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Item Compostos de coordenação visando o desenvolvimento de eletrodos para armazenamento e conversão de energia(Universidade Federal de Goiás, 2025-04-29) Campos, Iara Schlag Durães; Martins, Paulo Roberto; http://lattes.cnpq.br/0107474250870898; Martins, Paulo Roberto; http://lattes.cnpq.br/0107474250870898; Gomes, Danielle Cangussu de Castro; http://lattes.cnpq.br/5709288358367849; Gonçalves, Josué Martins; http://lattes.cnpq.br/8271818229699538In this work, two materials based on ZIF-67/Ni(OH)2 and CoFe-ZIF-67/Ni(OH)2 were obtained in order to evaluate their electrochemical performances in both energy storage and conversion. A class of compounds called MOFs are three-dimensional structure consisting of a metal center and organic ligands. One class of MOFs is called ZIFs, which are materials with a tetrahedral zeolite-type topology with a central element – typically Zn or Co – that connects to each other through oxygen atoms. Therefore, two MOFs (ZIF-67 and CoFe-ZIF-67) were synthesized through the reaction between their metal precursors (cobalt acetate and iron sulfate) with 2- methylimidazole, while Ni(OH)2 was synthesized, in-situ, using the Tower method followed by electrochemical treatment of the electrodes. The composites were obtained by deposition of MOFs on a 1 cm2 of a fluorine-doped tin oxide substrate (FTO), using the drop-casting technique, followed by the deposition of Ni(OH)2 on the modified electrodes with the MOFs using the spin-coating technique. Through the X-Ray Diffraction technique it was possible to identify that the MOFs are in their amorphous form. Nickel hydroxide is in fact a nickel glycerolate, with a single characteristic diffraction peak located in the region close to 2θ = 10°, and the composites are strongly influenced by the structure of the nickel glycerolate, since the only diffraction peak presented is in the same region of 2θ = 10°, however with less intensity. In addition, the morphology of the MOFs was studied through Transmission Electron Microscopy, demonstrating their nanoparticle structures with the presence of interference fringes with an average distance of 0,130 nm (CoFe-ZIF67) and 0,125 nm (ZIF-67). The Scanning Electron Microscopy technique was also used in morphological studies, helping to understand the way in which the material is deposited on the FTO substrate. Energy dispersive spectroscopy (EDS) also contributed to the identification of the chemical elements present in the samples, such as cobalt, nitrogen, carbon, nickel, iron and oxygen, depending on the sample analyzed.The oxidation states of the metals in the composites were defined by means of X-Ray Photoelectron Spectroscopy, and for both ZIF-67/Ni(OH)2 and CoFe-ZIF67/Ni(OH)2 there is the presence of Co2+, Co3+, Ni2+ and Ni3+ ions, in addition to Fe2+ and Fe3+ ions being found in the CoFe-ZIF-67/Ni(OH)2 composite. Through electrochemical studies, such as cyclic voltammetry processes and galvanostatic charge and discharge curves, it was possible to identify that the most promising material in the area of energy storage was ZIF-67/Ni(OH)2, since it presented the highest specific capacity (106,99 mAh.g-1 at 1 A.g-1 ) and its capacity retention was 71,63% after 5000 consecutive charge and discharge cycles at 12 A.g-1 , in addition to their energy storage processes being characterized as diffusional and faradaic. Electrochemical Impedance Spectroscopy studies were performed to investigate the charge transfer resistance values for the five materials. Based on the values found, the CoFe-ZIF-67/Ni(OH)2 composite exhibits the lowest charge transfer resistance value related to the oxygen evolution process (7,6 Ω). Focused on the area of energy conversion, the material that presented the lowest overpotential value (at a current of 10 mA) in the water oxidation process during linear voltammetry readings was CoFe-ZIF-67/Ni(OH)2, with a value of 0,43 V, in addition to exhibiting good stability x and durability over 10 consecutive hours of application of a fixed current of 10 mA. The development of these new composites aggregatesin different areas: ZIF67/Ni(OH)2 for energy storage systems and CoFe-ZIF-67/Ni(OH)2 for energy conversion systems. Both materials showed positive results in their respective areas of study.Item Estudos químico-biológicos de mangaba (Hancornia speciosa Gomes) oriunda de comunidades extrativistas de Goiás visando aplicação industrial(Universidade Federal de Goiás, 2025-03-26) Silva, Cleysla Mendes da; Severino, Vanessa Gisele Pasqualotto; http://lattes.cnpq.br/0286065758729632; Severino, Vanessa Gisele Pasqualotto; Fill, Taicia Pacheco; Foglio, Mary AnnEmbargado.Item Estudos teóricos do íon SCN- suportado em Pd13(Universidade Federal de Goiás, 2025-04-25) Souza, Joezer Barros de; Guimarães, Freddy Fernandes; http://lattes.cnpq.br/6780812627526129; Guimarães, Freddy Fernandes; Oliveira, Anselmo Elcana de; Felicíssimo, Viviane CostaEmbargadoItem Desenvolvimento de heteroestruturas derivadas do óxido de tungstênio para sensores de gases(Universidade Federal de Goiás, 2025-02-20) Pereira, Gustavo Nicolau; Mello, Hugo José Nogueira Pedroza Dias; http://lattes.cnpq.br/9322890299309036; Barbosa, Martin Schwellberger; http://lattes.cnpq.br/6591454488385347; Barbosa, Martin Schwellberger; Masteghin, Mateus Gallucci; Martins, Paulo Roberto; Mello, Hugo Jose Nogueira Pedroza DiasThis work explored the synthesis of materials derived from metal oxides and sulfides for applications in gas sensor devices. The focus was on studying how the introduction of heterojunctions can alter the sensor response of the material to analytes in the gas phase. Specifically, the modification of materials derived from tungsten oxide (WO3) with tin sulfide (SnS2) phases. To analyze the effect of this modification in a sensor device, the responses to gases H₂ (flammable), CO, NO₂ (toxic), and acetone (a known biomarker for diseases) were examined. The materials analyzed demonstrated high selectivity for NO₂, especially at high concentrations (50/100 ppm), with particular emphasis on the SnS₂/WO₃ (10:1) material, which achieved a sensor response of 1995 at 100°C. For gases such as H₂ and acetone, significant responses were observed at higher temperatures (300°C), while carbon monoxide (CO) showed low sensitivity across all materials. A thermal treatment was also applied to the materials to study whether there would be any changes in their overall behavior. Although the thermal treatment enhanced the sensor response for some materials, such as SnS₂/WO₃ (1:10) in acetone detection, it also brought disadvantages. At certain temperature ranges, there was a loss of sensor response, as observed in SnS₂/WO₃ (10:1) at 100°C. Furthermore, the presence of the heterojunction influenced the response and recovery times. For acetone, some materials exhibited significantly longer recovery times, while others reduced these times compared to the seed material.Item Desenvolvimento de uma metodologia fisicamente inspirada no princípio da mínima polarizabilidade para o cálculo de propriedades optoeletrônicas de polímeros orgânicos(Universidade Federal de Goiás, 2025-02-24) Araujo, Ana Carolina Felisberto; Oliveira, Heibbe Cristhian Benedito de; http://lattes.cnpq.br/5995553993631378; Oliveira, Heibbe Cristhian Benedito de; Sanches Neto, Flávio Olimpio; Qadir, Muhammad IrfanPolymers are macromolecules of significant industrial interest due to their versatility, including their potential application in the design of optical devices. Properties such as the refractive index and Abbe number are closely related to the optical performance of these materials and their technological applications. Therefore, predicting optical properties is essential, as they are directly dependent on the linear polarizability (α), which quantifies the susceptibility of a molecule’s or material’s electronic cloud to distortion under an external electric field. Density Functional Theory based methods employ the electronic density as a fundamental quantity for electronic structure calculations, providing computationally efficient and highly accurate predictions of optical properties in organic materials, such as α. This approach offers a variety of functionals with different levels of correction and approximation for the exchange-correlation potential. Among these, we employ range-separated hybrid (RSH) functionals, which explicitly account for electron-electron interactions by introducing a range-separation parameter (ω), allowing for a transition between short- and long-range interactions. In this study, we investigate the optimization of the ω parameter in RSH functionals based on a physically motivated principle known as the minimal polarizability principle (MPP). The core concept of this approach derives from the maximum hardness principle, which states that a system tends to evolve toward a minimum polarizability value to achieve greater stability. By applying this principle, we developed and assessed a new optimization scheme for the ω parameter in RSH functionals based on MPP and evaluated the impact of this optimization on the optoelectronic properties of organic polymers. The calculated α and refractive index values showed good agreement with experimental data, with higher ω values highlighting the increased contribution of long-range interactions in determining these properties. The polymers investigated to validate the proposed methodology were polythiophene (PT), poly(1,4-phenylene) (PB), trans-polyacetylene (trans-PA), cis-polyacetylene (cis-PA), and polybutadiene (PBT), while the optimized functionals were LC-BLYP, LC-HPBE, and B97XD.Item Síntese seletiva de tiocarbonatos cíclicos utilizando catalisadores básicos(Universidade Federal de Goiás, 2024-11-18) Camargo, Maria Eduarda de Souza; Chagas, Rafael Pavão Das; http://lattes.cnpq.br/9712618482518275; Chagas, Rafael Pavão Das; Matos, Gabriela Ferreira; Ferreira, Leonildo AlvesThe search for new carbon sources for the production of plastic polymers, pharmaceuticals and agrochemicals, among others, is essential. The use of carbon disulfide (CS2) is a viable alternative and can be used as a raw material for the production of thiocarbonates and various other industrially relevant substances. The aim of this work is to develop a methodology that employs mild conditions to produce cyclic thiocarbonates from CS2 and epoxides, using basic catalysts such as metal hydrides and hydroxides. Experiments were carried out to evaluate the catalytic capacity of various hydrides and hydroxides, in which sodium hydride and sodium hydroxide stood out significantly, leading to quantitative and totally selective conversions of CS2 into the respective cyclic dithiocarbonates. It is believed that the nucleophilicity of the hydroxide anion and the solubility of these substances were decisive for these results. The reaction conditions of the catalytic system were optimized, with the best results obtained at a temperature of 50 °C, reaction time of 2 hours and catalytic load varying between 2 and 5 mol%, depending on the type of epoxide used. Finally, a variety of epoxides were tested to assess the replicability of the method. Evaluation of the results revealed that epoxides with electron-withdrawing substituents, capable of increasing the electrophilicity of the ring, showed higher conversion rates while maintaining high selectivity. On the other hand, epoxides without these groups or containing bulky groups close to the epoxide ring showed low conversion rates or were not converted at all. This work has shown that a simple, low-cost substance such as sodium hydroxide can be used as a highly efficient and selective catalyst for the production of cyclic dithiocarbonates from CS2 and epoxides.Item Determinação de pesticidas em amostras de leite materno por espectrometria de massas ambiente empregando paper spray ionization(Universidade Federal de Goiás, 2024-12-17) Ferreira, Pedro Augusto Barbosa; Chaves, Andréa Rodrigues; http://lattes.cnpq.br/6064014965252121; Chaves, Andréa Rodrigues; Soares, Francielle Queiroz; Oliveira, Gisele Augusto Rodrigues DeThe increase in agricultural production in Brazil has driven the excessive and indiscriminate use of pesticides. These substances are often present, even at trace levels, in various environmental and food matrices. However, given their widespread dissemination and persistence in these environments, combined with human exposure to these residues, they can be detected in different biological fluids, including breast milk. Due to the complexity of this matrix and the low levels of analytes present, the development of strategies for sample preparation is necessary to achieve the desired sensitivity. One strategy to overcome this challenge lies in ambient mass spectrometry employing the ionization technique known as paper spray ionization (PSI-MS). The PSIMS technique typically uses a triangularly cut chromatographic paper substrate for sample application. This substrate allows for chemical modifications that can enhance the sensitivity and selectivity of the desired methods. Modifying the paper using molecularly imprinted polymers (MIPs) and restricted access materials (RAMs) are promising choices to improve the sensitivity and selectivity of PSI-MS analyses. MIPs enable highly selective extraction of target analytes, while RAMs help eliminate endogenous matrix compounds that could reduce the analytical sensitivity of the PSI-MS approach. Thus, in this study, MIP and RAM immobilizations were synthesized and characterized to evaluate their use as modifiers for the paper substrate in PSI-MS applied to pesticide analysis in breast milk samples. The MIP was synthesized using glyphosate as the template molecule, methacrylic acid as the functional monomer, diethylene glycol dimethacrylate as the crosslinking agent, and azobisisobutyronitrile as the radical initiator, under reaction conditions of 24 hours at 60°C in a nitrogen atmosphere. The RAM was produced using C-18 particles, onto which bovine serum albumin (BSA) was immobilized on the surface. The polymers developed were characterized by thermogravimetric analysis/derivative thermogravimetric analysis-simultaneous differential thermal analysis (TGA/DTGADTA), scanning electron microscopy (SEM), and Fourier-transform infrared spectroscopy (FTIR). The results confirmed that the materials were obtained as expected. After characterization, the polymers were immobilized on the paper surface and subjected to PSI-MS analysis for the determination of glyphosate in breast milk samples. Among the modifying phases evaluated, the highest analytical sensitivity was obtained using the RAM phase, which was selected for subsequent tests. The developed PSI-MS method exhibited linearity in the range of 50 to 600 µg mL⁻¹ with R² = 0.9915. The method's figures of merit—precision, accuracy, recovery, and matrix effect—were evaluated. The precision ranged from 1.3% to 8.7%, and recovery ranged from 104.7% to 113.7%. Preliminary results for glyphosate determination indicated that the synthesized polymers are promising as modifiers for PSI-MS substrates, allowing the selective determination of glyphosate in breast milk. Breast milk samples from volunteer patients were analyzed, and glyphosate was detected at quantifiable levels within the working range in five samples, with two above the limit of detection (LOD) and one below. In twelve samples, the analyte was not detected. The developed RAM-PSI-MS methodology proved to be a promising alternative for glyphosate determination in breast milk samples.Item Síntese e Caracterização de Novos Complexos de Ru(III) com Ligantes Nitrogenados Heterocíclicos e Potencial Atividade Antitumoral(Universidade Federal de Goiás, 2017-05-31) Noronha, Linneker Fernandes de; Souza, Aparecido Ribeiro de; http://lattes.cnpq.br/7884708272070266; Souza, Aparecido Ribeiro de; Quintino, Michelle Pereira; Chagas, Rafael Pavão dasCancer is a genetic disease caused by mutations in the DNA that can develop in any part of the body. Its treatment follows different approaches, including chemotherapy, which can be quite aggressive. Ruthenium compounds associated with heterocyclic nitrogen ligands have been well studied because of their promising antitumor activity, some of them already present good results and are in the preclinical phase, such as [H-Imidazole] [trans-RuCl4(imidazole)(DMSO)] (NAMI-A) and [H-indazole][trans-RuCl4(indazole)2] (KP1019). In this work, six Ru coordination compounds were synthesized, four of them being unpublished, with heterocyclic nitrogenous ligands 2-(1H-pyrazole)-1-pyridine (L1 ), (1-(pyridine-2)-1H-pyrazole-4-il)methanol (L2 ), ethyl-4-((1-(pyridine-2)-1H-pyrazole-4-il)methyl)pipyrazine-1-carboxylate (L3 ) e 1-(4-((1-(pyridine-2-)-1H-pyrazole-4-)methil)pipyrazine-1-)etanone (L4 ) which are believed to have potential antitumor activity. The compounds were synthesized by reaction under reflux and characterized by: infrared and Uv/Vis spectroscopy, 1H nuclear magnetic resonance spectroscopy, elemental analysis (CHNS), single crystal x-ray diffraction and cyclic voltammetry. The binders used have the same target nucleus for coordination consisting of a pyridine ring and a pyrazole ring. The ligands showed two different modes of coordination to the metal, a bidentate, forming a chelate with the metal, occurs with the ligands L 1 and L 2 and another monodentate, where the ligand coordinates with the metal only by the nitrogen atom of the pyrazole ring, the which occurs with ligands L 3 and L 4 .Item Explorando o potencial do CO2 por meio dos líquidos iônicos de fase suportados para produção de carbonatos cíclicos(Universidade Federal de Goiás, 2024-10-31) Silva, Blendo Almeida da; Chagas, Rafael Pavão das; http://lattes.cnpq.br/9712618482518275; Qadir, Muhammad Irfan; http://lattes.cnpq.br/8517524064523950; Qadir, Muhammad Irfan; Martins, Paulo Roberto; Scholten, Jackson DamianiThe fixation of CO2 into cyclic carbonates is a highly efficient synthetic route, recognized for its atomic economy and wide utility. Ionic Liquids have garnered interest due to their CO2 absorption capacity and chemical stability, making them attractive study targets. This work proposes investigating SILP catalysts for converting epoxides into cyclic carbonates under mild reaction conditions. The catalysts of trichlorozincate of 1-methyl-3-(3- (trimethoxysilyl)propyl)imidazolium, chloride of 1-methyl-3- (trimethoxysilylpropyl)pyridinium, and chloride of 1-methyl-3-(3- (trimethoxysilyl)propyl)imidazolium were synthesized, supported on Al2O3, and characterized by nuclear magnetic resonance, infrared absorption spectroscopy, and thermal analysis. The catalytic study of the SILP-Cl catalyst, it was observed that epoxides containing electron-withdrawing groups in their structure showed the best results, with epichlorohydrin achieving 100% conversion. Additionally, 2-(phenoxymethyl)oxirane (entry 2) and 2-((o-tolyl oxy)methyl)oxirane showed conversion results close to 90%, along with small epoxides like propylene oxide and 1,2-epoxybutane, which also showed satisfactory results. For the SILP-ZnCl3- catalyst, the results were similar to those obtained by the SILP-Cl catalyst, especially under the condition of 100 mg of catalyst and 120°C. Epoxides without this electron-withdrawing effect achieved low conversion values, such as tert-butyl glycidyl ether, which reached around 30% conversion. However, both catalysts maintained high selectivity for cyclic carbonate production. The recyclability tests of the catalyst demonstrated slightly decreased in conversion over four cycles, while maintaining selectivity above 90% without catalyst leaching. The obtained results indicate the efficacy of the established reaction conditions, highlighting the influence of the size and structure of the epoxides on conversion and selectivity.Item Abordagens para análise de n-nitrosaminas em medicamentos utilizando DPX-LC-MS e DART-MS(Universidade Federal de Goiás, 2023-12-19) Batista Junior, Almir Custodio; Chaves, Andréa Rodrigues; http://lattes.cnpq.br/6064014965252121; Chaves, Andréa Rodrigues; Coltro, Wendell Karlos Tomazelli; Freitas, Carla Santos deN-Nitrosamines (NAs) are molecules characterized by a deprotonated amine group linked to a nitroso group, usually formed through the reaction of secondary or tertiary amines with nitrosating agents. NAs are commonly found as impurities in various products, such as processed foods and cosmetics. These molecules are the subject of study due to their potential mutagenic and carcinogenic properties. In 2018, NAs were discovered in medicines containing the active ingredient valsartan. In sartan medicines, the occurrence of NAs was initially linked to the synthesis of the active pharmaceutical ingredient (API), as the reaction medium may contain precursor amines for NAs, as well as a nitrosating agent. Through more in-depth studies, it has been confirmed that the degradation of the API or its interaction with the packaging material could lead to the formation of NAs. These discoveries prompted global regulatory agencies to establish guiding principles regarding the presence and maximum allowable concentrations of these molecules in such medicines. Aiming to assess the content of NAs in medicines, efficient and sensitive analytical methods have been developed. The challenge in analyzing NAs in medicines lies in the low concentration of these analytes, as they are found in this matrix in the order of ng of N-nitrosamine per mg of the medicines. The literature presents various chromatographic methods coupled with mass spectrometry (MS) applied in such analyses. Both liquid chromatography (LC) and gas chromatography (GC) techniques provide sensitive and selective methods for the analysis of NAs in medicines. However, LC methods have advantages over GC as it allows the analysis of thermally unstable and non-volatile compounds. Due to the presence of the API in the sample and the low concentration of these impurities, the determination of NAs can be compromised by various factors, such as matrix effects, carryover effects, and the compromise and contamination of the LC-MS system. Thus, the sample preparation step proves to be important, aiming at the extraction, purification, and pre-concentration of NAs. Additionally, advances in mass spectrometry have led to the development of ambient ionization techniques designed to analyze samples that are either unprocessed or minimally modified in their native environment. These techniques enable the analysis of samples in situ, often in a non-destructive manner. Another important factor currently is the adaptation of analysis protocols with sustainable principles advocated by green chemistry, which aim to reduce the use of solvents and samples, minimize risks, decrease energy consumption, and reduce waste generation. Therefore, the present study introduces new approaches to the analysis of NAs in medicines that have not yet been explored in the literature. Chapter I demonstrates the use of a miniaturized sample preparation technique for the separation and pre-concentration of NAs in medicines followed by LC-MS analysis. Conversely, Chapter II presents the application of an ambient ionization technique coupled with mass spectrometry for the assessment and quantification of NAs in medicines.Item Estudo da inserção de grafeno em catalisadores de PtSn para a oxidação de etanol(Universidade Federal de Goiás, 2022-02-21) Bastos, Tarso Leandro; Colmati Junior, Flavio; http://lattes.cnpq.br/0231242349462585; Colmati Junior, Flávio; Ciapina, Eduardo Gonçalves; Martins, Paulo RobertoFuel cells are portable electrochemical converters that generate electricity using renewable fuels and can act as high-efficiency energy sources. When fed with ethanol, they lose performance due to electrode poisoning. To mitigate this problem, noble metals are used in the electrodes in addition to the addition of elements to the electrocatalysts, increasing the production cost while the problem persists. Thus, this study seeks to increase the efficiency of ethanol oxidation by modifying the carbon support with graphene, where the metallic phase is anchored, and to verify its influence on the general catalysis process. Electrocatalysts with carbon-graphene hybrid support were synthesized in different proportions, and a physical mixture of graphene with the carbon-supported electrocatalyst was prepared. Hybrid supported electrocatalysts showed higher electrochemical activity and stability in ethanol oxidation compared to carbon supported electrocatalyst, with an increase of 132% in alkaline medium. In the physical mixture, the addition of graphene generated a 10% decrease in the amount of metallic phase needed, obtaining the same performance as the pure electrocatalyst. While in acidic medium, in addition to the 10% decrease, the physical mixture exhibited a much superior performance to the pure electrocatalyst. The results showed that the influence of graphene depends on its interaction with the electrocatalyst, while promoting an increase in the performance of ethanol oxidation.Item Análise de imagens para a determinação de parâmetros de cinética química(Universidade Federal de Goiás, 2024-05-31) Oliveira, Isabella Moura e; Oliveira, Anselmo Elcana de; http://lattes.cnpq.br/0369339073291948; Oliveira, Anselmo Elcana de; Guimarães, Freddy Fernandes; Coelho, Clarimar JoséA low-cost experimental apparatus was built from a video capture device (smartphone) and a lighting box. This system was used to determine the rate constant of fading of Phenolphthalein in NaOH (pH > 10) using video analysis. All computational development was carried out using free software. The analytical methodology developed is statistically equivalent to the determination made by the reference spectrophotometric method (λ = 550 nm). A case study using categorization was designed to evaluate the use of video analysis methodology as a teaching tool in a class on the Experimental Physical Chemistry course. The results obtained reinforce that the methodology developed showed good agreement between the results obtained in the classroom and those in the literature. There was also a positive interest among students in the alternative approach, highlighting the practicality and mobility offered by the new methodology. In other words, this methodology can also be effective in teaching laboratories, especially as a low-cost alternative to the use of UV/Vis spectrophotometers.Item Análise de íons inorgânicos em resíduos de explosão utilizando microssistemas eletroforéticos(Universidade Federal de Goiás, 2018-08-01) Pinheiro, Kemilly Mara Pires; Coltro, Wendell Karlos Tomazelli; http://lattes.cnpq.br/8302650734477213; Coltro, Wendell Karlos Tomazelli; Rosseto, Renato; lonashiro, Elias YukiThis study describes the development of an analytical methodology based on the use of microchip electrophoresis (MSE) devices integrated with capacitively coupled contactless conductivity detection (C4D) for the separation and detection of inorganic anions in post-blast explosive residues. The best separation condition was achieved using a running buffer composed of 35 mmol L-1 lactic acid, 10 mmol L-1 histidine and 0.070 mmol L-1 cetyl(trimethyl ammonium) bromide. For C4D measurements, the highest sensitivity was obtained applying a 700 kHz sinusoidal wave with excitation voltage of 20 Vpp. The separation of Cl-, NO3-, NO2-, SO42-, ClO4- and ClO3- was performed within ca. 150 s with baseline resolution and efficiencies between 4.4x104 and 1.7x105 plates/m. The found limits of detection ranged between 2.5 and 9.5 μmol L-1. Also, excellent repeatability was obtained, with relative standard deviation lower than 0.8%, 8.8% and 13.5% for the injection time, for the intensity and the peak areas, respectively. Lastly, real samples of post-blast explosive residues were analyzed on the MSE-C4D devices obtaining successfully the determination of Cl-, NO3- and SO42-. The achieved concentration values varied between 2301,610 µg g-1 for Cl-, 805,490 µg g-1 for NO3- and 1453,270 µg g-1 for SO42-. It was also possible to compare the anionic profile of residues of an improved explosive device and a commercial explosive emulsion, confirming the improved explosive device composition, based on ammonium nitrate fuel oil (ANFO). The approach reported herein has provided short analysis time, instrumental simplicity, good analytical performance and low cost. Furthermore, the MSE-C4D devices emerge as a powerful and portable analytical platform for on-site analysis demonstrating to be a promising tool for the crime scene investigation.Item Determinação de escopolamina e butilescopolamina em amostras de bebidas, urina e comprimidos de Buscopan® usando microssistemas eletroforéticos(Universidade Federal de Goiás, 2023-08-08) Santos, Hellen Inácia dos; Coltro, Wendell Karlos Tomazelli; http://lattes.cnpq.br/8302650734477213; Coltro, Wendell Karlos Tomazelli; Jesus, Dosil Pereira de; Chaves, Andréa RodriguesThe number of cases in which scopolamine (SCO) was used for both recreational and predatory purposes has increased dramatically in recent decades. Linked to this, there is a concern about obtaining SCO through thermal degradation of butylscopolamine (BSCO) – an active ingredient of Buscopan® – a drug sold without a medical prescription. In this study, mixtures containing SCO and BSCO were separated and detected on a microchip electrophoresis (ME) device with integrated capacitively coupled contactless conductivity detection (C4D) using a running buffer composed of 40 mmol L-1 of butyric acid and 25 mmol L-1 of sodium hydroxide (pH 5.0). The separation was performed within ca. 115 s with a resolution of 1.3 and separation efficiency of 1.4x105 and 1.5x105 theoretical plates m-1 for SCO and BSCO, respectively. The limit of detection was 1.1 μmol L-1 for both species and the developed method revealed satisfactory repeatability with relative standard deviation (RSD) values for forty-eight injections between 4.8 and 9.4% for peak areas and lower than 3.3% for migration times. Furthermore, inter-day precision was evaluated for sixteen injections (a sequence of four injections performed over four days), and RSD values were less than 6.6% for peak areas and 2.2% for migration times. Satisfactory recovery values (95 – 114 %) were obtained for all evaluated beverage samples (cachaça, vodka, whiskey, beer, coke soft drink, and grape juice) as well as for artificial urine samples (95 – 107 %). Finally, the conversion of BSCO into SCO was observed after simple heating procedure of Buscopan® sample (not subject to medical prescription), which was successfully confirmed through analysis by capillary electrophoresis coupled to the mass spectrometry (CE-MS). Based on the reported results, the use of ME-C4D devices has demonstrated a huge potential for applications in the forensic chemistry field.Item Enhancing accuracy in predicting optical properties of explicitly solvated systems: a comprehensive approach through long-range separated tuning of RSH functional and sequential QM/MM(Universidade Federal de Goiás, 2023-07-31) Matias, Pedro Henrique Ferreira; Oliveira, Heibbe Cristhian Benedito de; http://lattes.cnpq.br/5995553993631378; Oliveira, Heibbe Cristhian Benedito de; Ramalho, Teodorico de Castro; Colmati Junior, FlavioThe properties of molecular systems are generally measured experimentally in solution. In a theoretical context, molecular modeling is done in vacuum, leading to discrepancies when comparing theoretical results with the experimental ones. In light of this, the use of solvation methods become necessary. However, existing methodologies do not allow optimizing the separation parameter of electronic interactions in RSH functionals ω. An approach to combine functional optimization of the functionals with explicitly solvated organic systems, such as para-Nitroaniline and Phenol Blue, was developed by this work. The explicit solvation was performed using the S-QM/MM methodology with ASEC-FEG approximations. The optimization process was performed using the JGAP scheme with a Golden Ratio-based search algorithm to minimize the number of calculations. RSH functionals are noteworthy for improving the description of photoelectronic properties, hence we decided to study such properties. Firstly, electronic excitation and non-linear optical properties calculations were performed for para-nitroaniline to verify the change in photophysical properties with functional optimization. The properties were evaluated as well for Phenol Blue systems, which has well-elucidated optoelectronic properties, to validate the methodology. Finally, the results showed that the proposed methodology is successful in explicit solvation. Photophysical properties were improved by circa 20%, in high polar systems, for para-Nitroaniline and Phenol Blue. NLO Properties for Phenol Blue have an good agreement for first-hyperpolarizability in non-polar and protic-polar systems, and secondhyperpolarizability have the best results in protic-polar systems.Item Síntese e avaliação fotofísica de xantonas para sensores luminescentes(Universidade Federal de Goiás, 2023-02-28) Castilho, Nathália Santos; Coelho, Felipe Lange; http://lattes.cnpq.br/2304463718940575; Severino, Vanessa Gisele Pasqualotto; http://lattes.cnpq.br/0286065758729632; Severino, Vanessa Gisele Pasqualotto; Coelho, Felipe Lange; Kato, Lucilia; Lima, Dênis Pires deOrganic compounds that have in their structure an abundance of π electrons, rigidity and unsaturation occupy a prominent position in photophysical research. The compound 2-(2'-hydroxyphenyl) benzazole, known as cyclobenzazole, is widely studied in photophysics due to its fluorescence emission by the existence of the ESIPT mechanism. In this way, the luminescence of xanthones has been considered, since they present structural similarity with the cyclobenzazole. By synthesizing functional xanthones, new structures may have wide application, such as for fluorescent sensors. In this study, three 1-hydroxy-9H-xanthen-9-one derivatives (1,3-dihydroxy-9H-xanthen-9-one, 1,3-dihydroxy-4-nitro-9H-xanthen-9-one, one and 4-amino-1,3-dihydroxy-9H-xanthen-9-one) were synthesized and evaluated their photophysical properties, as well as the fluorescence emission mechanism of such compounds. In the photophysical evaluation, solutions with dichloromethane, ethanol and acetonitrile were used, at a concentration of 10-3 M. When measuring the maximum absorption of the compounds in the three types of solvents, it was verified that there was no significant variation, since there was no interaction between them. In the emissions, different interactions of the compounds with the employed solvents suggested the existence of a keto-enol equilibrium and the possible ESIPT mechanism, which would explain the fluorescence emission. The synthesis of the compound 5-hydroxy-2-(2-hydroxyphenyl)-6H-xanthen-[4, 3-d]-oxazol-6-one, derived from xanthone and with the benzazole ring in its structure, was developed, still requiring optimizations in the process. However, it was observed that at basic pH the structure emits a significant amount of fluorescence and can be used as a sensor. Therefore, new studies are suggested for a more in-depth photophysical evaluation and expansion of the chemical applicability of the synthesized structures.Item Efeito de solvatação explícita nas propriedades eletrônicas de peptóides fluorescentes via metodologia QM/MM sequencial(Universidade Federal de Goiás, 2023-02-23) Souza, Shamon Henrique Feitosa de; Oliveira, Heibbe Cristhian Benedito de; http://lattes.cnpq.br/5995553993631378; Oliveira, Heibbe Cristhian Benedito de; Franco Junior, Adolfo; Gargano, RicardoIn this work, we investigated the photophysical properties of four recently synthesized peptoids employing Quantum Chemistry calculations. The environment in which the solute is inserted can directly influence its properties, as the interactions of the solute with other molecules directly affect the geometric and electronic structure of the entire system. Therefore, in this work we use explicit solvation methods, in which each solvent molecule is explicitly treated and the total contribution of solvent molecules is included in the system, thus providing a better approximation between theoretical and experimental values. We studied the effect of explicit solvent treatment on the electronic properties of fluorescent peptoids, solvated in five different solvents, through computer simulations using a hybrid methodology (QM/MM). Sequentially to the Monte Carlo calculations (ASEC via DICE program) ab initio quantum calculations were performed in which we used several exchange-correlation functionals in order to identify which is the most suitable for the studied peptoids and analogous systems. The results obtained via theoretical calculations were compared with the experimental results published by Wender et al. (2016). With that, we developed a computational protocol comparable to the experimental values.Item Estudo da utilização do óleo de peixe visando à produção de nutracêuticos e biodiesel(Universidade Federal de Goiás, 2017-06-05) Oliveira, Ingryd Cristina de; Antoniosi Filho, Nelson Roberto; http://lattes.cnpq.br/5982964870999454; Antoniosi Filho, Nelson Roberto; Souza, Carolina Guimarães de; Duarte, Gabriela Rodrigues MendesThe use of waste from the fishing industry is emerging worldwide as a sustainable and attractive raw material alternative in environmental, economic and social aspects. Fish oil contains omega-3 polyunsaturated fatty acids (ω3-PUFA), ingredients in the pharmaceutical industry, in the production of nutraceuticals. On the other hand, it also contains saturated fatty acids (SFA), usable in the biodiesel industry. Given this context, the objective of this dissertation was the study of fish oil aiming its fractionation into saturated and unsaturated fatty acids (UFA). In this sense, the extraction and evaluation of oil from Clupea harengus (OR) residues were carried out through physical-chemical, thermal, and chromatographic techniques. Followed by the optimization of the chemical hydrolysis of the oil through 23 factorial design; and obtaining free fatty acids (FFA) using the conditions determined by planning. These FFAs were characterized, and with these results a new strategy of concentration of ω3-PUFA fatty acids was proposed: chemical hydrolysis, followed by crystallization at low temperatures in two steps in the absence of solvents. The research showed that OR has a high content of UFA (71.81%) and ω3-PUFA (17.44%). However, triacylglycerides are difficult to fractionate. The optimal condition for the hydrolysis found is that the catalyst is at 22% m/m; temperature of 90 oC; and reaction time of 2 h. The hydrolysis was effective, with the acidity index increasing from 7.68 mg KOH/g to 172.22 mg KOH/g, and did not significantly affect the UFA content. Two-step crystallization (10 oC and -10 oC) decreased SFA levels by 39.90%, but there was also a decrease in ω3-PUFA of 11.11%. The overall yield was 54% to 60%. The obtained concentrate can be considered a rich source of UFA with a total amount of 83.43%. Among these, 16.17% are ω3-PUFA and 11.78% are EPA + DHA. Thus, the oil extraction, hydrolysis, and characterization procedures were successful. However, the fractionation procedure of free fatty acids at low temperatures needs further studies.Item Cerumenolomic applied to Veterinary Medicine for the diagnosis of intoxication and of the metabolic profile of animals(Universidade Federal de Goiás, 2019-08-08) Barbosa, João Marcos Gonçalves; Antoniosi Filho, Nelson Roberto; http://lattes.cnpq.br/5982964870999454; Antoniosi Filho, Nelson Roberto; Fiovavanti, Maria Clorinda Soares; Oliveira, Anselmo Elcana deMedicina veterinária é uma das atividades mais antigas da história humana. O desenvolvimento de novos métodos em ciência veterinária é de grande urgência devido a sua importância em garantir o bem-estar animal, o qual é determinante para a economia global, principalmente em relação aos animais de pecuária. Sendo assim, o desenvolvimento de métodos que permitam uma análise de uma maneira rápida, efetiva, de grande acurácia, indolor e não-invasiva é extremamente importante. Nesta dissertação, um método é apresentado – aqui chamado por cerumenolômica- empregando os metabólitos orgânicos voláteis (MOVs) exalados pelo cerúmen (cera de ouvido) como um potencial biofluido que pode ser útil em ciência veterinária para aplicação em pesquisa em animais de pecuária. Amostras de cerúmen de raças brasileiras de bovinos e ovelhas foram coletadas na Escola de Veterinária e Zootecnia da Universidade Federal de Goiás (EVZ-UFG) e foram analisadas em um Cromatógrafo a Gás acoplado a um Espectrômetro de Massas por injeção de amostra via Headspace (CG-EM/HS) e, por fim, os dados dos cromatogramas foram submetidos à ferramentas de estatística multivariada. A cerumenolômica permitiu a identificação de 133 MOVs das classes orgânicas polares e apolares como os compostos emitidos por esses animais quando eles se encontram saudáveis. Além disso, com o objetivo de demostrar e testar a eficiência da análise, a cerumenolômica foi aplicada para o diagnóstico de intoxicação bovina por Stryphnodendron spp., uma árvore comum no Pantanal e no Cerrado brasileiro. A cerumenolômica demostrou alta eficiência na descriminação das amostras intoxicadas e não intoxicadas usando dois biomarcadores: 9-Tetradecen-1-ol e 2-Octildecanol. Em resumo, o método cerumenolômico descrito aqui surge como uma ferramenta em potencial para ser aplicado em medicina veterinária.Item Comparação de técnicas de extração e caracterização de ácidos naftênicos em águas produzidas(Universidade Federal de Goiás, 2022-04-27) Vieira, Michel Moreira de Freitas; Vaz, Boniek Gontijo; http://lattes.cnpq.br/7814534710550639; Vaz, Boniek Gontijo; Coltro, Wendell Karlos Tomazelli; Santos, Jandyson MachadoIn the first part of the work, for the purpose of studying the extraction efficiency of NAs in Brazilian PWs, some SPE methodologies were studied for these analytes, established in the literature, in order to perform the comparison and determination of the best methodologies, in order to optimize and adapt them to the analytes of the Brazilian scenario. The stationary phases studied in this first part were: C18, ENV, ENV+, Strata-X and HLB. We proceeded with the extractions by fully replicating the parameters as presented in the literature, in order to be able to compare the solid phase extraction methodologies employed to the same matrix. The analyses were performed on the Q-Exactive Orbitrap ultra-high resolution mass spectrometer, using the electrospray ionization (ESI) source in negative mode. Data processing was performed with Composer and Thanus software. The results obtained indicate that the methodologies of group III, with the solid phases ENV and HLB, showed the highest number of AN species extracted with the three solvents used, hexane (HEX), dichloromethane (DCM) and isopropanol (IPA). The results obtained indicate that the solvent DCM extracted in higher concentrations species with a DBE value of 1, and the solvent methanol extracted in higher concentrations species with a DBE value of 2. Moreover, the solvent hexane presented species with a DBE value of 2 in high concentrations, indicating that these species are eluted by this solvent with greater efficiency. Finally, tests with methodologies using ENV, C18, APS, Strata-X and HLB solid phases were performed in order to determine the optimum solvent volume and optimum sample pH for efficient extraction. The results presented indicate that pH 2 showed the highest recovery results for acidic species. Also, the extractions eluted with 20 mL of dichloromethane, divided into two fractions provided better results in terms of the number of formulas assigned. Another point of note is the fact that acid species were eluted by water during the washing step for the removal of salts from the PW sample, making it necessary to remove this step from the extraction methodologies