Mestrado em Química
URI Permanente para esta coleção
Nível: Mestrado Acadêmico
Ano de início: 2006
Conceito atual na CAPES: 5
Ato normativo: Homologação da 85ª Reunião do CTC-ES, Parecer CNE/CES nº 163/2005.
Processo nº 23001.000081/2005-56 do Ministério da Educação.
Publicado no DOU 28/07/2005, seção 1, página 11)
Periodicidade de seleção: Anual
Área(s) de concentração: Química
Url do curso: https://quimica.vitoria.ufes.br/pt-br/pos-graduacao/PPGQ/detalhes-do-curso?id=954
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- ItemÁcidos graxos e compostos fenólicos como substâncias fitotóxicas nos resíduos agroindustriais: vinhaça, torta de filtro e bagaço(Universidade Federal do Espírito Santo, 2018-02-16) Luz, Dandara Alves; Gomes, Anne Caroline Candido; Kuster, Ricardo Machado; Cunha Neto, Álvaro; Santos, Roberto PereiraThe residues of agroindustry from sugar cane vinasse, filter cake and bagasse are abundant in Brazil, a leading country in the production of sugar and alcohol. The use of this waste solves problems related to waste and environmental pollution. Extracts were produced by solvent maceration, some of them were submitted to liquid / liquid partitions and others were saponified, resulting in numerous samples that were tested for phytotoxic activity and analyzed by GC-MS, by ESI (-) FT-ICR-MS and ESI (-) MS / MS leading to the identification of 22 substances, among them ten fatty acids and twelve phenolic compounds. The DIC experiments of the pseudomolecular ions [MH] –327,21796 (C18H32O5) and 329,23355 (C18H34O5) led to the proposition of the polyhydroxylated unsaturated fatty acids, 9,12,13-trihydroxy-10,15-octadecadienoic, for the first and the isomers 9 , 12,13-trihydroxy-10-octadecenoic acid / 9,10,13-trihydroxy-12-octadecenoic acid for the second, which have not been described so far in Saccharumssp. GC-MS analyzes corroborated the chemical profile already observed by the FT-ICR-MS technique. In the phytotoxicity bioassay in Lactuca sativa, the most active fractions were the dichloromethane partition of vinasse (IC50 = 168.4 ppm) and ethyl acetate of vinasse (IC50 = 262.3 ppm). The FT-ICR-MS and CG-EM analyzes demonstrated that the VDiCl sample consists of a proportionally similar mixture of fatty acids and phenolic acids, whereas VAcOEt is formed in a higher proportion by a mixture of phenolic compounds. In the bioassays with Ipomoea purpurea(weed), the dichloromethane partition of vinasse was also more active, inhibiting root growth by 52% (IC 50 = 344 ppm). At the same concentration, the ethyl acetate partition inhibited only 25.74% root growth. It has been suggested that the interaction between fatty acids and phenolic compounds is important for a higher rate of inhibition and that the presence of oxilipins (polyhydroxylated unsaturated fatty acids)is essential for the more marked phytotoxicity of this sample. This work demonstrated the potentiality of fatty acids and phenolic compounds present in the agroindustrial residues regarding phytotoxicity, indicating that these can be used as raw materials in the elaboration of innovative products for the control of weeds, minimizing the risks that the incorrect disposal to the environment.
- ItemAdequação e verificação de procedimentos para determinação de mercúrio em amostras de fígado e rim de rato utilizando a técnica CV-GF AAS(Universidade Federal do Espírito Santo, 2014-08-24) Santos, André Eliziário dos; Jesus, Honério Coutinho de; Athayde, Geisamanda Pedrini Brandão; Barthus, Rosangela Cristina; Ribeiro, Araceli Veronica Flores NardyMercury is an element that still needs constant monitoring because it is highly toxic at trace-level concentrations, with possibility exposure and contamination by a variety of forms present in the environment. Thus, the aim of this work was adapt and verify a simple and efficient procedure for mercury determination in Wistar rat tissues using cold vapor generation, pre-concentration in graphite furnace and analysis by atomic absorption spectrometry (CV-GF AAS). They were made comparison of amalgamation methods, procedure optimization, verification of merit figures and analysis of liver and kidneys of chronically treated rat. The best results were obtained using the hot block digestion method as sample pre-treatment and gold coated tube combined with and net of gold for amalgamation. It was necessary to use dichromate, isopropanol and simeticone pre-analysis. Procedure accuracy was verified through recovery tests at five concentration (between 92 and 114 %), enabling the use of the proposed procedure.
- ItemAdulteração de óleo diesel e determinação do tamanho de gota de emulsões(Universidade Federal do Espírito Santo, 2016-03-09) Cunha, Danyelle Alves da; Barbosa, Lúcio Leonel; Lacerda Júnior, Valdemar; Pasa, Vanya Marcia DuarteCrude oil canbe defined as a complex mixture of hydrocarbons and compounds containing S, O, N, and metals in its composition. During the production process occurs the formation of water in oil emulsions (W / O) or oil in water (O / W). These types of emulsions are harmful since they increase viscosity, reduce drainage rate and can promote the precipitation of paraffin crystals and asphaltene aggregates. Precipitation of these compounds interferes the production lines, since they are deposited in the tubing, decreasing its inner diameter and increasing production costs. The industry requires oil free of water to reduce the risks of corrosion and, consequently, reduced manufacturing costs. Therefore, the monitoring of such systems by determining the droplet size distribution (DTG) is indispensable. From the refining of crude oil, are obtained derived petroleum products such as LPG (cooking gas), kerosene, gasoline, diesel oil, among others. The diesel oil is a middle distillate, since the boiling point varies between 125ºC and 328ºC. This distillate has utmost importance as a fuel in the Brazilian road transport, leading the ranking of fuel consumption in the road sector in Brazil. Thus, the adulteration of this fuel is crescent and areadded, to this oil, products such as kerosene, biodiesel and residual oils, since they have good miscibility. Among the most widely used techniques for the study of this oil there is the infrared spectroscopy, mass spectrometry and nuclear magnetic resonance (NMR) High resolution. However, studies involving diesel adulteration by Low field -NMR hadnot been publishedyet. This study aims to verify by low field-NMR adulteration of diesel and also to determine the droplet size of emulsions water / diesel and water / biodiesel
- ItemAlcaloides isoquinolínicos e atividade citotóxica in vitro de Hippeastrum canastrense J. Dutilh & R. S. Oliveira (Amaryllidaceae)(Universidade Federal do Espírito Santo, 2016-10-24) Vicente, Andressa Reis; Borges, Warley de Souza; Fronza, Márcio; Lima, Murilo Marinho de Castro; Kuster, Ricardo MachadoThe Amaryllidaceae family lies between the 20most applied plant families as therapeutic agents against various diseases.An important characteristic of this family is the presence of a unique group of alkaloids, exhibitingseverals biological activities such as antitumor, antibacterial, antifungal, antimalarial,antiviral, analgesic, and antiparasiticand acetylcholinesteraseinhibition. This work presents a chemical study of the alkaloidscontent found in the bulbs and flowerlystems of Hippeastrum canastrense, an endemic species from Brazilthat notably has no studies concerning it’s chemicals components so far. In addition,the investigation of the cytotoxicityeffects of the extracts and alkaloidsisolatedwere carried out with tumor cells assays. Therefore, a classical acid-base extraction of methanol extracts of both parts of H. canastrensewas performed, followed by chromatographic separation techniques in order to isolate the alkaloids present in the species.The GC-MS analysis was ableto identify 40 alkaloids, and 16 well-known alkaloidswere isolated: sanguinine(1), hippeastrine(4), candimine(5), 7-methoxy-O-methyllycorenine(7), albomaculine(8), homolycorine(9), lycorine(10), 8-O-demethylhomolycorine(13), norpluviine(14), 2a,7-dimethoxyhomolycorine(15), 2a-hydroxihomolycorine(16), 2a-hydroxialbomaculine(17), masonine(18), normasonine(19), nerinine(20), e trisphaeridine(21), and yet five novel alkaloids here reported as 8-O-demethyl-2a-hydroxihomolycorine(2), 7-methoxymasonine(3), 2-O-metthylcandimine(6), 7-methoxynormasonine(11) e 2a-methoxyhomolycorine(12).Thecrudeextracts and enriched extracts, as well as the compounds 1, 3, 4, 5, 6, 7, 8, 10, 11, 12, 13, 15, 18, 19e 20 were evaluated for their cytotoxicity in normal fibroblast-cells and also for breast, liver and panceas tumor-cells.The alkaloids hippeastrine, candimine and lycorine showedsignificantcytotoxic effect in all assays. The lowest IC50values for hippeastrine and candimine were obtained for human pancreatic carcinoma cells, while for lycorine was in hepatocelluar carcinoma cells assays.The crude extracts of Hippeastrum canastrenseshowed remarkable cytotoxicity in tumor cells especially in hepatocellular carcinoma cells. The ethyl acetate alkaloids-enriched extracts from the flowerly stems and bulbs, along with the hexane extract from bulbs expressed a relevant cytotoxic potencial in tumor cells. However, bulbs extracts appears to be most selective then the extracts of flowerly stems
- ItemAlcaloides isoquinolínicos isolados das partes aéreas de Worsleya procera (Lem.) Traub (Amaryllidaceae)(Universidade Federal do Espírito Santo, 2016-10-24) Moraes, Carolina Torres; Borges, Warley de Souza; Cunha Neto, ÁlvaroMany natural compounds have shown interesting biological and pharmacological activities and are considered important targets and one of the largest sources of new drugs, used directly or indirectly as a starting point for developing new drugs. Of plant compounds with biological potency, the alkaloids present in the Amaryllidaceae family are especially effective, for example, the alkaloid galanthamine, a selective, reversible and competitive inhibitor of the enzyme acetylcholinesterase and is marketed for the treatment of Alzheimer's disease. No study of chemical and biological characterization of the plant Worsleya procera(Lem.)Traub (Amaryllidaceae) was found in the literature and thus, for the purpose of phytochemical characterization of this plant, various chromatographic techniques were used in their extracts for the isolation and identification of alkaloids. As a result, 19 alkaloids and a mixture of two epimers alkaloids (18and 19)were isolatedfrom the aerial parts of W. procera: 3-epimacronine (1),albomaculine (2), lycorine (3), galanthine (4), tazettine (5), hippeastrine (6), O-methyllycorenine (7), 7-methoxy-O-methyllycorenina (8), homolycorine (9), 8-O-demethylhomolycorine (10), trisphaeridine (11), haemanthamine (12), 8-O-demethyl-O-methyllycorenine (13), ismine (14), 6-O-methylpretazettine (15), pretazettine (16), alkaloidwith skeleton type haemanthamine(17), haemanthidine (18), 6-epihaemanthidine (19), 8-O-demethyl-2a-hydroxyhomolycorine (20) e N-fomylismine (21), where their structures could be elucidated by the 1H NMR technique one-and two-dimensional, in compared with literature data. The alkaloid 8-O-demethyl-2a-hydroxyhomolycorineis reported for the first time from natural source.Nineisolated alkaloids(Tazettine, 3-epimacronine, albomaculine, lycorine, galanthine,hippeastrine, O-methyllycorenine, 7-methoxy-O-methyllycorenina and 8-O-demethylhomolycorine) were evaluated for antimicrobial activity, with all weak activity when compared to posivito control.The GC-MS technique proved to be a rapid and efficient technical alkaloids identification, since the analysis results of W.proceraplantextractsfound that the majority were alkaloids 22with skeleton homolicorina type, skeleton lycorinetype and skeletontazetina type, which was confirmed by the total mass of alkaloid obtained
- ItemAnálise de metodologias de ensino de Química para debater a temática biodiesel à luz do enfoque CTSA : alfabetização científica no ensino médio(Universidade Federal do Espírito Santo, 2012-11-12) Silva, Marcio Corrêa da; Lacerda Júnior, Valdemar; Silva, Elias Meira da; Leite, Sidnei Quezada Meireles; Silva Filho, Luiz Carlos daThis work had as one of its objectives to evaluate how the Biodiesel inserted in the teaching of Chemistry could be used as a generator theme within the study of the environmental area for fifteen students enrolled in a federal institution high school and for forty students enrolled, also in high school at a private school, from February to July 2011, both located in Vitória, Espírito Santo. It can be seen through a theoretical basis and through the reflection of current Chemistry teaching in the classroom, on generator themes arguing about an active and transformative environmental education. The use of Chemistry is seen by many authors as the cause of environmental impacts such as pollution, poisons, insecticides, preservatives, additives and pesticides. However, you can also use these teachings to awaken the spirit of awareness on the students of their role as educated citizens active in the search for environment preservation. Based on several authors as Loureiro (2005) and Guimarães (2004), Guimarães and Vasconcellos (2006), Saito (2002) and Leff (2001), we have attempted to discuss the generator themes, postulated by Freire (2005, 2007), to contextualize the importance of studying the environment. A qualitative study was undertaken from the perspective of an active search. The data evaluation consisted of the analysis of the answers given by students from the questionnaires answered by them before and after the methodological approaches appropriate to the theme of Biodiesel. The questionnaires contained questions consisting of various items related to the students knowledge of Biodiesel in addition to questions that allowed the evaluation of these students regarding their understanding with respect to the easiness and difficulties found by them in relation to Chemistry. We conclude that through the analysis of the data, which is not only possible, but necessary that the school create mechanisms so that their teachers come to develop activities related to the generator themes
- ItemAnálise de Parafinas por APCI-FT-ICR MS : Uma Análise Rápida e Simples na Identificação de Hidrocarbonetos Saturados, Cíclicos e Poliaromáticos(Universidade Federal do Espírito Santo, 2014-12-01) Tose, Lilian Valadares; Romão, Wanderson; Vaz, Boniek GontijoThe analysis of hydrocarbon using atmospheric or ambient ionization techniques still remains a challenge in mass spectrometry. Traditionally, the ionization occurs via protonation or deprotonation. The molecules of interest must have a basic or acidic group to generated [M + H]+ or [M - H]- ions. To overcome such limitation, it is proposed a simple, easy, fast and powerful analytical methodology to ionize saturated (linear and branched), unsaturated, and cyclic hydrocarbons as well as polyaromatic and heteroaromatic hydrocarbonsby atmospheric pressure chemical ionization (APCI) using small hydrocarbons as reagents in a FT-ICR mass spectrometer. These molecules may be present in hydrocarbon fraction samples and paraffin/crude oil blends. Among the APCI hydrocarbon reagents studied, isooctane provided the best results when compared to pentane, hexane, cyclohexane and heptane. The method renders the ionization of hydrocarbons to yield [M – H]+ ions with no associated fragmentation using nitrogen as sheath gas.
- ItemAnálise de petróleo por espectroscopia de impedância eletroquímica e da corrosão do aço AISI 1005 em soluções contendo íons sulfeto(Universidade Federal do Espírito Santo, 2011-02-11) Perini, Nickson; Freitas, Marcos Benedito José Geraldo de; Souza, Ernesto Chaves Pereira de; Castro, Eustaquio Vinicius Ribeiro deThe electrochemical impedance spectroscopy is technique that allowtomonitoring ofcrude oil, blends,emulsions, and the interaction between these multiphase fluids and steel, allowing the evaluation of corrosion resistance. Crude oils are dielectric and has low conductivity. Therefore it is difficult to conduct measurements in conventional electrochemical cells with three electrodes, which under these conditionsrequired the use of only two parallel electrodes and validation of the impedance measurements. The behavior of the blends and crudeoil is framed for the characterization in the Nyquist diagram for a homogeneous distribution in constant relaxationtime, represented by undistorted semicircle in high frequency. At low frequencies, presents a distorted semicircle assigned to the interface metal/oil. The Nyquist diagram for water in oil emulsions showstwo semicircles in high and medium frequency attributed, respectively, to oil phase and emulsion. The thirddistorted semicircle at low frequency indicates the value of the corrosion resistance of carbon steel in contact with the emulsion. Multivariate analysis (PCA) is used to correlate oil properties with the values obtained by equivalent circuit of the impedance spectra. The corrosion of carbon steel, followed by film formation in aqueous solutions containing H2S in low concentration, is measured by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), SEM, XRD and Mossbauer. The films of iron sulfide formed under these conditions are corrosive and it increases the rate of corrosion. In CV are detected two peaks of anodic current density, attributed to film formation of iron sulfide and its subsequent oxidation. The irregular and compact morphology was observed by SEM and the composition of the film by EDX, with the majority consisting of Fe, S and O. The crystalline phases were detected by XRD, containing Mackenawite, Marcasite, Pyrite,Troilite, iron hydroxide and hydrate iron sulfate. The effect Mossbauer characterization indicatedthat the film is 85,3% as FeS2, mainly Pyrite. The impedance of the films in solution0.1 mol.L-1Na2SO4reveals that the films of iron sulfide formed under these conditions are corrosive and it increases the rate of corrosion
- ItemAnálise de pimenta-do-reino por espectrometria atômica: diferentes abordagens(Universidade Federal do Espírito Santo, 2018-02-19) Krause, Maiara; Lima, Maria Tereza Weitzel Dias Carneiro; Lima, Inobert de Melo; Athayde, Geisamanda Pedrini BrandãoThe present study was divided into two chapters. First, it was determined the concentrations of the elements Cd, Co, Cu, Fe, Mn, Mo, Ni, Pb, Se, Ti, V and Zn black pepper samples marketed in the State of Espírito Santo. The samples underwent an acidic decomposition procedure assisted by microwave radiation. The Fe and Zn elements were determined by flame atomic absorption spectrometry (F AAS), while the others were determined using the inductively coupled plasma mass spectrometry (ICP-MS) technique. The accuracy of the procedures was evaluated through the analysis of the certified reference material Agro C1003a of tomato leaf. The values measured using the methodology adopted in this study and the certified values did not present significant difference, when Student's t-test with 95% confidence level was applied. After verification of accuracy, the analysis methodology wasapplied to 50 commercial pepper samples. For each manufacturer, denominated as A, B, C, D and E, 5 grain samples and 5 ground samples were obtained to verify a possible supply of trace elements during the processing of the black pepper. Each of the samples was chosen from a different lot, in order to obtain a greater variability of the set of samples that are commercialized in the region. The results show that two of the five analyzed brands showed a great increase in the concentrations of Fe, Pb and V after grinding, suggesting that the increase in the concentration of these elements can be influenced by the milling process. Moreover, for samples where there was a significant increase in Pb, it exceeded safe limits for human consumption according to Brazilian legislation, which is 200 µg kg-1. In the second part of the work a simple and fast methodology for the determination of Pb in pepper samples was developed. The developed method consisted in the use of suspension sampling together with the technique of atomic absorption spectrometry with atomization in graphite furnace. The preparation stage of the suspensions was optimized applying experiment planning. Parameters such as pyrolysis and atomization temperatures, calibration and the necessity of use chemical modifiers were evaluated. The analysis methodology presented simplicity and speed in it experimental stages, and provided low limits of detection and quantification. The method also showed good accuracy and allowed the calibration by aqueous standards. The methodology adopted is presented as an alternative to the traditional procedures of analysis and can be considered adequate for routine analyzes, it also can be extended to other trace elements present in black pepper
- ItemAnálise de resíduo de disparo de armas de fogo utilizando ICP-MS: caracterização de munições limpas(Universidade Federal do Espírito Santo, 2016-09-29) Costa, Rayana Alvarenga; Romão, Wanderson; Lima, Maria Tereza Weitzel Dias Carneiro; Athayde, GeisamandaPedrini Brandão; Aquije, Glória Maria de Farias ViegasGiven the strong relationship between the crimes of murder and the use of firearms in Brazil, Forensic Ballistics is an important tool to detect waste generated by shooting firearms (GSR -gunshot residues) in the hands of a suspect , helping to determine the authorship of a shot. Among the types of ammunition, clean ammunition was developed in the last decade to minimize exposure of the shooters to lead (Pb), as in conventional ammunition, this element and the Ba and Sb present significativas1 concentrations. Studies show difficulties in GSR detection clean ammunition by energy dispersive spectroscopy coupled with scanning electron microscopy (SEM / EDS) and residuográfico test, thus modern analytical techniques such as mass spectrometry with inductively coupled plasma (ICP-MS) has being used as a quick analysis for the detection of chemical elements present in GSR, since a high sensitivity, selectivity and multielement character. Thus, the objective of this study was to evaluate the applicability of ICP-MS technique to quantify the GSR coming from clean ammunition (from the English "clean range ammunition") using caliber .40 pistol and .38 depending on the number of shots (n = 1-7 and n = 1-5). The GSR were collected in the regions of the clamp-palmar and dorsal clamp and evaluated on both hands (right and left). The results were compared with classic techniques in forensic ballistics: colorimetric assay using sodium rhodizonate (residuográfico) and SEM / EDS. Negative results were observed for Pb and Ba using residuográfico test for GSR analysis clean ammunition shots to 7. The analysis by SEM / EDS was performed on the GSR produced from n = 7 (.40 caliber pistol) and n = 5 (.38 revolver) of clean ammunition. Photomicrographs showed that the GSR produced from clean ammunition presents no defined as the morphology of conventional ammunition GSR. In addition, EDS results of the particularly identified elements as C, O, K, Al, S, Si, Cu, Zn, Ti, Cr, Cl, Mo, Sr and Fe. Unlike convencionas methods, ICP-MS technique showed positive results for Pb, Ba and Sb with maximum concentration of 2.64 µg·L-1(± 0.60) 10.9 µg·L-1(± 5.44) and 0.119 µg·L-1(± 0.02) to40 pistoland 4.59 µg·L-1(± 1.8), 1.95 µg·L-1(± 1.1) 0.099 µg·L-1(± 0.07 ) to .38 revolver. Besides them, elements such as Al, Ti, Cr, Mo, Cu, Zn and Sr were also detected in the clean ammunition GSR. It was observed that with increasing number of shots was in the concentration of all investigated elements and suggested that Al, Sr, Zn and Cu may be used as markers for new GSR clean ammunition. Therefore, the ICP-MS technique showed promising results and proved adequate for GSR analysis of clean ammunition.
- ItemAnálise de resíduos de disparos de armas de fogo (GSR) usando ICP OES : desenvolvimento de uma nova metodologia analítica(Universidade Federal do Espírito Santo, 2014-01-01) Vanini, Gabriela; Romão, Wanderson; Lima, Maria Tereza Weitzel Dias Carneiro; França, Hildegardo Seibert; Bruns, Roy EdwardViolence involving firearms is a big issue in the state of Espírito Santo and the development of new methods and techniques that can help the police to elucidate homicides is extremely important to the reduction of crime. Optical emission spectrometry with inductively coupled plasma (ICP OES) stands out as a highly sensitive, versatile and cheap technique when compared to current techniques used by the police. Therefore, the objective of this work was to develop a fast, sensitive and reliable method for collection and quantification of gunshot residues (GSR) using ICP OES to determine the concentrations of lead (Pb), barium (Ba) and antimony (Sb) released by .38 caliber handgun and .380 and .40 caliber pistols. The work was divided into three chapters. In the first, it was discussed the optimization step of the ICP OES technique for GSR, which evaluated the operating parameters of radio frequency power, nebulizer gas flow rate and aspiration rate, using multivariate central composite design. In the second chapter, a study was conducted using Taurus® .38 handgun, which investigated the best residue collection region of the hand in men and women, the feasibility of different collectors for GSR , the comparison of the colorimetric analysis and ICP OES technique for varying distances and the influence of hand washing before and after shots. The results showed that the regions of the thumb and forefinger palm, and the back of the thumb and forefinger are the best collection areas. The pure swab showed better results in terms of cost / benefit and it is possible to obtain concentrations of the metals of interest even with hand washing of shooter. In the third chapter a comparative study between .38 handgun and .380 and .40 pistols it was done. It was quantified Pb, Ba and Sb on the right and left hands of the shooters for the three weapons and held a prediction of the number of shots through the construction of a calibration curve. It was noted the amount of GRS found on the weapons, follows the order .38 handgun>.380 pistol> .40 pistol. Overall results showed important information in GSR analysis, representing a breakthrough in forensic investigations.
- ItemAnálise do teor e da qualidade dos lipídeos presentes em sementes de oleaginosas por RMN de baixo campo(Universidade Federal do Espírito Santo, 2013-02-27) Constantino, André Fazolo; Santos, Reginaldo Bezerra dos; Lacerda Júnior, Valdemar; Liao, Luciano Morais; Freitas, Jair Carlos Checon deIn order to choose from the variety of oleaginous plants for biodiesel production, the oil content of several matrices was determined through different experiments of low-field 1H Nuclear Magnetic Ressonance (NMR) with varied pulse sequences, namely single pulse, spin-echo, CPMG and CWFP (Continuous Wave Free Precession). The experiments applying the first three sequences showed high correlation with each other and with the solvent extraction method. The best results were achieved through CPMG experiments. When the CWFP sequence was used, the correlation with the solvent extraction method was very low and the results were not compatible with those employing the other sequences. Quality of the vegetable oils was also evaluated. The study was based on the existing correlation between the T2 values of the oils obtained through 1H NMR signals achieved through CPMG and their properties, such as viscosity, iodine index and cetane index. These analyses were carried out using HCA and PCA chemometric tools. The results were significant enough to separate the oleaginous matrices according to their quality. The signals achieved using the CWFP and CP-CWFP (Carr-Purcell - Continuous Wave Free Precession) sequences were also used in the chemometric analyses. However, the study identified that the signals generated from these sequences depend both on T1 and T2. Therefore except for the most viscous oleaginous matrices, in HCA and PCA analyses, the matrices were not grouped according to their qualities. The experiments carried out through CP-CWFP were even more advantageous than those through CWFP because the former had higher signal amplitude variation in the quasi steady state (QSS). Thus, using the most adequate pulse sequence, the low-field 1H NMR technique was confirmed as an important tool to help selecting oleaginous matrices for biodiesel production.
- ItemAnálises de padrões isoméricos de canabinóides e produtos de Cannabis por GC-MS, GCxGC-qMS e UPLC acoplado a espectrometria de massas de mobilidade iônica (TWIM-MS)(Universidade Federal do Espírito Santo, 2018-02-15) Santos, Nayara Araújo dos; Vaz, Boniek Gontijo; Romão, Wanderson; Ortiz, Rafael Scorsatto; Kuster, Ricardo MachadoCannabissativaL. plant, popularly known as marijuana, is considered a complex matrix due to its many constituents, among them more than 100 are classified as cannabinoids. These compounds are distributed in the plant in different isomeric forms, which hinders the unambiguous characterization of the psychoactive compounds. Therefore, the present study reported the analysis of seven cannabinoid standards (five neutral: ?9-THC, CBD, CBC, CBN and CBG,and two cannabinoid acid standards: ?9-THCA A and CBDA), as well asCannabisproducts (hashish and marijuana) and parts of theCannabisplant (flower andleaf) using four different analytical techniques, mono and two-dimensional gas chromatography (GC-MS and GCxGC-qMS), Ultra performance liquid chromatography coupled to mass spectrometry (UPLC-ESI(±)TOF-MS) and ion mobility spectrometry (UPLC-ESI(±)-TWIM MS). The results obtained by GC-MS demonstrated extremely close retention times (?t=1.303 min) in the five cannabinoids analyzed from the use of a non-polar stationary phase, DB5. However, GCxGC-qMS resulted in a better distinction in the identification of cannabinoids constitutional isomers, where four of eleven cannabinoids were detected in the three samples; hashish, flower andCannabisleaf. The analysis, by UPLC-ESI(±)TOF-MS, of marijuana and hashish samples, allowed the identification of eight isomers in the XIC mode at m/z315.2354. In the analyzes by UPLC-ESI(-)TWIM MS, a largenumberof compounds was mainly detected for hashish and flower samples. Asfor cannabinoidsofm/z357, ten peaks could be detected,equally distributed, in flower and hashish chromatograms. Although GC is one of the most used techniques in the study of cannabinoids inCannabisand its products, it does not allow the identification of acid cannabinoids, which are widely available in the plant, without previous laborious preparatory stages. Differently, liquid chromatography combined with ion mobility mass spectrometry, allowed the identification of both types of cannabinoids (acids and neutrals), in addition to providing a greater detection of constitutional isomers compounds compared to classical GC technique
- ItemAplicabilidade da eletrocoagulação, eletrocoagulação seguida de reativo de fenton e eletrofenton no tratamento de lixiviado de aterro sanitário(Universidade Federal do Espírito Santo, 2010-04-14) Lima, Claudia Maria Russo de; Borges, Raquel Machado; Jesus, Honerio Coutinho de; Schneider, Edgar; Freitas, Marcos Benedito José Geraldo de; Dias, Mauro CesarThis work aimed to study processes of electrochemical treatment applied in a sanitary landfill leachate, with the investigation of physical and chemical parameters of interest and its better operation conditions. The following systems were studied: electrocoagulation, electrocoagulation followed by the Fenton ´s reagent and eletroFenton. Leachates from the landfill in the municipality of Aracruz (Espírito Santo) were used in the research, collected in 2008 and 2009. The samples were sent to the Laboratory of Analytical Chemistry, Federal University of Espirito Santo, and preserved in refrigerator. An electrochemical reactor was constructed using a 3L beaker, mechanical agitation, and electrodes of carbon steel 1020 plates, coupled to a 9 A source of constant direct current. Several experiments were performed for studies of electrocoagulation in order to determine the best operation, with changes in the structural parameters (electrode geometry) and operational (temperature, electrolyte volume and polarity reversal). For the tests of electrocoagulation followed by Fenton ´s reagent, it has changed the relationship between the quantities of ferrous sulfate heptahydrate and hydrogen peroxide, using the ratio of 1:17 and 1:25 of the salt with hydrogen peroxide. For eletroFenton tests were also conducted tests on the change in relationship, but in amounts of 1:20 and 1:25. As result of this research, it was observed that the electrolytic process and this in combination with advanced oxidation process are indicated for the treatment of landfill leachate generated from municipal solid waste. The initial characterization of leachate (pH, organic matter, ammonia nitrogen, chloride and metals) indicated that it comes from landfill over the age of 2 years with a degree of stabilization of the landfill in the acidogenic phase. The electrocoagulation, electrocoagulation followed by Fenton's reagent and eletroFenton shown to be adequate for the process of removing color, turbidity, organic compounds and metals, but not suitable for removal of ammonia and particulate matter. Better results were obtained by combining the electrolytic process with the oxidative, and the treatment eletroFenton showed better results in general, combined with a treatment period shorter (30 minutes). We obtained a removal efficiency of COD between 40 and 50% in electrocoagulation, 60 to 70% in electrocoagulation followed by Fenton, and up to 78% in eletroFenton system. The results of this study are of great importance as support for project development of physical-chemical treatments on an industrial scale for the treatment of leachate from landfill
- ItemAplicação da espectrometria de massas ambiente por Paper Spray Ionization na identificação e quantificação de cocaína e no controle de qualidade de bebidas(Universidade Federal do Espírito Santo, 2016-12-09) Tosato, Flávia; Romão, Wanderson; Pelição, Fabrício Souza; Filgueiras, Paulo RobertoRapid, inexpensive and efficient analyzes are required for laboratory routines, especially when applied in forensic chemistry. Uses of the environment sources allow the analyzes to be direct and fast. Thus, they are innovative options to improve sensitivity and selectivity. In this work, a methodology was developed using environmental mass spectrometry by paper spray ionization mass spectrometry (PS-MS) for different data matrices: (i) to identify and quantify cocaine and its adulterants from PS-coupled chromatography -MS; (Ii) discriminate or classify ten Brazilian beer brands in pilsen and lager; And (iii) to identify the controlled counterfeit of whiskey with cachaça in order to quantify the volume of cachaça added in the mixture. In the analysis of cocaine and adulterants, the standards were identified in the CCD and analyzed by PS-MS, and a calibration curve was optimized. The beer was previously fractionated using the solid phase extraction (SPE) methodology with water / methanol and the four extracts were characterized in positive ionization mode, PS (+) MS. For both cases, 20 µL of the analyte was applied to the PS-MS paper surface. In the quantification of cachaça in blends of whisk-cachaça. The results indicate that the use of Cdc coupled to PS-MS allows the identification of cocaine and its adulterants. A good linearity for the curves was found (cocaine (R2 = 0.9989), benzocaine, (R2 = 0.9934) Caffeine (R2 = 0.9988), phenacetin (R2 = 0.9966), and lidocaine (R2 = 0.9987)) and LOD lower than that of the CCD technique. For the beer samples the signs of sugars stand out over the other groups, and after extraction with water / methanol it was possible to distinguish the spectra of the different beer brands and classify them in pilsen and lager bythe PCA technique. Using PS (±) -MS and PLS with variable selection it was possible to estimate quantitatively the cachaça content mixed with whiskey. With this, the use of environmental sources, such as PS, is effective for identification of several matrices, facilitating routine analyzes
- ItemAplicação de ICP-MS e ICP OES no estudo do perfil inorgânico de amostras de cocaína de rua(Universidade Federal do Espírito Santo, 2015-04-27) Amorim, Zanata Brandão; Athayde, Geisamanda Pedrini Brandão; Lima, Maria Tereza Weitzel Dias Carneiro; Pacheco, Wagner FellipeThe abusive use of drugs has become a global problem that has serious consequences for both drug users and society. Determining the inorganic constituents of illicit drugs can be used to indicate the quality (the purity and concentration of other constituents of the drugs). Variations in drug purity can be used to formulate hypotheses about the structure of the illegal drug market in terms of differences in distribution and delivery. Fifty two street cocaine samples that were seized in different regions of the Espírito Santo State of Brazil were analysed. The sample pretreatment consisted of digesting 0.1 g of a sample with 6 mL 5% v/v HNO3 in a microwave closed-vessel system after diluting the sample to a 15mL volume. Inductively coupled plasma optical emission spectrometry (ICP OES) or inductively coupled plasma mass spectrometry (ICP-MS) were then used to determine the concentrations of Al, Ca, Cu, Fe, Mn, Mg, Zn, Mo, Co, Pb and P in these samples. The accuracy of the procedures was verified using recovery tests at two concentrations (50 and 100 µg L-1 ). The resulting data were then statistically analysed. Using Hierarchical Cluster Analysis (HCA) was possible differentiation of the seizure Regions. Pearson correlations allowed to correlate the elemental concentrations with the chemicals compounds that are used in the production and adulteration of cocaine. Boxplot analysis confirmed the distinction of the seizure regions.
- ItemAplicação de RMN de baixo campo para estimar características físicas e químicas de água de produção da indústria de petróleo(Universidade Federal do Espírito Santo, 2016-08-29) Machado, Maiara Pereira; Barbosa, Lúcio Leonel; Conalgo, Luiz Alberto; Athayde, Geisamanda Pedrini BrandãoThe composition of the produced water is varied and depend on the characteristics and depth of the oil production field. Among the constituents are some paramagnetic ions such as Co, Cr, Cu, Fe in small concentrations. Paramagnetic ions interact strongly with the solvent, causing appreciable reduction in the transverse relaxation time (T2).In this work applied to nuclear magnetic resonance (NMR) in the time domain with the aid of inductively coupled plasma optical emission spectrometry (ICP OES) to estimate the concentration of paramagnetic ions Co2+, Cr3+, Cu2+, Fe3+, Mn2+and Ni2+in aqueous solution and water in oil produced.The results for the aqueous medium showed that the low field enables a good correlation with ICP OES, giving a linear correlation between the transverse relaxation rate (T2-1) and the emission intensity for the range of concentration from 0.5 to 10 mg.L-1,concluding that the transverse relaxation rate can be used as a "probe" optical emission, which has advantages such as reduced costs, faster analyzes and not destructiveness of the sample.Since the produced water analysis led to reduction in T2values from 1.09 to 0.14s. They determined the concentrations of ions by ICP OES and noted the existence of a correlation with the concentration and T2, however it was not possible to estimate the concentration of these ions in the water.From T2study of produced water was correlated with some chemical-physical characteristics as salinity, conductivity, and pH. reasonable correlations were obtained from T2to the salinity and the natural logarithm of T2 with pH.
- ItemAplicações da espectrometria de massas de resssonância ciclotrônica de íons por transfromada de Fourier (FT-ICR MS) em petroleômica(Universidade Federal do Espírito Santo, 2013-08-23) Pereira, Thieres Magaive Costa; Cunha Neto, Alvaro; Vaz, Boniek Gontijo; Lopes, Rosana CardosoPetroleum is a complex mixture, being one of the most challenging mixtures for chemical analyzes. Many techniques are employed to characterize constituents of the oil. However , when we combine the highest resolving power and accuracy of mass spectrometry , especially Ion Cyclotron Resonance Fourier Transform ( FT - ICR MS ) with sources of atmospheric pressure ionization , an assignment need more than 20 000 organic compounds in the oil can be obtained. In the oil industry there is a great interest in the analysis of asphaltenes and naphthenic acids due to problems such as corrosion and deposit formation, which increases production costs. Therefore this study aims to evaluate the thermodegradation of naphthenic acids, besides the use of sources of ESI, APCI, APPI, MALDI and LDI for the acquisition of new data on the characterization of asphaltenes . Two test oils were used in thermodegradation of the oil with an acidity of 2.38 mg KOH g -1 and Oil B with 4.79 mg KOH g- 1 which were treated at 280 , 300 and 350 ° C for a period of 2 , 4 and 6 hours. Generally, the major classes identified for both samples O2, NO2, and C, respectively. A slight reduction of NAT and relative abundance refers to the class O2 were observed as a function of temperature and aging time (T = 280 ? 300 ° C t = 2 ? 6 h), and the heat treatment temperature at 350 ° C showed a determinant for the removal of class O2. The chemical asphaltenes Brazilian samples was evaluated using five different methods of ionization in both modes of ionization: positive and negative, then the molecular weight distribution, distribution class, typical plots versus carbon number and DBE van Krevelen diagrams were obtained and discussed. An unusual behavior was observed for the LDI and MALDI source ( ± ) FT - ICR MS . A comprehensive profile of m / z 500-3000, with spacing of 24 Da was observed, and this corresponds to allotropes of fullerene C60. In general, the asphaltenes had an heteroatómicas high proportion of species such as HC , HC [ H] , N, [ H] , N2O N2O [ H] N2, N2 [ M ] O O [ H] to mode (+) and N, [ H ] , NO [ H] , NO , NO2, [ H] , N2O N2O [ H ] for the negative mode . In the diagrams DBE against the carbon number , the asphaltenes shown for each value of DBE composed of a small amplitude with respect to NC, thus providing images that form a line of 45 ° between the axes CN and DBE. This indicates that these compounds do not exhibit large chain alkyl, composed mainly of aromatic rings. In general diagrams van Krevelen showed a high proportion of compounds ratio H / C ~ 0.7, confirming the existence of highly aromatic species
- Item"Atribuição inequívoca dos sinais de RMN e da estereoquímica relativa de compostos rígidos tipo 'gaiola' (cage-like) : estudo experimental e teórico"(Universidade Federal do Espírito Santo, 2009-09-18) Salles, Roberta Chechetto; Lacerda Junior, Valdemar; Cunha Neto, Álvaro; Camara, Celso de Amorim; Santos, Reginaldo Bezerra dosIn this work the Nuclear Magnetic Ressonance (NMR) technique was used for the unequivocal attribution of the 1H and 13C{1H} NMR signals from one-dimensional (1H NMR, 13C NMR and DEPT-135) and bidimensional (COSY, HMBC, HSQC and NOESY) experiments. The six analyzed compounds were tricyclo[6.2.1.02,7]undeca-4,9-diene-3,6-dione (3), tricyclo[6.2.1.02,7]undec-9-eno-3,6-dione (20), rel- (6S)-6-hidroxytricyclo[6.2.1.02,7]undec-9-en-3-one (21), rel-(1R, 6S, 7R, 2S, 8S)-3-Oxo-6-(3,4,5-trimethoxyfenilcarbonnyloxi)tricyclo[6.2.1.02,7]undec-9-ene (22), rel-(1S, 2S, 6S, 8S, 7R, 9R)-6,9-epoxytricyclo[6.2.1.02,7]undecan-3-one (23), rel- (2S, 4S, 6S, 10S, 1R, 9R)-10-bromine-6,9-epoxitricyclo[6.2.1.02,7]undecan-3-one (24) were obtained from the adduct obtained from the Diels-Alder reaction between cyclopentadiene and p-benzoquinone. This study focused on cage-like compounds which are known for being biologically active, being amantadine the first and most known bioactive cage-like compound. All chemical shift values were attributed despite the difficulty found due to signals overlapping. When possible, the spin-spin coupling constants (J) were also attributed. The distinction between the bridge hydrogens, for the majority of the compounds, was done by the analysis of the 2D NOESY NMR spectrum. The data obtained from the experimental attribution of the 1H and 13C NMR chemical shift and spin-spin coupling values (J) were compared with theoretical data obtained from computational calculations. The mean deviation (MD), standard deviation (SD) and the linear correlation coefficient (R) values were analyzed for the endo and exo adducts in order to evaluate if the B3LYP/cc-pVTZ model presented good results in shielding tensors (d) and spin-spin coupling constants (J) calculations. Analyzing the results obtained from the theoretical calculations it was observed that, for the chemical shift values the model used presented good results, however, for the calculations of the coupling constants the model did not present satisfactory results
- ItemAvaliação da Biodistribuição de mercúrio em roedores após exposição crônica(Universidade Federal do Espírito Santo, 2016-10-31) Gomes, Mariana Zanotelli; Santos, Leonardo dos; Carneiro, Maria Tereza Weitzel Dias; Saint’Pierre, Tatiana Dillenburg; Athayde, Geisamanda Pedrini BrandãoMercury needs to be constantly monitoring due to of its toxic characteristics in concentrations at trace levels, leading to various disorders in the kidney, respiratory tract and in the central nervous system and diseases such as Alzheimer and Parkinson. The present study describes the mercury biodistribution in rat blood and organs (heart, brain, kidney, liver and testicle) after chronic administration of mercury chloride (HgCl2). The animals where divided into three experimental groups: 6 control (CT) treated with NaCl; 7 treated with 2.172 µg.kg-1 of HgCl2 (G1) and 7 treated with 21.72 µg.kg-1 of HgCl2 (G2). After 30 days, the rats were killed, and blood and organs were collected. For the microwave assisted decomposition, about 0.1 g of sample was weighed into a Teflon tube, to which were added: 1 mL 30% v/v H2O2; 6 mL of ultra-pure H2O and 1 mL of concentrated HNO3. For determination of mercury in the blood, 200 µL of blood was added in a 15 mL polypropylene tube and diluted with 0.005% w/ v Triton-X in 0.5% v/v 10 mL nitric acid (dilution was 1 + 49). The mercury was determined by inductively couples plasma mass spectrometry (ICP-MS), obtaining limit of detection (LOD) and limit of quantification (LOQ) of 6.0 ng.L-1 and 10.0 µg.kg -1 , respectively. Regarding the organs, for group G1, the kidney Hg concentration was 302.0 ± 45.1 µg.kg-1 , the remaining ones were below LOD. For the G2 group heart, brain and testicles being the organs with the lowest concentrations of mercury: 15.6 ± 4.6; 13.9 ± 2.0 and 15.8 ± 2.4 µg.kg -1 , respectively. The liver had a mercury concentration of 25.5 ± 7.7 µg.kg -1 and the kidney was the target organ, whose concentration was 2818 ± 1586 µg.kg -1 . The concentration of mercury found in blood in groups G1 and G2 were respectively: 3.8 ± 0.6 µg.kg -1 and 4.3 ± 0.5 µg.kg -1 . The results indicate that mercury is preferentially concentrated in the kidneys and liver and is not available in the blood.