Programa de Pós-graduação em Química

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Síntese e caracterização de nanopartículas de maguemita recobertas com sílica funcionalizada com grupos amina
(Universidade Federal de Goiás, 2008-11-25) ALMEIDA, Michelly Patrícia Santana de; SARTORATTO, Patrícia Pommé Confessori; http://lattes.cnpq.br/9777959525393785
Magnetic nanoparticles coated with several kinds of materials have been the focus of intense research due to their potential applications in biomedicine. This type of material contains a magnetic core that is involved by a shell of different composition. The coating of magnetic nanoparticles with amino-functionalized silica is particularly important because of its reactivity which allows the coupling with biological molecules such as fragments of DNA, antibodies, proteins, among others. In this work, maghemite nanoparticles were coated with silica and with amino-functionalized silica, the incorporation of them being achieved by using tetraethoxysilane (TEOS) and aminopropyltrimethoxysilane (APTS) as the precursors of the sol-gel system. Firstly, the magnetic fluids of maghemita were prepared and afterwards they were employed in the silica-coating procedures which were based on the Stöber method. Some experimental parameters were varied, such as the number of maghemita nanoparticles, pH of the reaction medium, time of reaction and amount of TEOS, with the aim of modulating the characteristics of the solids and obtaining stable aqueous suspensions of the materials. All products were analyzed by the following techniques: X- ray diffraction, diffuse reflectance infrared spectroscopy, dynamic light scattering, electrophoretic mobility (zeta potential) and transmission electron microscopy.
Ressonância Magnética Nuclear e quimiometria como ferramentas de distinção e quantificação de metabólitos de cana-de-açúcar (Saccharum officinarum) e feijão-comum (Phaseolus vulgaris)
(Universidade Federal de Goiás, 2010-06-11) ALVES FILHO, Elenilson de Godoy; ALCANTARA, Glaucia Braz; http://lattes.cnpq.br/6408676855110487; LIÃO, Luciano Morais; http://lattes.cnpq.br/2647529909397336
Five different common beans cultivars (Phaseolus vulgaris) in the raw conditions, after water immersion (soaking) and after domestic processing (cooking), were studied by NMR in solution and HR-MAS NMR, to obtain a protocol that quantify the oligosaccharides raffinose, stachyose and verbascose contents in bean seeds. The looking for low contents of these oligosaccharides in bean seeds is inserted in Embrapa Arroz e Feijão objectives. This study describes yet the potentiality of chemometric analysis applied in 1H HR-MAS NMR and in solution NMR for investigation of sugarcane varieties. Sugarcane is a primordial material used in Brazil for production of ethanol biofuel. Several technologies to development of new sugarcane cultivars have mainly focused the increase of productivity and greater disease resistance. Sugarcane cultivars are usually identified by organography of leaves and stems, as well as the analysis of peroxydase and esterase isoenzyme activities, soluble total protein and soluble solids content. In this work eight different cultivars of sugarcane leaves were analyzed: RB72454, RB835054, RB835486, RB855113, RB855156, RB855453, RB855536 and RB867515. NMR and chemometric analysis showed useful tools for distinction of the different sugarcane cultivars. In addition, these techniques successfully demonstrated the chemical differences about the investigated cultivars, specially the sugar contents.
Estudo estrutural por 1h-rmn de peptídeos bioativos isolados da secreção cutânea de Hypsiboas Albopunctatus E Leptodactylus Labyrinthicus
(Universidade Federal de Goiás, 2012-02-24) ALVES, Eliane Santana Fernandes; LIÃO, Luciano Morais; http://lattes.cnpq.br/2647529909397336
Currently, the emergence of fungi, bacteria and viruses resistant to multiple drugs has stimulated interest in the development of antimicrobial peptides with increased therapeutic potential. They generally have properties of extreme importance as antimicrobial selective toxicity, rapid action, specific mechanisms of action and a broad spectrum of antimicrobial action. Many of these features can be found in peptides isolated from frog skin secretions. The main factor that differentiates antimicrobial peptides from other commonly antibiotics used in the conventional therapy is related to their mechanism of action. The driving force for much of the action of antimicrobial peptides is their ability to lysis cell membranes, rapidly killing a broad spectrum of microorganisms. Accordingly, the conformation of the peptide has a great importance in their interaction with the amphiphilic structure of biological membranes. The determination of the tridimensional structure by Nuclear Magnetic Resonance (NMR) technique allows the identification of the spatial position of each amino acid residue and highlighting those that are important for its action and, therefore, could be modified to increase the antimicrobial activity. The study of the three-dimensional structure of peptides in solution is an advantage of the NMR spectroscopy, since it can simulate the physiological environment, by means of surfactants. In this context, the tridimensional structures of two synthetic peptides: ocellatin-P1G16 (GLLDTLKGAAKNVVGGLASKVMEKL-NH2), isolated from the amphibians Leptodactylus labyrinthicus, and hylin a1 (IFGAILPLALGALKNLIK-NH2), isolated from Hypsiboas Albopunctatus, were proposed by NMR. The amphipathic caracter can be visualized by separation of the helix into two distinct sides, one hydrophobic (nonpolar) and the other hydrophilic (polar). The peptide hylin a1 in presence of SDS-d25 showed helical structure between residues Ile-5 to Ile-17 and the peptide ocellatin-P1G16 in SDS-d25 micelles showed a α-helical structure between residues Leu-3 to Lys-24, both are presented in amphipathic α-helix Finally, the molecular analyses of amphipathicity, electrostatic interaction, polarity and exchange hydrogen/deuterium, corroborate the proposed model, suggesting a model of parallel orientation to the peptide hylin a1 and the peptide ocellatin-P1G16 a parallel orientation, but with the cterminal portion immersed in the micelle SDS-d25 between residues Ser-19 to Leu-25, as observed by analyzing exchange hydrogen/deuterium. These structural characteristics make these peptides promising candidates for the development of a new antimicrobial drug.
Síntese, caracterização e estudo das propriedades magnéticas do Zn1-xFexO (0,00 ≤ x ≤ 0,09) produzido por reação de combustão
(Universidade Federal de Goiás, 2010-11-25) ALVES, Thiago Eduardo Pereira; FRANCO JÚNIOR, Adolfo; http://lattes.cnpq.br/0187547195548392
In this work compounds Zn1-xFexO, with 0.00 ≤ x ≤ 0.09, were synthesized by combustion reaction method with two different heating processes, in a thermal blanket and muffle furnace. Chemical analysis of compounds was performed by atomic absorption spectroscopy (AAS) and Fourier transform infrared (FTIR). Structural analysis of the crystalline phase, the diameter of the crystallites and the lattice parameters were checked by X-ray diffraction (XRD, powder method) and refinement software (Unitt and powder X cell). The analysis of surfaces and morphologies were determined by adsorption and desorption of N2 (ASAP, BET model) and transmission electron microscopy (TEM). Finally, Magnetic measurements were performed by vibrating sample magnetometer (VSM). The stoichiometric determined by atomic absorption is in good agreement with the calculated value for all samples. The samples were synthesized in a thermal blanket which corresponds to the wurtzite crystal structure with no secondary phases. The samples synthesized in furnace had wurtzite crystal structure, however, showed a small sample to phase segregation above 5%. The second phases are found with spinel phase indicate that the formation of zinc ferrite. The data of thermal analysis, infrared and X-ray diffraction, we show that the synthesis product in blanket form moving slowly in several stages, while that in the synthesis furnace gets the product directly. We noted the tendency of the formation of smaller particles for the samples from the thermal blanket, as well as high surface areas for these samples, those prepared in a muffle grating. Images by transmission electron microscopy confirm the observations made by x-ray diffraction measurements of surface areas by BET model. The magnetic measurements show ferromagnetic phenomenon only for the sample produced in a muffle. The saturation magnetization was calculated by extrapolation, and their values are promising when compared with the literature. The Curie temperatures were estimated for some samples and all values were well above room temperature.
Aplicação de métodos quimiométricos para a classificação de águas minerais comercializadas em Goiânia-GO
(Universidade Federal de Goiás, 2010-08-27) BORGES FILHO, Dorivan; SOUZA, Paulo Sérgio de; http://lattes.cnpq.br/0834231763464061
Síntese e caracterização de catalisadores de óxido de ferro suportado em titanatos lamelares
(Universidade Federal de Goiás, 2008-05-19) BRASIL, Valéria Bacelar; NUNES, Liliane Magalhães; http://lattes.cnpq.br/6591210839894513
Sodium trititanate and silica - trititanate supported iron oxide catalysts were prepared by coprecipitation of iron ions and by the deposition of iron oxide nanoparticles previously prepared. The catalysts and the supports were characterized regarding their composition, structure, thermal behavior and textural properties. The amount of iron in catalysts ranged from 0.98% to 5.9%, and the lowest percentages were observed for catalysts prepared by deposition of nanoparticles. The catalysts and supports are macroporous with limited mesoporosity. The catalysts and supports were evaluated in the reaction of dehydrogenation of ethylbenzene for the production of styrene. During tests, the structure of the solids did not chang. Both the supports and the catalysts were active in the dehydrogenation of ethylbenzene in the absence of steam, allowing the economy of energy. The results of verification of the ionic exchange process/ adsorption of Cu+2, showed that the solids containing iron oxide in the composition presented results higher than the solids without iron oxide. The exception was observed for the solids that have acid surface.
Influência do biótipo de cor de fruto e da sazonalidade no óleo essencial das folhas Eugenia uniflora
(Universidade Federal de Goiás, 2009-03-27) COSTA, Deomar Plácido da; FERRI, Pedro Henrique; http://lattes.cnpq.br/2129799749473005
The multivariate chemical analysis of the essential oils from leaves of Eugenia uniflora with different fruit colour indicated the presence of three clusters of oils regarding sample biotypes. The first included yellowish-orange, purple, and dark red fruits with high percentages of germacrene B (11-31%), germacrone (9.8-54%) and atractylone (0-20%). In cluster II, with red bright fruit samples, the major constituents were curzerene (42-43%), germacrene D (8.7- 9.0%) and germacrene A (5.9-8.9%), while cluster III included red-orange fruit samples containing a high content of selina-1,3,7(11)-trien-8-one (40-55%) and selina-1,3,7(11)-trien-8-one epoxide (13-24%). All essential oils have predominantly sesquiterpenes, although sesquiterpene hydrocarbons and oxygenated sesquiterpenes contents were majorities in the clusters I/II and III, respectively. In addition, seasonal influence on the chemical composition of essential oils of from leaves of red-orange fruit colour biotype has indicated the influence of seasons, which included samples collected during dry months (April-September) characterized by the highest percentages of spathulenol (10%) and caryophyllene oxide (4.1%), and samples collected during wet months (October-March), whose major constituent was selina-1,3,7(11)-trien-8- one epoxide (29%). The canonical correlation indicated that spathulenol and caryophyllene oxide revealed a strong relationship with the phenolics and nutrient balance (S, Ca, Fe) in leaves, whereas selina-1,3,7(11)-trien-8-one epoxide was related to (K, Cu, Mn), and precipitation during the months of the wet season. Oxygenated sesquiterpenes were predominant in all the sampling months and the oil chemovariation observed might be environmentally determined by a clear seasonal influence.
Preparo e modificação química de látex magnético à base de nanocompósitos de ferrita de cobalto e poliestireno
(Universidade Federal de Goiás, 2009-12-15) CRUZ, Fábio Pereira da; RABELO, Denilson; http://lattes.cnpq.br/4961539278604455
In this work, magnetic nanocomposites based on cobalt ferrite/polystyrene with aproximately 30 % of encapsulated ferrite and average diameter of 100 nm were prepared through miniemulsion polymerization with poly(vinyl alcohol) (PVA) as emulsifying agent. The cobalt ferrite was synthesized through coprecipitation technique followed by the formation of hydrophobic gel constituted of nanoparticles surfactated with oleic acid. Ferrite gel was separated by simple filtration and directly dispersed in styrene monomer for encapsulation, even after drying and storage for several days. After ferrite gel dispersion in styrene, it was produced a miniemulsion in water through mechanical agitation with high speed in the presence of PVA. This system was polymerized at 70 oC with sodium persulfate as initiator. The grafting of PVA on polystyrene surface was investigated. The hydroxyl groups of PVA on the surface of cobalt ferrite/polystyrene nanocomposite were esterified in aqueous medium with stearic acid and dodecylbenzene sulfonic acid as catalyst and surfactant directly in polymerization reactor. Cobalt ferrite nanoparticles in the form of powder and gel, magnetic cobalt ferrite/polystyrene nanocomposites non-esterified and esterified were characterized by thermogravimetric analysis and differential thermal analysis (TG/DTA), infrared spectroscopy (FTIR), ultraviolet-visible spectroscopy, X-ray diffraction, transmission electron microscopy (TEM) and dynamic light scattering. Dispersions in mineral oil of CoFe2O4 gel and CoFe2O4/polystyrene nanocomposite esterified with concentrations of 0,05%; 0,1%; 0,2%; 0,5% e 1,0% (w/v) were characterizated by particle size distribution and stability. The presence of NaCl in CoFe2O4 gel and in CoFe2O4/polystyrene nanocomposite esterified induced corrosion reactions of CoFe2O4 nanoparticles at high temperatures during TG/DTA analysis. NaCl contamination also prevented the correct determination of CoFe2O4 content in the gel and in the esterified nanocomposite. The nanofluid with 1% of CoFe2O4/polystyrene nanocomposite esterified was more stable than all nanofluids of ferrite gel. The presence of agglomerates in mineral oil dispersion of CoFe2O4 gel and CoFe2O4/polystyrene nanocomposite esterified can be due the presence of NaCl and the inefficiency of mechanical dispersion process
Estudo da adsorção de íons ortofosfato em hidróxido de alumínio
(Universidade Federal de Goiás, 2009-05-26) DAMASCENO, Fernando Cruvinel; LIMA, Emilia Celma de Oliveira; http://lattes.cnpq.br/0176904550618260
Aluminum hydroxides are efficient phosphate adsorbents. In this work it was investigated the adsorptions of phosphate in three different forms of aluminum hydroxide (amorphous, bayerite and pseudo-boehmite). The adsorption isotherms present the amount of phosphate adsorbed as a functions of the equilibrium concentration of orthophosphate ions aqueous solutions, in pH = 5. The products of adsorption were characterized by infrared spectroscopy, 27Al e 31P NMR spectroscopy, XRD analysis, and by zeta potential measurements of the aqueous dispersions. The adsorption isotherms of phosphate on aluminum hydroxide showed that when the hydroxides are treated with diluted phosphate solutions (< 2,0 mmolL-1) the three hydroxides adsorb similar amount of phosphate. When the hydroxides are treated with concentrated phosphate solutions (> 2,0 mmolL-1) bayerite and amorphous aluminum hydroxide incorporate much more phosphate than pseudo-boehmite. The IR and the NMR 27Al and 31P analysis of the adsorption products showed that when the adsorption is carried out in low concentrate phosphate solutions, the adsorbed species are surface aluminum phosphate complexes, while in samples treated with concentrated phosphate solution the products of adsorption are solid phases of aluminum phosphate. These results suggest that the incorporation of phosphate by the three aluminum hydroxides studied occur in two steps. In the first step the phosphate are adsorbed yielding surface complexes; in the second step the incorporation of phosphate occur via the process of aluminum dissolution and precipitation of an aluminum phosphate phase. The XRD analysis showed that the precipitate formed during the dissolution-precipitation process is amorphous and become crystalline after heated at 750 °C for 30 min. The slope of the zeta potential measurements of the aqueous suspensions of the adsorption products suggests that the concentration of the phosphate solution at which the transition of phosphate incorporation by adsorption changes to phosphate incorporation by dissolution-precipitation is similar for the three hydroxides (2 mmolL-1). The results showed that the incorporation of phosphate by precipitation-dissolution occur on the three hydroxides but with lower extension on pseudo-bohemite. This behavior might by related to the lower dissolution of pseudo-bohemite because it is more condensed than amorphous aluminum hydroxide and bayerite
Estudo Fitoquímico das Folhas da Espécie Psychotria prunifolia (Kunth) Steyerm (Rubiaceae)
(Universidade Federal de Goiás, 2009-07-31) FARIA, Emiret Otoni de; KATO, Lucilia; http://lattes.cnpq.br/1362891438631386
Psychotria prunifolia is a Rubiaceae family specimen found in the Goiás cerrado , which is a huge ecosystem in the Brazilian Mid-West Mainland. The NCI (National Cancer Institute) highly referred to Psychotria as a hot genera with a cytotoxic potential from its extracts and fractions. Several related chemical studies have mostly indicated findings of indole alkaloid, which are keys to various biological activities. Current ongoing studies are focusing on phytochemical investigation of P. prunifolia, and its cytotoxic, antibacterial, antioxidant, and antifungal findings from its leaves extracts and fractions. It was feasible to isolate four new indole-monoterpene alkaloids and estrictosamida upon fractioning the leaves gross extracts. Estrictosamida has been found in and isolated from other specimens from the same genera. Recently-found alkaloids have been named prunifolina, prunifoliona, EPP26.2 e EPP28.1. Indole-monoterpene alkaloid is of greater chemotaxonomic importance for the Rubiaceae family, and it may assist with better classifying heteropsychotria sub-genera specimens. In vitro analysis of four cultures of cellular kinds, (S-180- Mice Sarcoma, A549- Human-Lung Carcinoma, K562 Chronic Human Myeloid Leukemia e HFF- 1-Regular Human Cells fibroblasts), has demonstrated successful cytotoxic activity of the P. prunifolia specimen. As a result of the antibacterial analysis, the leaves extracts were deemed to be less active. Extracts of leaves have shown little efficacy with its antioxidant potential, and in vitro antifungal analysis has indicated mild or little response.
ESTUDO DE FASES E CRESCIMENTO DE MONOCRISTAIS NO SISTEMA Bi2O3 - TiO2 - ZrO2
(Universidade Federal de Goiás, 2008-08-18) FERREIRA, Katiúscia Daiane; CARVALHO, Jesiel Freitas; http://lattes.cnpq.br/5841291496427516
I n this work a systematic study on the phase formation and stability in the system Bi2O3-ZrO2 was realized, the solubility of the Zr4+ ion in Bi12TiO20 (BTO) was investigated and Zr-doped BTO crystals (BTO:Zr) were grown and optically characterized. It was verified that a tetragonal phase was formed in the following wide composition interval: (6-x)Bi2O3:(1+x)ZrO2, with x = 0.5, 0.3, 0.2, 0.1, 0, -0.1, -0.2, -0.3, -0.5, -0.65 e -0.7. The phases were synthesized by solid state reaction and the powders were characterized by Xray diffraction and diferential thermal analysis. The formed tetragonal phase, however, was metastable for all investigated compositions and its preparation was dependent on the sample thermal history. The stable phase at room temperature was a monoclinic one. A low solubility of Zr4+ in BTO was verified, but BTO:Zr single crystals were grown by Top Seeded Solution Growth (TSSG) technique. Good quality crystalline samples were prepared and characterized by chemical compositon and by optical activity, photoconductivity and electro-optical measurements. The results shown that Zr-doping produced a decreasing in the crystal photosensitivity, and almost no changes in the optical activity and electro-optical coefficient were generated.
Síntese e caracterização de complexos de platina (II) com N-benzoil-N -piridinil-guanidinas
(Universidade Federal de Goiás, 2011-08-26) FERREIRA, Rubiane Marta Mayer; SOUZA, Aparecido Ribeiro de; http://lattes.cnpq.br/7884708272070266
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Análise multiparamétrica da qualidade dos frutos, mostos e vinhos de jabuticaba
(Universidade Federal de Goiás, 2012-06-28) FORTES, Gilmara Aparecida Corrêa; SANTOS, Suzana da Costa; http://lattes.cnpq.br/7811945085200334
Chemical parameters were monitored during the jabuticaba s development, fermentation and ageing of its wine, by quantitative 1H NMR, spectrophotometric assays and standard methods of analysis. Data collected were analysed by variance (ANOVA), principal components (PCA), hierarchical cluster (HCA) and canonical correlation analyses (CCA). Jabuticaba s development was analysed in order to identify the optimal harvest period for winemaking. Total acidity decreased 70.5%, whereas reducing sugars increased about threefold in pulps up until the full ripe stage. Anthocyanin levels underwent a sharp increase in the skins reaching 22.0 mg/g at complete maturation. Tannins and total phenols showed no significant differences in their levels between ripe and full ripe stages. The PCA and HCA distinguished two sample groups, the first comprised of samples from the first four days of fermentation characterized by high levels of fructose, glucose, anthocianins and colour intensity (19.90 g/kg; 36.95 g/kg; 177.88 mg/L and 8.6). The second cluster consisted of samples from days 5 to 14 with higher levels of ethanol, glycerol, methanol, acetic acid (75.02; 3.13; 0.19 and 0.99 g/kg), hue and pH (1.25 and 3.49). The canonical correlation analysis confirmed the influence of alcohols (ethanol, methanol and glycerol), organic acids (citric, succinic and acetic acids), pH and titratable acidity on the extraction and stability of anthocyanins and copigments. Three clusters were identified by the multivariate statistical analysis of red wine samples from 2001 to 2010. Cluster I, wines from 2001, 2002, 2003 and 2006, was characterized by chemical age 1 and 3, hue (1.02; 0.89; 1.83), acetaldehyde and alcohols (0.04 and 0.24 g/L). The wines from 2005, 2007 and 2008 formed the second cluster and presented the lowest content of superior alcohols (0.14 g/L). The third cluster was comprised by wines from 2009 and 2010, which contained higher levels of methanol, acetic and latic acids (0.12; 1.24; 0.35 g/L), and the highest pH (3.96). The canonical correlation analysis revealed that chemical age 1, 2 and 3 correlate negatively with anthocyanins, pH and titratable acidity, confirming the importance of pH and acidity in the anthocyanins stability and polimerization.
Avaliação do desempenho analítico de microssistemas eletroforéticos fabricados em poliéster-toner
(Universidade Federal de Goiás, 2012-08-06) GABRIEL, Ellen Flávia Moreira; COLTRO, Wendell Karlos Tomazelli; http://lattes.cnpq.br/8302650734477213
Síntese e caracterização de peneira molecular mesoporosa mcm-41 com níquel impregnadas e in situ
(Universidade Federal de Goiás, 2008-05-14) KLEIN, Karina Vitti; NUNES, Liliane Magalhães; http://lattes.cnpq.br/6591210839894513
The new family mesoporosas molecular sieves, known as M41S, have been very studied since its discovery in 1992, with bigger prominence for MCM-41, that had its mesoporosa structure that allows ample applications in catalytic processes. In this work were studied two reactions conditions of preparation of the MCM-41 and three forms of nickel incorporation. In the synthesis of the MCM-41 the hidrotérmico treatment and in conditions was used surrounding, while in the incorporation, was used to impregnation of ions nickel and nanopartículas of nickel oxide, as well as the direct synthesis where the nickel was introduced in the structure of the MCM-41, during the synthesis. The gotten materials had been characterized by elementary nickel analysis, X-ray diffraction, nitrogen adsorption/desorption, FT-IR spectra, thermogravimetric analysis, thermoprogrammed reduction. The characterizations had indicated that it had the formation of the mesoporosa structure with periodic pore system, typical of the MCM-41, in both methods of synthesis, being able to be evidenced the biggest viability of the synthesis of the MCM-41 in the surrounding conditions. It can also be verified that it had nickel incorporation in all samples, independent of as this element was inserted. The introduced samples that had had nickel during the synthesis had presented greater excessively average diameter of pores in relation. After the characterization, the samples with nickel had been tested as in the reaction of conversion of carbon monoxide the high temperatures catalytic, known as HTS reaction, presenting activity.
Aplicações de métodos quimiométricos para classifica-ção de cigarros
(Universidade Federal de Goiás, 2009-08-13) MOURA, Monique Jesus Rodrigues; SOUZA, Paulo Sérgio de; http://lattes.cnpq.br/0834231763464061
Inorganic constituents found in cigarettes come from the tobacco plant, as it absorbs them from the soil, which can be contaminated by chemical fertilizers and environment factors. Inorganic constituents are necessary for many vital functions of human metabolism, but their lack or excess in human body can lead to biological disorder. Lead and cadmium are particularly toxic. While cobalt, cupper and nickel can be highly toxic if inhaled as carbon composites, and that is what happens as a person smokes. In this work, twenty cigarette brands, commonly available to consumers, were classified using chemometric methods, regarding the concentration of potentially toxic inorganic constituents, as Cd, Co, Cu, Pb and Ni. A method of acid digestion in microwave oven was used for opening the samples that was done in triplicate, using HNO3 65% and H2O2 35% as reagent. Flame Atomic Absorption Spectrometry (FAAS) was used as analytical technique for the five inorganic constituents determination in the cigarette brands, which results were expressed in μg g-1. Results points to Cu, Pb and Co, as the main elements in every sample. Ni is an element of intermediate content while Cd presents values under 0,6 μg g-1. PCA and HCA, Chemiometric Methods, were applied, after determination of these inorganic constituents in cigarette samples. PCA from original data in five spatial dimensions inside the three main component plane explains 83,25% of total variance, being verified the formation of four distinct classes. HCA presented the same groups formed by PCA. Therefore this research goal is to verify if popular cigarette brands are potentially toxic inorganic constituents source and to classify them as the concentration of these elements by Chemometric Methods
Composição e variabilidade enantiomérica de α-pineno em Constrictotermes cyphergaster (Silvestri, 1901) (Isoptera; Termitidae)
(Universidade Federal de Goiás, 2011-10-07) OLIVEIRA NETO, Jerônimo Raimundo de; AZEVEDO, Neucírio Ricardo de; http://lattes.cnpq.br/7186679948528167
Termites are eusocial insects of isoptera order that part in seven families. In this study we analyze the chirality of α-pinene in the defensive secretion that C. cyphergaster (Isoptera, Termitidae, Nasutitermitinae) this compound showed that among the majority of termite volatile. Along with checking the chirality was made a study seeking to correlate the production of each enantiomer, R(+)-α-pinene and S(-)-α-pinene, soil and climate data in dry and wet seasons of year 2002 and 2003. In the statistical data were used some statistical techniques such as Detrended Correspondence Analysis, to predict the model, Analysis of Variance for multiple comparison of means, and Redundancy Analysis to show a correlation matrix by another and that have a preview of the separation of groups. The DCA analysis showed that the model is linear. The analysis of variance for both the original data and for the transformed data showed that the averages do not differ statically at 95%, because they have p>0,05. The analysis of redundancy was not possible to explain the environment by the response matrix, in the 95% level of confidence. There was a production of enantiomeric α-pinene by the C. cyphergaster populations, which can be an important factor to assist in chemotaxonomic studies of these specimens. There is increased production of the (S) enantiomer, but it was not possible to correlate this trend with soil and climatic factors in statistically significant odds. The variation of the enantiomérica composition can be related to factors other than soil and climate, such as ecological factors, genetic, or eusocial.
Clube de Ciências: desenvolvendo competências brincando
(Universidade Federal de Goiás, 2009-09-10) OLIVEIRA, Adriano José de; BOTTER JÚNIOR, Wilson; lattes.cnpq.br/6176798892327803
This work uses recreational activities in the teaching of science to the development of skills in high school students in a public school network. A theoretical discussion is made with respect to recreational activities, science club, and skills and competencies. As well as describes the method used and its characterization. We have made nine Science Club activities, which were made using texts and discussions, card game, another text to discussion, class exhibition of two teachers using experimentation, use of magazines - Veja, Isto é, Época, Tititi e Química Nova na Escola - for the learning of science, delivery of a text for discussion, two activities to form a chemical jury and finally the theatrical game - Chlorine Chemistry Jury. These applications within the science club proved to be an alternative for the development of the field of competence, due to almost 100% of our participants have acquired the skills and competencies desired. Finally, it is concluded that the teacher should always innovate and try to qualify.
SÍNTESE DE POLI (ÁCIDO LÁTICO-CO-ÁCIDO GLICÓLICO) ATRAVÉS DE POLICONDENSAÇÃO CATALISADA POR RESINA DE TROCA IÔNICA CONTENDO ÓXIDO DE ESTANHO COMO CO-CATALISADOR.
(Universidade Federal de Goiás, 2008-11-27) OLIVEIRA, Leonardo François de; RABELO, Denilson; http://lattes.cnpq.br/4961539278604455
In this study PLGA copolymers were synthesized with molecular weight above 10 kDa through direct polycondensation of L-lactic acid and glycolic acid monomers. Catalysts based on sulfonated styrenedivinylbenzene copolymer (SC) containing or not Sn2+ íons adsorbed as SnCl2.H2O colloidal particles from neutral solution or [SnCl3]- complex anions from acid solution were prepared. All catalysts were evaluated by specific surface area and pore volume measurements, infrared spectroscopy, X-ray diffraction, atomic absorption spectrophotometry and ion exchange capacity. The obtained PLGA copolymers were characterized by infrared spectroscopy, X-ray diffraction and inherent viscosity measurements. Independent of pH solution of the adsorptions, it was observed that Sn2+ ions were oxidized to Sn4+ forming SnO2. This oxidation probably occurred during catalysts drying process in the presence of oxygen. The PLGA copolymers with highest inherent viscosities, i.e., highest molecular weights were obtained with SC catalyst containing SnO2 prepared by adsorption of SnCl2.H2O colloidal particles in neutral solution. It was estimated that the highest PLGA molecular weights were equal or larger than 35 kDa. The produced PLGA presented white or lightly yellow color and Sn contamination less than 1 ppm which is below the limit allowed by the Brazilian legislation
Contribuição ao estudo de espécies da familia Rubiacvea: Fitoquímica da espécie Amuaioua guianensis Aulb
(Universidade Federal de Goiás, 2009-06-05) OLIVEIRA, Pollyanna Laurindo de; OLIVEIRA, Cecilia Maria Alves de; http://lattes.cnpq.br/3152041311943092
Amaioua guianensis Aulb is a shurb best known as marmelada-brava or marmelinho-vermelho belonging to Rubiaceae family. Amaioua genus comprise 10 species which are distributed through Floresta Amazônica, Cerrado, Pantanal and Mata Atlântica. No phytochemical work has been reported on the leaves and bark of A. guianensis. As part of our ongoing search for new compounds from higher plants we undertaken and investigation of the ethanolic extract of A. guianensis as well as their antioxidant na molluscicidal activity. In this study we describe the isolation and structural elucidacion of a new conpound, a cyclopeptide (2), and twelve known compounds: a coumarin (1), two pentacyclic triterpene (3 and 4), mannitol (5), ethylglucose (6), three chorogenic acids (7, 8 and 9), two proanthocyanidins (10 and 11) and two steroids (12 and 13). The crude ethanolic extract, its purified fractions soluble in n-hexane, ethylacetate and methanolic, besides compounds 10 and 11 promptly reacted with DPPH leading to a loss of 50% in the absorbance activity in the concentrations of 78, 25, 246 and 4 μg/mL, respectively. The results of the molluscicidal assays with the crude ethanolic extract and its fractions indicated that ethylacetate fractions is the most active fraction with LC100 100 ppm and LC50 42,5 ppm

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