from two producers. Thimerosal was present in the vaccines within a narrow range of 47.4 ± 0.4 to 53.7 ± 0.7 g per dose (0.5 mL vaccine), in agreement with product information, except for the influenza vaccine from one of the producers, for which the thimerosal mass per dose was below the detection limit. Recoveries of 93-102% demonstrated the robustness of the methodology. Precision, expressed as relative standard deviation, yielded 2.9% under conditions of repeatability and 4.4% for reproducibility. This simple procedure is currently adopted by Tecpar (Curitiba, Brazil) to control the amount of thimerosal in anti-rabies vaccines. © 2010 The Royal Society of Chemistry.

dos Santos E.J.,Institute Tecnologia do Parana TECPAR | Herrmann A.B.,Institute Tecnologia do Parana TECPAR | Vieira F.,Institute Tecnologia do Parana TECPAR | Sato C.S.,Institute Tecnologia do Parana TECPAR | And 4 more authors.
Microchemical Journal | Year: 2010

Mercury and lead were determined in an extraction solution applied to compact fluorescent lamps by axial view inductively coupled plasma optical emission spectrometry (ICP OES). The solution contained 50% v/v HNO3 and 10% v/v H2O2. The compact fluorescent lamps were treated by removing the socket and breaking the rest of the lamp inside the solution, followed by placing the mixture in an ultrasonic bath for 1h. The mixture was filtrated in a coarse paper filter and the resulting extraction slurry was analyzed. The determination of Pb in the slurry required calibration by the analyte addition technique, while for Hg, external calibration was adequate. The quantification limits (10s, n=7), for Hg (194.164nm) and Pb (220.353nm) were, respectively, 10 and 30μg per lamp. Analysis of spiked samples demonstrated reasonable accuracy of the method, with recoveries in the range from 99 to 120% for Hg and from 91 to 107% for Pb. Fifteen analyzed samples showed Hg masses per lamp in the range from 1.6 to 27mg, and six samples were above the limit allowed by the European Community that is 5mg per compact lamp. The values for Pb were between 0.07 and 0.75mg per lamp. By filtrating the slurry in a membrane filter, and analyzing the resulting solution, it was found that all Hg was extracted to the liquid phase of the slurry, while a fraction of about 40% m/v of Pb is retained in the solid particles. The lamp cover glass, after extraction of the phosphor layer, was also analyzed for Hg and Pb. The concentration of Hg in the glass is quite low; however, the Pb content is high. © 2010 Elsevier B.V.

dos Santos E.J.,Institute Tecnologia do Parana TECPAR | Herrmann A.B.,Institute Tecnologia do Parana TECPAR | Prado S.K.,Institute Tecnologia do Parana TECPAR | Fantin E.B.,Institute Tecnologia do Parana TECPAR | And 3 more authors.
Microchemical Journal | Year: 2013

A simple and rapid method for the simultaneous determination of As, Sb and Pb in glass beads used for pavement markings on highway surfaces by axial view inductively coupled plasma optical emission spectrometry is presented. Three sample preparation approaches using a 3:1 mixture of HNO3 and HF were evaluated: (01) an open beaker approach; (02) a microwave-assisted digestion system, based on EPA method 3052 and (03) an ultrasound-assisted digestion. To react with the excess of residual fluoride, H3BO3 and ZrOCl2 were investigated. Spectral interference was evident when ZrOCl2 was used for determination of As. Ultrasound-assisted digestion using 3mL of HNO3 and 1mL of HF for 1h at 40kHz followed by addition of H3BO3 was chosen for in-depth study. Quantification limits (10s, n=10) based on a 0.1g subsample diluted to 50mL were: 30mgkg-1 for As (193.696nm), 10mgkg-1 for Sb (206.834nm) and 5mgkg-1 for Pb (220.353nm). Analysis of spiked samples provided recoveries in the range of 87 to 104% for all analytes. Of nineteen Brazilian and imported samples analyzed, As was present above the quantification limit in five, Sb in one and Pb in almost all. Some samples, all imported, showed values above the limit allowed by the Brazilian legislation, i.e., 200mgkg-1 for As, Sb and Pb. Solubility tests showed high levels of As leaching for all imported samples, above the specification limit. Leachability tests showed that the glass beads cannot be classified as toxic materials; however, the release of potentially toxic elements could cause some environmental risks. © 2012 Elsevier B.V.

Da Silva E.J.,Federal Technological University of Paraná | Torquato E.,Pontifical Catholic University of Parana | Ramos M.P.,Institute Tecnologia do Parana TECPAR | Paraiso E.C.,Pontifical Catholic University of Parana
Proceedings - 2013 IEEE International Conference on Systems, Man, and Cybernetics, SMC 2013 | Year: 2013

Collaboration is an important issue when developing software, because it involves working together towards a common goal. This work presents OPERAM, a collaborative semantic workspace that allows comparing the modeling performed at earlier stages of software development with JAVA code. OPERAM provides useful information for professionals involved in the task of developing code and even managing the project. OPERAM aims to allow monitoring of the project, helping users to be aware of the context they are working, allowing carry out verification of software development, confronting the modeling performed with source-code produced during the programming phase. We present its main features and architecture. In this paper the main features and architecture of OPERAM are presented, as well as a validation was conducted to prove the effectiveness of OPERAM. The results show the value of the workspace as a tool to support collaboration and software verification. © 2013 IEEE.

Loading Institute Tecnologia do Parana TECPAR collaborators
Loading Institute Tecnologia do Parana TECPAR collaborators