Mestrado em Química - PPGQ

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    Síntese de óxido de silício a partir do bagaço da cana-de-açúcar modificado com óxido de ferro magnético: aplicação em fotodegradação do corante amarelo de tartrazina
    (Universidade Federal de Goiás, 2021-06-30) Tateno, Nathalia Sayuri; Martins, Marccus Victor Almeida;;; Oliveira, Jocélia Pereira de Carvalho;;; Oliveira, Jocélia Pereira de Carvalho; Ramirez, Fabian Enrique Nima; Godinho Júnior, Mário
    The development of technologies that can reuse this biomass for the benefit of the environment becomes an inherently necessary strategy. Within this context, this work used sugarcane bagasse for the production of silica. This silica was modified with magnetite nanoparticles (since it can be magnetically recoverable, preventing the effluent from having more residue) to be applied as photocatalysts for the degradation reaction of tartrazine yellow dye used as model dye. Morphologically, SiO2 was show porous and has a predominantly quartz structure. Spectroscopically, silica was confirmed due to the absence of vibrational modes of organic chromophores. From the synthesis of magnetic nanoparticles through the co-precipitation method in the presence of silica, a core-shell system (SiO2@Fe3O4) was obtained, which was confirmed by X-ray Diffraction and Scanning Electron Microscopy. The low value calculated for the band gap energy for SiO2@Fe3O4, by the Tauc method, indicated a facilitation in the photodegradation of the dye due to the presence of a heterojunction of the SiO2@Fe3O4 system. Finally, the degradation efficiency of tartrazine yellow dye was more than double when compared to the action only of silica.
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    Estudo da interação entre a enzima tripsina e nanopartículas de prata
    (Universidade Federal de Goiás, 2021-04-30) Siqueira, José Guilherme Martins; Oliveira, Jocélia Pereira de Carvalho;;; Oliveira, Jocélia Pereira de Carvalho; Silva, Welter Cantanhêde da; Sousa, Lorena Ramos Freitas de
    The study on interactions between biomolecules and nanomaterials is a chemistry/nanoscience interface that emerges to understand the behavior of materials in relation of several biomolecules, since this materials interact with biologic fluids, the study of how these nanomaterials and biomolecules interactions happen became an important task. Enzymes play a fundamental role in metabolism and their imbalance can lead to the onset or worsening of diseases. The enzyme trypsin is the most used enzyme for over five decades due to its physiological importance, as it participates in the digestive process, blood clotting and fertilization. In this context, this work aimed to study how the interaction between the enzyme trypsin and silver nanoparticles occurs in aqueous medium. Silver nanoparticles were synthesized using the chemical co-reduction method, which presented the plasmatic band with maximum absorption at 407 nm, after the addition of trypsin for adsorption, which caused a shift to the color red. Through spectroscopy in the infrared region, the presence of the main vibrational modes can be confirmed before and after the formation of the nanobiocomposite. Morphologically, the synthesized nanoparticles had a spherical shape. Other studies revealed that, after the interaction, there is a zeta potential decrease and a consequent increase in the hydrodynamic radius, these changes in the characteristics affected the secondary structure of the protein, causing loss of organization and formation of a more hydrophobic nanoparticleenzyme complex, due to the interactions electrostatic and hydrogen bonding
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    Desenvolvimento de método adaptado de extração com ponteiras descartáveis para determinação de íons Pb(II) e Mn(II) utilizando taboa (Typha angustifólia L.) como adsorvente
    (Universidade Federal de Goiás, 2020-12-18) Ferreira, Marina Mesquita; Alves, Vanessa Nunes;; Alves, Vanessa Nunes; Lemos, Valfredo Azevedo; Freitas, Sílvia de Sousa
    In this work, the extraction technique with disposable tips (DPX - from English disposable pipette extraction) was used using Typha angustifolia L. (cattail) as an adsorbent. An adapted DPX method was developed for the determination of Pb(II) and Mn(II) ions in aqueous samples, using the Flame Atomic Absorption Spectrometry (FAAS) technique for quantification. The characterization of the cattail was performed through X-Ray Diffraction, Infrared Spectroscopy, X-Ray Fluorescence Spectroscopy, Determination of the pH at the Zero Charge Point and Buoyancy, with results consistent with those observed in the literature. The zero load point of the material was determined at 6.39. The pH of the solution was univariate optimized by selecting the solutions of Pb(II) and Mn(II) ions at a concentration of 1.0 mg L-1 at pH 8. Tests to optimize the parameters that influence the adsorption and desorption of the ions were made in a multivariate manner. Through Doehlert planning, it was possible to obtain optimal values for mass of adsorbent and number of adsorption cycles, being defined in 30 mg and 7 cycles, respectively, for Pb(II) and Mn(II) ions and the concentration of HNO3 and number of desorption cycles, in 0.8 mol L-1 and 7 cycles. The kinetic study indicated that the adsorption of the Pb(II) and Mn(II) ions obey a pseudo-first order and Avrami kinetics, respectively. The maximum adsorption capacity was obtained through the construction of adsorption isotherms, with values of 29.17 and 5.64 mg g-1 being found for the Pb(II) and Mn(II) ions, respectively. Under optimized conditions the extraction method presented detection limits of 17.51 μg L-1 (Pb (II)) and 35.02 μg L-1 (Mn (II)), quantification limits of 58.37 μg L-1 (Pb (II)) and 116.7 μg L-1 (Mn (II)), and a pre-concentration factor of 10 (Pb (II)) and 2 (Mn (II)), being a linear range of 116.7 to 2000 μg L-1 method for Mn (II) and from 58.37 to 2500 μg L-1 for Pb (II). Accuracy was evaluated separately in terms of repeatability and reproducibility, obtaining D.P.R. values of 0.31 and 0.25% for Pb (II), respectively, and 7.00 and 9.88% for Mn (II), respectively. The evaluation was evaluated by means of recovery tests in river water collected near a mining company, recovery values in the range of 80-120% and through the use of certified reference materials, indicating high reliability of the method.
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    Estudo teórico, síntese e caracterização de novos ligantes imínicos coordenados a metais de transição como possíveis constituintes para dispositivos eletrônicos
    (Universidade Federal de Goiás, 2020-07-31) Kunizaki, Fernanda Cristina da Costa; Romualdo, Lincoln Lucilio;;; Romualdo, Lincoln Lucilio; Gurgel, Maria Fernanda do Carmo; Patrocínio, Antônio Otávio de Toledo
    Nonlinear optics, which is dedicated to the study of the interaction of light with matter, has driven, over the past few years, the search for materials that present the generation of the second harmonic, a phenomenon known as hyperpolarisability. There are some molecular characteristics that can increase the non-linear optical response of the compounds, such as: -conjugated system, dipole moment, planar structure, etc. One way to achieve the necessary properties in a new compound, optimizing experimental procedures, is the use of computational calculations, which help the structural optimization of the compound and quantify values for non-linear optical responses. Starting from the DFT, using the functional CAM-B3LYP and the bases 6-311+G and LANL2DZ, the imine ligands were optimized, with substituting donor and acceptor groups of electronic density. With the intention of evaluating the performance of coordination compounds, metal ions from the first and second series of transition have been proposed using the iminic ligands already optimized. Among the compounds that were optimized, it with the highest non-linear optical response was the one with the Mn2+ ion. The manganese complex showed a hyperpolarizability value of 1.73x10-26 e.s.u. Based on the computational study, a synthetic route for the ligands and complex was established, reaching yellow solids with melting point above 212 °C to complex. FTIR and UV/Vis characterizations were compared to theoretical data. In the FTIR, the disappearance of N-H (3400 cm-1) absorptions, characteristic of amines and the formation of iminic ligands by the formation of the C=N bond (1635 cm-1), disappeared. Based on the theoretical results and the success in the synthesis of the target compound, it may be a candidate for experimental studies in the area of non-linear optics.
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    Triagem in vitro de produtos naturais e derivados sintéticos em busca de inibidores de urease
    (Universidade Federal de Goiás, 2020-11-27) Rosa, Tainara da Fonseca; Sousa, Lorena Ramos Freitas de;; Pérez, Caridad Noda; Severino, Richele Priscila; Sousa, Lorena Ramos Freitas de
    Helicobacter pylori is a bacteria living in the stomach and it’s associated with several diseases in the gastrointestinal system. The survival and replication of H. pylori is related to the enzymatic activity of urease, which allow the resistance of bacteria to gastric acidity. Antimicrobial drugs are used against H. pylori, but there are occurrence of antibiotic resistance. In the view of the need for new antibacterial agents, this study aimed to investigate new compounds, of natural and synthetic source against urease. In vitro screening of compounds and Natural Products (NPs) was performed using the spectrophotometric method by measuring the reaction product (indophenol blue) at λ = 600 nm. The enzyme kinetics study of urease (Canavalia gladiata) (UJB) was performed for assay standard and the Km, Vmax and Kcat data (4.25 ± 0.62 mmol/L, 44.34 ± 1.33 mmol/L/min and 2062.3 s-1, respectively) were found similar to literature. Among the 37 chalcones assessed, nine showed significant inhibition (1a, 1c, 1g, 1h, 2a, 2b, 2c, 2d and 2m) with inhibitory potency ranging between IC50 = 5.7 and 18.8 µmol/L. The inhibition mechanism was determined for the most potent compounds by in vitro and in silico assays, which chalcones 1h (Ki = 2.98 µmol/L), 2a (Ki = 6.19 µmol/L), 2c (Ki = 1.87 µmol/L), and 2m (Ki = 3.13 µmol/L) showed competitive behavior and 1c non-competitive (Ki = 17.3 µmol/L). Chalcones 2c and 2m revealed the best MIC values (250 and 128 µg/mL, respectively) anti-H. pylori in vitro. Among NPs evaluated, five compounds from the fungus Fusarium proliferatum (5a-5e) were also inhibitors of UJB, which compounds 5a and 5b showed lower IC50 values with competitive behavior on urease (Ki of 0.55 and 1.1 µmol/L). Crystals obtained from the active extract of Pholiota nameko mushroom were analysed by 1D and 2D NMR experiments, and the compound was characterized as mannitol, which showed an IC50 value of 35.5 µmol/L on UJB. The inhibitory enzymatic activity by mannitol could be a clue for the gastroprotective action and anti-H. pylori potential found in previous work. By in silico screening, the pharmacokinetic properties of all compounds were investigated using Lipinski's Rule of Five (RO5) as the main parameter. In addition to bioavailability study of these compounds, it was possible to use the obtained results to understand better the chalcones behavior (2c and 2m) revealed on H. pylori in vitro assay. By using in vitro and in silico tests it was possible to find new and promising UJB inhibitors.
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    Prospecção química e avaliação leishmanicida das flores de Pterodon pubescens
    (Universidade Federal de Goiás, 2020-10-23) Ribeiro, Alline de Matos; Gomes, Adriane da Silveira;; Sousa, Lorena Ramos Freitas de;; Sousa, Lorena Ramos Freitas de; Ramalho, Suelem Demuner; Carbonero, Elaine Rosechrer; Gomes, Adriane da Silveira
    The species Pterodon pubescens (Fabaceae) is a plant known as “sucupira-branca” and its leaves and fruits are used in folk medicine to treat respiratory diseases. In previous works, chemical investigations of the leaves of this species allowed the identification of sesquiterpenes, flavonoids, steroids and diterpenes and also revealed potential leishmanicidal activity. Leishmaniasis is an infectious disease that affects millions of people worldwide and the drugs that are used in the treatment have several side effects, high toxicity and parasitic resistance. Bearing in mind that there are no studies of P. pubescens flowers and the importance of identifying new leishmanicidal agents, this work aimed to contribute to the chemical and biological knowledge of this species. The chemical profile of P. pubescens flowers was determined using hyphenated analytical techniques of UPLC-ESI-QqTOF-EM / EM and GC-MS, and 1H NMR spectroscopy, confirming the presence of secondary metabolites from the flavonoid and terpene classes. The study of the ethyl acetate fraction led to the isolation of the phenolic compound ethyl gallate (I), which originated from the acetylation of gallic acid. From the ethanolic extract and the ethyl acetate (EPpEA), hexane (EPpEH) and hydroalcoholic (EPpEHi) fractions of P. pubescens flowers it was possible to identify six flavonoids, a sesquiterpene and a diterpene by UPLC-ESI QqTOF-MS/MS and by GC-MS it was possible to identify thirteen sequiterpenes. In particular, in vitro screenings were carried out on the parasite and Leishmania amazonensis arginase (ARG), an enzyme involved in the parasite's life cycle using the ethanolic extract and the EPpEA, EPpEH and EPpEHi fractions. The evaluation of the ethanolic extract and fractions against the L. amazonensis ARG enzyme showed an inhibition rate between 67% and 82%. In the active fractions EPpEA and EPpEHi several flavonoids (gallic acid, quercetin-O-dihexoside, quercetin-O-hexoside, flavan-3-ol, quercetin, luteolin and kaempferol) and were identified that may be related to the inhibitory activities found, as they are described in the literature as inhibitors of ARG. In the evaluation against the Leishmania infantum protozoan, the extracts and fractions did not significantly inhibit the parasite. The results obtained are relevant for the knowledge of the studied species, which until now, within our knowledge, there has been no study of white sucupira flowers.
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    Avaliação da produção de metano no biogás frente a diferentes diluições do dejeto bovino e a influência nutricional
    (Universidade Federal de Goiás, 2020-07-20) Assunção, Geiza Pereira de; Figueiredo, Alberthmeiry Teixeira de;; Sarmento, Antorver Panazzolo; Barrado, Cristiano Morita; Figueiredo, Alberthmeiry Teixeira de
    The effluent resulting from the confinement of ruminant animals, specifically dairy cows, exhibits a high concentration of organic matter and contaminating agents that pose a threat to the environment as a result of their improper handling. One of the solutions found to treat and minimize the amount of these residues and, consequently, the pollutants produced is to use the residual organic matter as a sustainable energy source. An example is the use of the waste of these animals as a source of energy, both thermal and electrical, through the production and use of biogas. Thus, the main object of study of this work was to evaluate the effect of anaerobic biodegradability of bovine manure in controlled conditions of temperature and agitation, testing different dilution factors, linked to the diet of dairy cows for the improvement of methane production, in scale laboratory by batch system. The work is divided into two stages. The first was the optimization of the dilution in the efficiency of methane production, where the sample of crude manure (without diluting) was studied in addition to the dilutions 1:2; 1:6 and 1:10 (manure / water) and the influence of animal nutrition as a second stage. The biodigesters were evaluated from the efficiency of removal of organic matter (O.M.) in the physical-chemical analyzes of COD, BOD, and TVS, and in the productivity of methane. It was found that the most diluted reactors were the conditions that showed the best results of O.M. removal both in the form of COD and BOD, however, the same behavior for methane production was not observed, since the higher methane production was directly proportional to the content of incubated organic load, that is, the reactors supplied with higher concentrations of bovine manure (lower% water) exhibited higher yields. With the aid of the modified Gompertz mathematical model, he verified that the excess of O.M., due to the non-dilution of bovine manure (R.1), results in long periods of adaptation of the microorganisms (lag phase), that is, a delay in production, about two months for effective start in methane production. In the second stage, it was concluded that animal feed supplementation directly influences the production of ideal residues (rich in energy and nutrients) for the biodigestion process, since the reactor (G.3) supplied with waste from the group of animals fed with greater nutritional highest load exhibited the highest methane production, about 107% more than the reactor supplied with group 1 residues lowest nutritional charge.
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    Síntese e caracterização de nanocompósitos ocos de Y2O3:Eu3+ revestidos com Fe3O4
    (Universidade Federal de Goiás, 2020-07-24) Caldas, Maylura Morais; Figueiredo, Alberthmeiry Teixeira de;; Figueiredo, Alberthmeiry Teixeira de; Tranquilin, Ricardo Luís; Barrado, Cristiano Morita
    The study of hollow structures has stood out for being considered functional materials and due to their properties such as high load capacity, low density and high surface area. This set of factors allows the hollow structures to gain space in research for the production of new materials. Combined with these factors, luminescent and magnetic properties in a single material have been explored for their ability to track and visualize. Among the materials with luminescent properties, Y2O3:Eu3+ is highlighted as an important luminophore with red emission, easy to produce and with good stability. Among the magnetic materials, Fe3O4 stands out due to its compatibility with biological systems and its superparamagnetic behavior. In the present study, the synthesis and structural and morphological characterization for the production of hollow double hull spheres Y2O3:Eu3+@Fe3O4 was verified. To obtain these hollow structures of spherical morphology, the hard templating method was used, using carbon spheres obtained by the hydrothermal method, as a hard templating. The coprecipitation synthesis was used to coat the carbon spheres with Y2O3:Eu3+ and Fe3O4, and the resulting materials were subjected to heat treatment to remove carbon. The composites obtained have spherical and hollow morphology, based on the micrographs obtained by scanning electron microscopy with field emission (FEG), according to the X-ray diffraction, the structures were crystalline and presented phases related to Y2O3 and Fe3O4. The crystallite sizes were calculated providing evidence that Y2O3:Eu3+ and Fe3O4 nanoparticles covered the rigid model. The luminescent and magnetic properties were investigated and their results show compliance, the luminescent emissions characteristic of the Eu3+ ion in the 612nm region corresponding to the orange/red emission of the electromagnetic spectrum and superparamagnetic character due to the magnetic characteristics of Fe3O4.
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    Estudo da interação da enzima tripsina com nanopartículas de ouro
    (Universidade Federal de Goiás, 2020-07-03) Santos, Leidiane Almeida; Martins, Marccus Victor Almeida;; Oliveira, Jocélia Pereira de Carvalho;; Oliveira, Jocélia Pereira de Carvalho; Braga, Elaine Alves de Faria; Gurgel, Maria Fernanda do Carmo
    Proteases are one of the largest groups of enzymes and have several applications ranging from food processes to pharmaceuticals. Within this group, Trypsin, a serine protease excreted by the pancreas as an inactive, proenzyme (trypsinogen), is present in the digestive systems of vertebrates and invertebrates. As protease is one of the most abundant classes of enzymes, there are several studies on its physiological importance. Some studies show, for example, the significant role of the interaction of nanomaterials with enzymatic biomolecules, such as proteases. In comparison with small molecules, nanoscale structures express several physical and chemical properties, which can be associated with biomolecules in order to enhance their functions. One of the most used nanomaterials are gold nanoparticles (NpAu), which are produced for various applications, for example, in therapeutics, detection and diagnosis, chemical and biological sensing and catalysis fields. Within this context, this work reports two routes of synthesis of gold nanoparticles associated with the enzyme Trypsin. The synthesis methodology was based on the traditional Turkevich method followed by adaptations. The results showed that the two methodologies were efficient, generating the expected biconjugate systems, as can be proved by the spectroscopy analyzes in the UV-Vis region. The infrared (FTIR) confirmed the interactions between the enzyme and the surface of the gold nanoparticle. Morphologically, the images obtained by scanning electron microscopy (SEM) transmission (TEM) showed nanoparticles spherical and without agglomerations. The gold nanoparticle and trypsin biosystem proved to be stable over the 30-day period. This biosystem is promising for the understanding of future applications that involve the interaction process between the enzyme and its respective substrate.
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    Investigação fotocatalítica das heteroestruturas BIVO4/CoFe2O4 no corante azul de metileno
    (Universidade Federal de Goiás, 2020-07-22) Oliveira, Leticia Guimarães; Godinho Junior, Mario;; Godinho Junior, Mário; Silva Junior, Domingos Lopes da; Gurgel, Maria Fernanda do Carmo
    Materials such as: BiVO4 and CoFe2O4 are of great importance because they have unique characteristics and properties. BiVO4 can be applied in catalysis, photoluminescence, partition, among others. CoFe2O4 is a magnetic material and a photocatalyst used in Fenton and Foto-Fenton reactions. In this work, BiVO4 and CoFe2O4 powders were synthesized in their pure form by coprecipitation with subsequent microwave-assisted hydrothermal treatment (CPTHAM), at 130 ° C for 30 min, with a heating rate of 10 ° C / min. Heterostructures composed of materials, BiVO4 and CoFe2O4 were displaced with proportions of 1 and 2 mol of BiVO4 to 1 mol of CoFe2O4 using CPTHAM. CoFe2O4 prey were anterior with spinel-type monophasic cubic phase and for BiVO4 they were eliminated as monoclinic and tetragonal phases. In the structural characterization by X-ray diffraction (XRD) of the heterostructures, all phases of interest were observed. The band gap values of the materials were determined by diffuse reflectance using UV-Vis spectroscopy. The values of the gap band were 2.41 for BiVO4 and 1.75 for CoFe2O4, respectively. The investigations of the photocatalytic and magnetic properties, observed a discoloration of the methylene blue dye of 60% and 58% in 120 min using a BiVO4 / CoFe2O4 heterostructure in the proportions of 1: 1 and 2: 1. It was noted that in the attraction heterostructures per magnet was efficient. In this way, the results obtained demonstrate that the heterostructures are effective in discoloration of the methylene blue dye and that they can be recovered after using a magnetic field.
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    Os elementos terras raras na indústria de fertilizantes fosfatados do complexo carbonatítico Catalão I - GO: potencialidades de recuperação
    (Universidade Federal de Goiás, 2019-07-05) Franzoi, Isthar Sofia; Zamunér Filho, Antonio Nilson;; Romualdo, Lincoln Lucíolo;; Figueiredo, Alberthmeiry Teixeira de; Sousa, Marcelo Henrique
    Phosphatic rocks are the greatest phosphorus source in agriculture. Due to the geologic origin of some of them, they are known for having Rare Earth Elements (REE). The goals of this study were: to quatify the REE in the local phosphate fertilizers production chain; to select targets that enables the REE recovery; to perform the physicochemical characterization of chosen samples and to try out rare earth recovery approaches. Sampling was carried out in the industrial facities from Ouvidor and Catalão. In total, 19 samples were collected in several processing stages and the numerical results pointed out the presence of REE both in the raw material and in the end product, even as all points. The most plentiful metal was Cerium (2.149,3 – 9.964,0 mg L-1), followed by Lanthanum, Neodymium and Praseodymium. The granulometric distribution proved the relation between the REE preconcentration in the productive process and fines percentage in the sample. Four samples were selected for a physicochemical characterization. Tests of leaching and solvente extraction were held in a tailing and in a concentrate. The tailings leaching tests have reached light REE extractions in the order of 79% in chloride environment and 69% in sulphuric environment. Afterwards in the extraction by solvente using tributil phosphate (TBP), iron has been successfully removed from liquor in chloride environment while in sulphuric environment there was not significant separation. In the concentrate sample, the leaching was carried out according to the prodution model of phosphoric acid, therefore, two routes were considered, the hydrochloric and sulphuric one. When it comes to P2O5 solubilization both have been sucessful reaching about 90%. The sulphuric route has showed the advantage of an acid liquor with a low calcium concentration by the phosphogypsum precipitation. Although it ocurred the partitioning of the REE between phosphogypsum and acid solution that after makes the rare earths recovery more dificult. The shown disadvantage by the hydrochloric acid route was the high calcium levels in the acid solution. However, all the solubilized REE have stayed in the solution, which facilitates the subsequent separation steps. Phosphorus extractions with TBP in chloride environment (36-38%) were higher than those achieved in the sulphate environment (8-9%). This job shows options of recovery of high economic and technological use elements, in order to provide advances in the sustainability of the phosphate fertilizer industry processes.
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    Deposição de filmes finos de TiO2 em superfície de vidro e avaliação das suas propriedades fotocatalíticas
    (Universidade Federal de Goiás, 2019-07-03) Gonçalves, Elizael de Jesus; Barrado, Cristiano Morita;; Barrado, Cristiano Morita; Figueiredo, Alberthmeiry Teixeira de; Martins, Marccus Victor Almeida
    Water is one of the most abundant and most important available resources for life's existence and permanence. The National Water Agency reports that there is an increasingly inversely proportional relationship between demand and the availability of freshwater, it makes necessary to reuse this natural resource so that the world population does not enter into water chaos. Thus, the main problems encountered are the population increase and the intensification of industrial activities, which contributes to the generation of possible outbreaks of water resources contamination. However, the treatment performed by the ETAs and ETEs are not prepared to remove these compounds, which are largely toxic and difficult to degradation. Thus, advanced oxidative processes (POAs) are alternative technologies that are under strong interest in the scientific environment due to the high potential of removing these recalcitrant components. Among the POAs stands out the heterogeneous photocatalysis, which consists of photoactivating an inorganic semiconductor, such as TiO2, with consequent generation of highly oxidisant species. Titanium oxide (TiO2) has three crystallographic forms, being, anatase, rutile and Brokita. The synthesis method is highly determinant in obtaining these types of structure and, consequently, in the property of oxide. This work aimed to obtain titanium dioxide in the form of films using the Peroxo-Titanium complex Method (CPT), moreover, evaluating the calcination temperature, successive layers and addition of P25 in the films, and influence on the photochemical efficiency of Discoloration of the Tartrazine organic dye. The precursor gel was obtained by solubilization of titanium isopropoxide in H2O2 28% in ice bath. The TiO2 films were deposited by manual immersion, silk screen and with the aid of a brush on the glass plate of 20x76mm previously cleaned with piranha solution (H2SO4: H2O2) ratio in mol of 4:1. The films were thermally treated at temperatures of 450 º C and 550 º C for 1h30min. The resulting material was structurally characterized in the XW, morphologically in SEM and the composition was verified in the EDX. Heterogeneous photocatalysis assays were performed, exposing the tartrazine solution to the radiation of the mercury lamp and sunlight, in the time of 120 minutes and 390 minutes. In general, the formation of biphasic materials with photocatalytic activity was observed; The photocatalytic film that presented the best photocatalytic performance was the T3 material with 30% addition of P25 for promoting the total discoloration of the dye in 100%, with kap of 0.0693, it can be emphasized that the films have catalytic activity both in Presence in artificial and natural ultraviolet light; and have not shown to be toxic, with a small mortality rate Artemia salina less than 30%. The efficiency was related to the presence of a mixture of anatase/rutile phases similar to P25, which generates an effect of heterojunction increasing the photochemical efficiency to promote oxidative reactions and adsorption, favoring the discoloration of the organic compost resistant, and bringing advantages of TiO2 films, such as the reuse of glass spheres in various catalytic processes without the loss of photochemical efficiency, and the ease of removal of the material at the end of the photocatalytic process.
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    Desenvolvimento de um método de extração em fase sólida in situ para determinação de Cr(III) em infusão de fitoterápicos
    (Universidade Federal de Goiás, 2019-08-08) Siqueira, Alêssa Gomes; Costa, Bruno Elias dos Santos;; Alves, Vanessa Nunes;; Rezende, Hélen Cristine; Coelho, Luciana Melo; Alves, Vanessa Nunes; Costa, Bruno Elias dos Santos
    This work presents the development of an in situ solid phase extraction method (SPE-ISS) for the determination of chromium (III) in herbal infusion samples using flame atomic absorption spectrometry (F AAS). Thus, in order to evaluate the inorganic composition of medicinal plant samples (calendula, chamomile, carqueja, green tea, leather hat, melissa and passiflora) we used the EDXRF (Dispersive Energy X-ray Fluorescence). the presence of plant essential metals in addition to toxic metals. Subsequently, a quantitative analysis of some metal ions was performed in infusion samples prepared from these plants, and Fe(III) was the only one found in considerable concentration, while Pb(II), Cr(III), and Cd(II) presented concentrations below the detection limit of the technique. Therefore, it is necessary to develop extraction and preconcentration methods that allow the determination of Cr(III) simply and safely, even when present in low concentrations. In this work, the SPE-ISS method was optimized by multivariate techniques, and the results showed that the formation of the Cr-PAN complex is favored at pH 9.5, with the complexant at 0.18 mmol L-1 concentration. For optimization of solid phase formation and extraction, factorial design and response surfaces were used, which pointed to the use of CTAB as phase transfer agent, NaClO4 0.26 mol L-1 as ionic pairer and agitation time of 7.5 minutes. Studies of possible interferents indicated negative interference of the metallic ions Al(III), Zn(II), Fe(III) and Ca(II). The analytical performance was evaluated by the parameters, preconcentration factor, detection limit (LD) and limit of quantification (LQ) and the values ​​found were 1.66 μg L-1 and 5,5 μg L-1, respectively. The intra-day and inter-day precision (RPD) was 0.001% and 0.0004%, respectively, being the linear range of the method from 250 to 5000 μg L-1, presenting the potential to determine low chromium concentrations. Finally, the accuracy of the method was evaluated from analysis of certified reference water material (APS-1071), as well as recovery tests on water samples and herbal infusions 77.60 - 116%.
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    Conjugação das técnicas de coagulação química (Moringa oleífera) e eletroquímica (DDB) no tratamento de efluente real de indústria de tintas
    (Universidade Federal de Goiás, 2018-03-15) Barbosa, Andreia Daniane; Andrade, Leonardo Santos;; Andrade, Leonardo Santos; Sarmento, Antover Panazzolo; Barrado, Cristiano Morita
    Treatment of a real paint industry wastewater using a natural chemical coagulant based on Moringa oleifera (MO) seeds associated with Ca 2+ salts (nitrate or chloride) in order to potentiate its coagulating effect. This method of treatment was combined with the electrochemical technique from the use of a boron doped diamond electrode in a flow reactor. The main purpose of the treatments investigated was to evaluate the possibility of reuse of treated water in the production of a new paint. The treatment of the residue was evaluated by its turbidity, DFZ (color), total solids content, chemical oxygen demand (COD), biotoxicity and microbiological tests. The optimum conditions for coagulation were obtained at pH 6.5 and with coagulant dosage (50 g/L of MO) of 80 mL for each 1.0 L of residue (80 mL/L). The optimum concentration of Ca 2+ incorporated into the coagulant was 0.125 mol/L. The viability of the treatment, evidenced by the reuse of the treated water for the production of a new paint (made by the company supplying the waste), showed compatible quality with the water used by the company (tap water) only when the treatment was carried out using MO aqueous extract in association with Ca(NO 3 ) 2 salt. For the electrochemical treatment, the limit current density of (35 mA/cm 2 ) and an electrolysis time of 90 min were used. Bio-toxicity assays (A. Salina) showed that the mortality of micro crustaceans was reduced from 100% (raw effluent) to only 11% and that 85% of the effluent organic load was eliminated at the end of the electrolysis process. In addition, microbiological assays showed that the amount of mesophiles decreased by more than six orders of magnitude and no thermotolerant coliform colony was formed.
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    Síntese, caracterização e investigação da propriedade luminescente do ZnO e do ZrO 2 dopados com európio e suas aplicações na ciência forense
    (Universidade Federal de Goiás, 2018-09-28) Bernardes, Yasmim Rafaella Caixeta Pinto; Figueiredo, Alberthmeiry Teixeira de;; Figueiredo, Alberthmeiry Teixeira de; Sousa, Marcelo Henrique; Barrado, Cristiano Morita
    Recently, luminescent materials have aroused interest in the scientific and expert community due to their unique properties. These luminescent materials are being used in the production of papillary developers with excellent advantages over the commonly employed methods. These materials are based on inorganic matrices doped with TR 3+ ions. In the present work, zinc oxide (ZnO) and zirconium dioxide (ZrO 2 ) matrices with different concentrations of the earth-rare ion europium (III) were synthesized for the development of fingerprints. The materials were obtained by the sol-gel process and characterized by X-ray diffraction, photoluminescence and scanning electron microscopy to evaluate the structural properties. The XRD results showed ZnO hexagonal and ZrO 2 with different tetragonal and monoclinic phase compositions. The photoluminescent results indicated that the percentage of europium directly influences the optical properties of the synthesized materials. The synthesized materials revealed the fingerprint with clear contours that enable identification. The microscopic magnification allows visualizing the adherence of the materials by the residues of the fingerprints. Finally, the luminescent processes of Eu 3+ doped in different matrices provide the widening of the range of papillary developers. The results found contribute to the development of new materials for the development of fingerprints.
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    Micro extração em fase sólida dispersiva utilizando hematita como adsorvente para determinação de cromo em etanol combustível
    (Universidade Federal de Goiás, 2019-02-21) Oliveira, Jordana de Assis Nunes; Alves, Vanessa Nunes;; Alves, Vanessa Nunes; Tarley, César Ricardo Teixeira; Freitas, Sílvia de Sousa
    A micro extração em fase sólida dispersiva é um tipo de extração em fase sólida que possui uma série de aplicações analíticas. Assim, neste trabalho é apresentado o desenvolvimento de um método de micro extração em fase sólida dispersiva utilizando nanopartículas de hematita como adsorvente para determinação de íons Cr(III) em amostras de etanol combustível, com detecção por espectrometria de absorção atômica com atomização por chama. A hematita foi sintetizada pelo método sol-gel e caracterizada por Difração de Raios X, Espectroscopia de Infravermelho, Espectroscopia de Energia de Fluorescência de Raios X, Microscopia Eletrônica de Varredura com Fonte de Emissão de Campo, Microscopia Eletrônica de Transmissão, Magnetização edeterminação do Potencial Zeta. O material sintetizado apresentou estrutura cristalina e fase única no difratograma de raios X, sendo condizente com a ficha cristalográfica comparada. As microscopias mostraram nanopartículas com morfologia de nano-ginger, apresentando crescimento em rede ramificada, com crescimento em diferentes planos. Através do potencial zeta, foi determinado o pH no ponto de carga zero do material em 4,49. Os parâmetros que influenciam na extração do íon Cr(III) foram selecionados e otimizados. O pH da solução foi otimizado pelo método univariado, sendo obtidas as melhores extrações para uma solução contendo o íon cromo na concentração de 0,5 mg L -1 em pH 9. As demais variáveis foram otimizadas pelo método multivariado. Inicialmente um planejamento fatorial 2 4 foi utilizado para avaliar as variáveis: massa do adsorvente, tempo de adsorção e dessorção e concentração do eluente (HNO 3 ). A massa do adsorvente não foi considerada significativa e, portanto, fixada em 3,0 mg. As demais variáveis foram consideradas significativas, e otimizadas através de um planejamento composto central, sendo seus melhores valores otimizados em 112,2 s, 81,5 s e 1,0 mol L -1 para tempo de adsorção, tempo de dessorção e concentração do eluente, respectivamente. O estudo cinético revelou que a adsorção obedece a uma cinética de pseudo-pimeira ordem. A capacidade máxima de adsorção foi obtida pela construção de isotermas de adsorção, sendo encontrado um valor de 38,27 mg g -1 . O desempenho analítico foi avaliado por meio dos parâmetros, limite de detecção, limite de quantificação, precisão intra-dia e fator de pré-concentração e os valores encontrados foram de 0,39 μg L -1 , 1,30 μg L -1 , 0,06 % e 50, respectivamente, sendo a faixa linear do método de 1,5 a 1000 μg L -1 . A exatidão do método foi avaliada a partir de análises de material de referência certificado de água (APS-1071), além dos testes de recuperação em amostras de etanol combustível, com valores de recuperação na faixa de 80-120%.
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    Determinação eletroquímica do agrotóxico tiabendazol extraído e pré-concentrado em amostras de tomate pela técnica de ponto nuvem usando eletrodo de diamante dopado com boro
    (Universidade Federal de Goiás, 2019-03-29) Caixeta Neta, Antônia; Andrade, Leonardo Santos;; Andrade, Leonardo Santos; Alves, Vanessa Nunes; Muñoz, Rodrigo Alejandro Abarza
    In Brazil, there is a significant consumption of tomatoes and, according to the report of the Program of Analysis of the Residues of Agrochemicals in Food (PARA) available by ANVISA, the tiabendazole (TBZ) fungicide was detected in some tomato samples analyzed. The detection of this substance is considered to be prohibited, since the TBZ is authorized only for application in seeds of the plant and, therefore, could not be found in fruits. Thus, electrochemical methods can be used for the determination of pesticides in complex samples and in low concentration levels, because they produce fast and reliable measurements, consuming small amounts of reagents. In this work, a procedure for the electroanalytical determination of TBZ fungicide in tomato fruits using boron-doped diamond electrode (BDD) was developed and validated using the cloud extraction and preconcentration (CPE) technique. The analytical technique used in this determination was the High Performance Liquid Chromatography coupled to an electrochemical detector (HPLC-EC), by the use of the BDD electrode. In order to evaluate the main variables of the CPE process, it was used a 24 complete factorial planning to optimize the parameters. The CPE optimized condition was achieved by the use of Tergitol (19% V/V), NaCl (0.83 g), ultrasonic stirring time of 15 min and temperature of 36 °C. Under these conditions, the preconcentration factor obtained was 5.7. The limits of detection and quantification obtained were 2.7 × 10-8 mol L-1 and 5.5 × 10-8 mol L-1 , respectively. The average recoveries obtained in 3 days were satisfactory, varying between 80.7% and 115.1%, which demonstrates the good accuracy of the developed method. In the application of the method in commercial tomatoes, TBZ was detected in one of the samples analyzed. The differential pulse voltammetry (DPV) technique was also investigated for the electroanalytical determination of TBZ fungicide in tomato fruit (extracted and pre-concentrated by CPE) using BDD electrode in order to increase the analytical frequency. The use of DPV technique increased the analytical frequency by approximately 90 times compared to the HPLC/EC technique.
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    Tratamento de lixiviados de aterro sanitário combinando coagulação (sulfato de alumínio) e técnicas eletroquímicas (diamante dopado com boro)
    (Universidade Federal de Goiás, 2019-03-08) Oliveira, Mayra Silva de; Andrade, Leonardo Santos;; Andrade, Leonardo Santos; Sarmento, Antover Panazzolo; Santos, Maria Rita de Cássia
    Landfill leachate contains a wide variety of organic and inorganic compounds that give the effluent high toxicity, high organic load and low biodegradability. Due to its complex composition, this effluent has acquired high research interest in the use and combination of new treatment technologies which can provide the balance of the environment. This study presents and discusses the results obtained in the treatment of raw landfill leachate with a combination of coagulation-flocculation and electrochemical techniques using a filter-press reactor with a boron-doped diamond electrode. The treatment success was demonstrated by the quality of treated water, which was evaluated based on parameters such as color, odor, turbidity, chemical oxygen demand, biochemical oxygen demand, free and total chlorine, total nitrite and nitrate, ammonia and microbiological tests (mesophiles and thermotolerant coliforms). The best conditions for coagulation-flocculation involved a dosage of 20 mL/L of Al2(SO4)3 at pH 6.0 followed by electrochemical treatment by 3 h. To reduce the energy consumption, the best condition for electrochemical treatment was performed by the application of different limiting current density step sequences, in the order to keep the applied current always closer to that in which the process is mostly controlled by diffusion (limiting current, Ilim). This strategy reduced the energy consumed in removing the organic load by up to 40% while maintaining a similar effective mineralization rate (> 90% removal) between stages. Microbiological tests revealed that the number of mesophiles was reduced by more than twelve orders of magnitude after electrolysis, indicating the important sanitizing effect caused by the HClO/chloramine species generated in the process. The parameters color, turbidity and ammoniacal nitrogen were completely eliminated from the treated landfill leachate at the end of the electrolysis process.
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    Avaliação da fibra da bucha vegetal (Luffa cylindrica) e das folhas de taboa (Typha angustifolia L.) como materiais adsorventes para a remoção do agrotóxico tebuconazol de água contaminada
    (Universidade Federal de Goiás, 2019-03-18) Silva, Thiago Felipe; Freitas, Silvia de Sousa;; Freitas, Silvia de Sousa; Alves, Vanessa Nunes; Sarmento, Antover Panazzolo
    Agrochemicals are industrialized products made up of a broad junction of chemicals used to combat pest resistance in plantations. The high consumption and the inappropriate disposal of these products can generate great environmental impacts. Adsorption processes employing alternative materials have been evaluated to remove them from the environment, especially from water sources for human consumption. In this work, the adsorption capacity of the materials: bush (Luffa cylindrica) and taboa (Typha angustifolia L.) was evaluated for the removal of the tebuconazole pesticide from aqueous medium. The analytical methodology used to quantify the pesticide in the solution, after the removal, was High Performance Liquid Chromatography with UV-vis detector (HPLC-UV). The values of LD and LQ in the chromatographic method were 0.01 mg L-1 and 0.10 mg L-1 , respectively. The materials were characterized by the FTIR technique, being observed in both materials the presence of functional groups characteristic of lignocellulosic compounds. The micrographs (SEM) indicated the heterogeneity and irregularity of the surface in both materials. The pH at the zero charge point (pHPCZ) was 6.15 for bush (Luffa cylindrica) and 6.62 for taboa (Typha angustifolia L.). The ability to remove tebuconazole from the aqueous medium by the materials was evaluated as a function of the adsorbent dosage, contact time and concentration of the pesticide. The dosages of 20 and 10 g L-1 were used in the adsorption tests with the bush (Luffa cylindrica) and taboa (Typha angustifolia L.), respectively. The kinetic study showed that the adsorption equilibrium was obtained after 40 minutes of contact and the experimental data were better adjusted by the Avrami model, for both materials. Regarding the study of tebuconazole concentration, it was observed that the removal is little influenced by the increase in tebuconazole concentration in the medium, remaining relatively constant in the concentration range evaluated, for both materials. The experimental data were well adjusted by all models of isotherms evaluated (Langmuir, Freundlich and Sips), with R 2> 0.99. The maximum adsorption capacity (Qmax) of tebuconazole was 8.5651 mg g-1 for bush (Luffa cylindrica) and 13.6419 mg g-1 for taboa (Typha angustifolia L.).The use of the adsorbents to remove the pesticide in natural water sample presented results very similar to those observed when using deionized water, showing that the removal efficiency of these materials is not affected by the type of aqueous matrix. The alternative column adsorption process showed satisfactory removal results (~ 51% removal for bush and ~ 75% removal with taboa), in a significantly shorter time (3-4 min) in relation to the batch process (40 min). Thus, it can be concluded that the adsorbent materials evaluated, bush (Luffa cylindrica) and the taboa (Typha angustifolia L.) can be used for the removal of the tebuconazole pesticide from aqueous medium.
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    Avaliação química de polissacarídeos e propriedades antimelanoma da heterogalactana proveniente do macrofungo Hypsizygus marmoreus
    (Universidade Federal de Goiás, 2019-02-02) Oliveira, Ruberney da Silva de; Carbonero, Elaine Rosechrer;; Carbonero, Elaine Rosecher; Freitas, Lorena Ramos de; Leal, Maria Carolina Di-Medeiros
    Hypsizygus marmoreus, popularly known as "Bunashimeji" in Japan, is an edible mushroom highly valued for its medicinal properties. Several therapeutic effects have been reported for this species as immunomodulatory, antitumor, antiviral, cytotoxic, antifungal, antihypertensive, antioxidant, anti-inflammatory, antiproliferative, regulation of obesity and insulin resistance, antiatherosclerotic, which have been attributed to crude extracts, fractions and/or isolated compounds (proteins, lipids, polysaccharides, oligopeptides and secondary metabolites) obtained from the basidiocarp and/or mycelium and filtered from the submerged culture. Considering the diversity of polysaccharides present in each fungal species, as well as their importance in modifying the biological response, the H. marmoreus mushroom is unexplored in this area, representing an important species to be studied. For this, the aqueous and alkaline extractions were performed to obtain the polysaccharide extracts, which were purified by freezing/thawing and precipitation with Fehling's solution. The structural determination was performed by NMR spectroscopy, monosaccharide composition analysis and methylation by GC-MS and partial hydrolysis. From the cold aqueous extract was isolated a fucomannogalactan (fraction Hm-PF2AF, Hm-FMG; Mw = 17,670 Da) contained (-16)-linked galactopyranosyl main chain, partially substituted at O-2 with non-reducing ends of α-L-Fucp and -Manp; a branched α-glucan with glycosidic bonds of the type (1→4) and (1→6) (Hm-MRSF2) with a glycogen-like structure and a branched -glucan with a Glcp-(1→3)-linked backbone, partially substituted at O-6 by non-reducing ends of -Glcp (Hm-S2AF). Fractionation of the cold water soluble fraction obtained from the alkaline extract (Hm-SK) resulted in two fractions containing glycogen and a -glucan (Hm-SFK and Hm-PFK) distinct from that previously mentioned. After elimination of glycogen by amylase treatment, the fractions obtained (Hm-TASFK and Hm-TAPFK, respectively) probably consist of branched -glucans containing a main chain of β-Glcp (16)-linked, which are partially substituted in O-3. Further analysis of structural characterization (2D NMR, methylation, partial degradation of Smith, among others) should be performed to confirm the structure of -glucans isolated and other fractions obtained in this study. In order to prove the effects of polysaccharides as biological response modifiers, the purified fractions (fucomannogalactan and -glucans) of H. marmoreus were submitted to evaluation of the antitumoral activities, in collaboration with Prof. Dr. Edvaldo da Silva Trindade and Dr. Stellee M. P. Biscaia from the Cell Biology Department of the Federal University of Paraná. Preliminary results of fucomannogalactan (Hm-FMG) demonstrated that heterogalactan was not cytotoxic, nor altered cell morphology, but was able to reprogram B16-F10 murine melanoma cells by modifying colony formation ability and cell migration, without changing cellular proliferation. In view of the promising in vitro antimelanoma effects of the Hm-FMG polysaccharide, it can be suggested that these polymers are responsible for part of the therapeutic properties conferred by this macrofungus. To confirm these findings, additional assays should be performed to prove the possible antitumor effects of purified fractions and the mechanism of action of these compounds.