Indiana University-Purdue University Indianapolis (IUPUI) / Gas Chromatography/Mass Spectrometry (GC/MS) is an analytical technique that sees frequent use in labs across the world. It is also one of the most common instruments found in forensic science laboratories. This technique can efficiently and accurately separate and identify a broad range of compounds that may be present in evidence submitted for analysis. In this work, the versatility of this instrument was applied to new methodologies for the detection of explosives and illicit drugs. The analysis of explosives by GC/MS is common but can be problematic. The thermally sensitive nature of some explosives can cause them to degrade when introduced to the high temperatures of a GC/MS inlet. This project looked at the design and implementation of a way to separate and detect a variety of nitrate ester explosives in a short amount of time. In addition to this, a new technique known as Total Vaporization-Solid Phase Microextraction (TV-SPME) was utilized as a pre concentration technique. The parameters for TV-SPME were statistically optimized for a low level of detection. The combination of these areas allowed for the separation of ethylene glycol dinitrate, nitroglycerin, erythritol tetranitrate, and pentaerythritol tetranitrate with a detection limit as low as 50 parts per trillion (ppt). Degradation products such as 1-mononitroglycerin, 1-3-dinitroglycerin, and 2-mononitroglycerin were also successfully identified. The problem of thermally labile compounds extends to the world of illicit drugs. In the second project, several derivatization schemes were developed for common controlled substances. N,O-Bis(trimethylsilyl)trifluoroacetamide (BSTFA) with 1% trimethylchlorosilane (TMCS) was used for silylation, trifluoroacetic anhydride (TFAA) was sued for acylation, and (N,N-Dimethylformamide dimethyl acetal (DMF-DMA) for alkylation. Three different compound classes totaling 15 different drugs were investigated. N,N-Dimethylformamide dimethyl acetal (DMF-DMA) is presented as a novel way of derivatizing several drugs of interest. Primary amines and zwitterions were derivatized with this reagent to much success, specifically: amphetamine, 2-(4-Iodo-2,5-dimethoxyphenyl)ethan-1-amine (2C-I), pregabalin, and gabapentin.

The first section of this dissertation (Chapter I-III) describes the development of new methodologies to prepare uracil and arylidenehydantoin derivatives. A regioselective synthesis of 6-alkyl- and 6-aryluracils was developed by the dimerization of 3-alkyl- and 3-aryl-2-propynamides promoted by either Cs2CO3 or K3PO4. A range of 3-aryl-2- propynamides, with both electron-deficient and electron-rich 3-aryl substituents, were successfully reacted in high yields. A synthetic route to prepare arylidenehydantoins was developed using the Pd-catalyzed dimerization of 3-aryl-2-propynamides. Both electron rich and electron deficient 3-aryl-2-propynamides were dimerized successfully to produce the desired arylidenehydantoins in moderate to excellent yields. The second section of this dissertation (Chapter IV and V) describes the development of a reliable low-cost method to determine amounts of xylitol in sugar free gum samples to predict dangerous exposure levels for dogs. Xylitol is generally considered safe for human consumption and is frequently used in sugar free gum, however, it is extremely toxic to dogs. It is unknown if partially consumed chewing gum is also dangerous. A method to determine xylitol content of these sugar free gum samples employing GC-MS with direct aqueous injection (DAI) is presented. This method was successfully applied to over 120 samples including, fresh gum, 5 min, 15 min, and 30 min chewed gum samples. Further extension of this work resulted in the development of an undergraduate laboratory experiment for upper-level undergraduate chemistry students which teaches calibration methods, xylitol extraction, sample preparation for GC-MS analysis, and data analysis.

Widespread sedentary lifestyle and unhealthy eating habits in the last few decades have resulted in a dramatic increase of the number of people affected by obesity, type 2 diabetes, and cardiovascular diseases. The study of these pathological conditions revealed that impaired metabolism often causes these disorders. Lipid metabolism research has contributed significantly to determining mechanisms underlying metabolic disorders. Omega-3 fatty acids are an interesting target for lipidomics studies because they were shown to lower risk of cardiovascular diseases and are hypothesized to regulate lipid metabolism. In this work, I optimized lipid extraction and chemical modification methods for analysis of fatty acids profile of tissue samples and biofluids using comprehensive two-dimensional gas chromatography coupled to mass spectrometry (GCxGC-MS). At first, I evaluated the relative amount of omega-3 fatty acids in red blood cells (Omega-3 index) of people living in Czech Republic in either the capital city (n=476) or the rural region (n=388). For this large-scale project, I extracted phospholipids from red blood cell (RBC) membranes, transesterified them into fatty acid methyl esters (FAMEs), and measured their profile by GCxGC-MS. The mean Omega-3 index was 3.56 mol % and I detected no significant...

Highly oxygenated compounds in bio-oil produce negative properties that have hampered fuel development. Copyrolysis with plastics has increased hydrogen content in past research. Py-GC/MS analyses for two wood types (pine and oak) and three plastic types (polystyrene, polypropylene and high density polyethylene) established temperature, heating rate and residence time to produce a typical bio-oil. Analysis of various plastics to wood ratios by Py-GC/MS showed that a 50:50 wt/wt ratio produced the highest level of low molecular weight compounds best for fuel viscosity. Copyrolysis was performed on a laboratory-scale reactor at these temperature and wood-to-plastic ratios. Copyrolysis lowered bio-oil oxygen content and increased carbon content. Lower water content, acid value and viscosity also resulted, improving bio-oil suitability for fuels. Cross reactions between wood and plastics formed no new chemical species during copyrolysis. These results indicate that copyrolysis of waste plastics with woody biomass has potential for improving bio-oil properties for fuels production.

Vine tea (Ampelopsis grossedentata) is a Chinese herbal tea, rich in the natural antioxidant dihydromyricetin, that has multiple health properties and potential food and beverage applications. However, there is little information available on vine tea aroma, color and sensory characteristics. In this study, volatile components of vine tea infusions were identified by headspace solid-phase micro-extraction (HS-SPME) and gas chromatography-mass spectrometry (GC-MS). Commercial vine teas samples were brewed with distilled water and Blacksburg (VA, USA) tap water and analyzed in triplicate. Vine tea infusions had acidic pH values and dark, reddish-yellow color. Type of water and vine tea sample both affected the overall volatile chemical composition of vine tea infusions. A total of fifty-six volatile components were identified in vine tea infusions. However, only seven aldehydes (hexanal, (E)-2-hexenal, (Z)-4-heptenal, nonanal, (E,Z)-2,4-heptadienal, (E,E)-2,4-heptadienal, and β-cyclocitral), two ketones (6-methyl-5-hepten-2-one and β-ionone), and one alcohol (1-penten-3-ol) were identified in more than 90% of all vine tea infusions (n=54). Results of this study may help further investigations in chemical and sensorial characteristics of vine tea, and the development of new healthy products. / Master of Science in Life Sciences

Natural steroid estrogens such as 17beta-estradiol in low nanogram per liter concentrations can adversely affect the reproductive health of aquatic organisms. The overall goal of this research was to quantify the sorption of 17beta-estradiol to three soils considered to be agriculturally productive from different physiographic regions in Virginia to aid in modeling the concentration of estrogens available for transport in runoff from agricultural fields. Batch equilibrium experiments were conducted with various concentrations of 17beta-estradiol (E2) in a background solution of 5 mM calcium chloride and 100 mg/L sodium azide added to four separate soil samples representative of productive agricultural soils from three different physiographic regions of Virginia. Groseclose loam, Myatt sandy loam and Cecil loam were supplied by the Crop and Soil Environmental Sciences Department at Virginia Tech. All soils were collected from the plow layer (0 to 15 cm) except for an additional Cecil soil sample from the Bt horizon. The concentration of E2 in the liquid phase was measured by gas chromatography/mass spectrometry (GC/MS) and was used to find the time to reach equilibrium and to develop sorption isotherms for each soil. The time required to reach equilibrium for all soils was less than 24 hours. A linear isotherm provided the best fit to model the sorption of E2 to Cecil and Myatt soils (R2 = 0.94 and 0.96, respectively). For Groseclose soil, the general form of the Freundlich isotherm fit best (R2 = 0.98), although the linear isotherm also provided a good fit (R2 = 0.93). The sorption of E2 to agricultural soil appears to be related to the organic carbon content of each soil (Pearson coefficient, 0.82). Attempts to analyze and create isotherms for conjugated E2 by deconjugating with metholysis were unsuccessful. / Master of Science

Processos metabólicos naturais no organismo humano levam à formação de substâncias como compostos orgânicos voláteis (VOCs), de modo que, em um quadro patológico, processos diferenciados podem ocorrer nas células, fazendo com que um conjunto diferente de compostos seja produzido. Com esta hipótese, VOCs podem ser analisados em amostras biológicas com a intenção de se verificar alterações em seus perfis que sejam indicativos de certas patologias. No presente estudo, foi selecionado o suor como matriz, amostra de coleta simples e não-invasiva, de composição menos complexa e relacionada aos níveis sanguíneos e emanações da pele. Adicionalmente, foram também analisadas amostras de urina, para obtenção de dados comparativos. O presente estudo compreendeu amostras de voluntários saudáveis (grupo controle-C) e com diagnóstico de câncer confirmado (grupo positivo- P). As amostras de suor foram coletadas com o dispositivo PharmChek®, após, o patch foi removido, inserido em frasco e os VOCs isolados com emprego de técnica otimizada de Headspace estático (HS). Para as amostras de urina, estas foram analisadas com e sem tratamento por ?-glucuronidase. Perfis de VOCs foram obtidos por análise por cromatografia gasosa acoplada a espectrometria de massas (GC-MS) para todas amostras. A tentativa de identificação dos compostos detectados foi feita por busca na biblioteca NIST08 e uso do software AMDIS32. Diferenças qualitativas (teste chi-quadrado, p<<0,01) e quantitativas (teste U de Mann-Whitney, p<<0,01) foram avaliadas entre os perfis do grupo controle e positivo. Para o suor foram selecionados os potenciais biomarcadores pentanal, hexanal, heptanal, octanal, limoneno, 2-etil-1-hexanol, 1-undeceno, fenol, 2,6-dimetil-7-octen-2-ol (DMOL), nonanal, decanal e tridecano; para a urina, fenol e DMOL, hidrólise-dependentes, foram selecionados. Método HS-GC-FID (acoplado a detector por ionização de chama) foi desenvolvido e validado segundo a RDC 27/2012 da ANVISA, para ambas amostras. No suor, os analitos apresentaram limites inferiores de quantificação (LIQ) de 1 ng/adesivo, 5 ng/adesivo para o fenol; na urina foram de 2 ng mL-1 para o DMOL e 10 ng mL-1 para o fenol. Linearidade foi observada para faixa de 2 a 150 ng/adesivo e, 2 e 5 a 400 ng mL-1 na urina. No suor, a precisão variou de 0,08 a 12,35% e os analitos foram demonstrados estáveis para os ensaios realizados. Curvas ROC (Receiver Operating Characteristic) foram avaliadas e áreas sob a curva foram todas próximas a 1, com valores cut-off de 1,71 a 35,44 ng/adesivo no suor e 8,71 e 52,86 ng mL-1 na urina. 2-etil-1-hexanol se demonstrou negativamente correlacionado com o estágio clínico em adenocarcinomas (rô= -0,527) e DMOL, no suor, e aldeídos C5-C8 positivamente relacionados ao estágio do câncer de próstata (rô= 0,779 e 0,684, respectivamente). Conclui-se, portanto, que o método apresentado se mostrou eficiente, contudo, prático e de baixo custo, e os resultados obtidos corroboram para ideia da determinação de VOCs como promissora ferramenta auxiliar de diagnóstico no câncer. / Natural metabolic processes in the human body lead to the formation of substances such as volatile organic compounds (VOCs), so that, in a pathological context, differentiated processes can occur in the cells, causing a different set of compounds to be produced. With this hypothesis, VOCs can be analyzed in biological samples with the intention to verify changes in their profiles that are indicative of certain pathologies. In the present study, sweat was selected as the matrix, due simple and non-invasive collection, with lower complexity composition and related to blood levels and skin emanations. In addition, urine samples were also analyzed to obtain comparative data. The present study comprised samples from healthy volunteers (control-C group) and individuals with confirmed cancer diagnosis (positive-P group). The sweat samples were collected with PharmChek® device, next, the patch was removed, inserted in a vial and the VOCs were isolated using an optimized Static Headspace (HS) technique. For urine samples, these were analyzed with and without ?-glucuronidase treatment. VOC profiles were obtained by gas chromatography coupled to mass spectrometry (GC-MS) for all samples. The attempt to identify the detected compounds was made by searching the NIST08 library and using the AMDIS32 software. Qualitative differences (chi-square test, p << 0.01) and quantitative tests (Mann-Whitney U test, p << 0.01) were evaluated between the profiles of the control and positive groups. For the sweat, the potential biomarkers pentanal, hexanal, heptanal, octanal, limonene, 2-ethyl-1-hexanol, 1-undecene, phenol, 2,6-dimethyl-7-octen-2-ol (DMOL), nonanal, decanal and tridecane; for urine, phenol and DMOL, both hydrolysis-dependent, were selected. HS-GC-FID (coupled to flame ionization detector) method was developed and validated according to RDC 27/2012- ANVISA, for both samples. In sweat, the analytes presented limits of quantification (LOQ) of 1 ng/patch, 5 ng/patch for phenol; in urine were 2 ng mL-1 for DMOL and 10 ng mL-1 for phenol. Linearity was observed for the range of 2 to 150 ng/patch and, 2 and 5 to 400 ng mL-1 in urine. In sweat, the precision ranged from 0.08 to 12.35% and the analytes were shown to be stable for the assays performed. Receiver Operating Characteristic (ROC) curves were evaluated and areas under the curve were all near to 1, with cut-off values of 1.71 to 35.44 ng/patch in sweat and 8.71 and 52.86 ng mL-1 in urine. 2-ethyl-1-hexanol was shown to be negatively correlated with the clinical stage in adenocarcinomas (rho= -0.527) and DMOL, in sweat, and C5-C8 aldehydes sum, positively related to the stage of prostate cancer (rho= 0.779 and 0.684, respectively). It was concluded, therefore, that the method presented proved to be efficient, however, practical and low cost, and the results corroborate to the idea of VOCs determination as a promising diagnostic tool for cancer diagnosis.

Desde os primórdios da civilização o homem utiliza substâncias que causam modificações na percepção da realidade e também por vivenciar sensações prazerosas promovidas por estas. O abuso de drogas consiste em um padrão de utilização onde o indivíduo começa a sofrer prejuízos físicos, psicológicos, legais ou sociais e consiste em um problema de saúde pública de nível mundial. Para a presente pesquisa, foi desenvolvido um método de análise que utiliza a microextração dispersiva líquido-líquido (DLLME) e a cromatografia em fase gasosa acoplada à espectrometria de massas (GC-MS) para a pesquisa de drogas e metabólitos em amostras de urina de pacientes em tratamento pelo Centro de Atenção Psicossocial em Álcool e Drogas (CAPS-AD) de Ribeirão Preto. As substâncias que foram analisadas são a anfetamina, metanfetamina, metilenodioxianfetamina (MDA), metilenodioximetanfetamina (MDMA), metilenodioxietilanfetamina (MDEA), anidroecgonina metil éster (AEME), cocaína, cocaetileno, benzoilecgonina, codeína, morfina, heroína e 6-monoacetilmorfina. Para a extração dos analitos das amostras de urina foram estabelecidas e validadas as seguintes condições: utilização de 3,0 mL de urina; mistura de solventes composta por 150 ?L de clorofórmio (solvente extrator) e 1400 ?L de isopropanol (solvente dispersor), 2,0 mL de tampão fosfato de sódio 0,2 M pH 10,3 ± 0,5 para a manutenção do pH das amostras e 100 ng dos padrões internos: anfetamina-D11, MDMA-D5, cocaína-D3 e heroína-D9. O extrato resultante foi evaporado, ressuspendido em acetato de etila e derivatizado utilizando N-Metil-N-(trimetilsilil) trifluoroacetamida (MSTFA) sob aquecimento a 60° C durante 30 min. O método analítico desenvolvido e validado apresentou: seletividade; linearidade na faixa de 10-400 ng/mL para todos os analitos, exceto a AEME, onde a faixa linear foi de 50-300 ng/mL; os coeficientes de correlação linear (r) de todos os analitos foram superiores a 0,99; a precisão e a exatidão ficaram dentro do intervalo preconizado pelos guias de validação utilizados; não foi observado efeito residual; as amostras apresentaram estabilidade de curta duração, estabilidade após ciclos de congelamento e descongelamento e estabilidade pós-processamento. Foram coletadas 117 amostras de urina dos pacientes em tratamento pelo CAPS-AD de Ribeirão Preto. A análise por GC-MS confirmou a presença de cocaínicos em 75% das amostras analisadas (positividade 60% maior em comparação aos testes preliminares). Destas, 51% apresentaram o marcador AEME, que indica o uso da cocaína em base livre (crack) e 52% apresentaram o marcador cocaetileno, que indica o uso concomitante de álcool. Não foram encontrados resultados positivos para os analitos anfetamínicos e opióides. Face aos resultados obtidos, podemos concluir que a técnica de extração otimizada e o método analítico desenvolvido são adequados e de uso promissor para a identificação e quantificação simultânea de drogas de abuso e seus principais metabólitos em amostras de urina. / Since the dawn of civilization man has used substances that cause changes in perception of reality and also to experience pleasurable sensations promoted by them. Drug abuse is a pattern of use where the individual begins to suffer physical, psychological, legal or social damage and consists of a public health problem worldwide. To this research, was developed a method which uses dispersive liquid-liquid microextraction (DLLME) technique and gas chromatography analysis coupled to mass spectrometry (GC-MS) for the detection of drugs and metabolites in urine samples of patients in treatment by Psychosocial Care Center on Alcohol and Drugs (CAPS-AD) in Ribeirão Preto. Substances that have been analyzed are amphetamine, methamphetamine, methylenedioxyamphetamine (MDA), methylenedioxymethamphetamine (MDMA), methylendioxyethylamphetamine (MDEA), methyl ester anidroecgonine (AEME), cocaine, cocaethylene, benzoylecgonine, codeine, morphine, heroin and 6-monoacetylmorphine. For the analyte extraction from urine samples, the following conditions were established and validated: use of 3.0 mL of urine; solvent mixture composed of 150 uL of chloroform (extractor solvent) and 1400 uL isopropanol (dispersing solvent), 2.0 ml of 0.2 M sodium phosphate buffer pH 10.3 ± 0.5 for the pH samples maintenance and 100 ng of internal standards: amphetamine-D11, MDMA-D5, cocaine-D3 and heroin-D9. The resulting extract was evaporated, resuspended in ethyl acetate and derivatized using N-Methyl-N- (trimethylsilyl) trifluoroacetamide (MSTFA) under heating at 60° C for 30 min. The developed and validated analytical method presented: selectivity; linearity in the range of 10-400 ng/ml for all analytes except AEME, where the linear range was 50-300 ng/ml; the linear correlation coefficients (r) of all analytes were greater than 0.99; precision and accuracy were within the recommended range used for validation guides; residual effect was not observed; the samples showed a short-term stability, stability after cycles of freezing and thawing and post-processing stability. We collected 117 urine samples from patients treated by CAPS-AD of Ribeirão Preto. The GC-MS confirmed the presence of cocainics in 75 % of the samples (positivity 60% higher compared to preliminary tests). Of these, 51% had the AEME marker, indicating the use of cocaine free base (crack) and 52% have the cocaethylene marker, indicating the concomitant use of alcohol. No positive results for amphetamines and opioids analytes were found. Considering our results, we conclude that the extraction technique and the analytical method developed are suitable and promising use for simultaneous identification and quantification of drugs of abuse and its main metabolites in urine samples.

Os alcaloides ß-carbolinas, Harmina e Harmalina, e o potente alucinógeno N, N-dimetiltriptamina são os principais componentes da Ayahuasca, uma bebida típica, utilizada na forma de chá e amplamente empregada em rituais religiosos na América do Sul. Embora seu uso ocorra desde períodos pré-colombianos ainda são poucas as informações sobre suas possíveis aplicações clínicas, assim como seus efeitos toxicológicos. Nos últimos anos, o uso da Ayahuasca se difundiu para vários países: Estados Unidos, Alemanha, Inglaterra, França e Espanha, com isso houve o aumento do interesse em estudos científicos acerca do chá. Em decorrência do aumento no consumo do chá, é importante o desenvolvimento e aplicação de métodos analíticos validados na rotina laboratorial e a utilização de uma matriz biológica que seja de fácil coleta e possibilite um número representativo de amostras. No presente trabalho, o suor foi utilizado como uma amostra biológica não convencional, pois possui algumas vantagens em relação às amostras convencionais como, por exemplo, o sangue; possui uma coleta não invasiva, indolor e sem constrangimentos para o voluntário, fácil aquisição de um registro cumulativo da exposição de substâncias, e janela de detecção mais longa, tornando-se uma ferramenta útil, pois permite a realização de uma coleta com maior frequência e sem atrapalhar o ritual religioso do voluntário. Embora vários métodos já tenham sido publicados para determinação de diferentes substâncias utilizando o suor como matriz biológica, tais como: ecstasy, cocaína, anfetamina, codeína, MDMA e ?9-Tetrahidrocannabinol, até a presente data, não foram encontrados métodos descritos na literatura utilizando o suor como matriz biológica para identificação de DMT, HRM e HRL em voluntários usuários da bebida. O método desenvolvido apresentou linearidade de 50 a 1500 ng/adesivo e o limite de detecção encontrado foi de 15 ng/adesivo para Harmina, 15 ng/adesivo para Harmalina e 10 ng/adesivo para o DMT. O ceficiente de variação intra-ensaio variou de 3,92% a 9,06% e o inter-ensaio variou entre 3,34% a 9,85%; a exatidão variou entre 87,5% a 105%. A recuperação encontrada foi superior a 70%. / The ß carbolines alkaloids, and Harmina Harmalina, and the potent hallucinogen N, N - dimethyltryptamine are the main components of Ayahuasca, a typical drink used in tea form widely used in religious rituals in South America. Although its use occurs from preoperative - Colombians are still little information about their possible clinical applications, as well as their toxicological effects. In recent years, the use of Ayahuasca has spread to many countries: United States, Germany, England, France and Spain, it was the increased interest in scientific studies about tea. Due to the increase in the consumption of tea, it is important the development and application of validated analytical methods for routine monitoring and the use of a biological matrix that is easily collected and allow a representative number of samples. In the present work , sweat was used as a biological sample unconventional because it has some advantages as compared to conventional samples, such as blood; have a non-invasive, painless and without constraints for voluntary, easy acquisition of a cumulative record of exposure of substances, and longer detection window, making it a useful tool collects as it allows the realization of a collection more frequently and without disturbing the religious ritual of voluntary. Although several methods have been published for the determination of different substances using sweat as a biological matrix, such as ecstasy, cocaine, amphetamine, codeine, MDMA and ?9 - Tetrahidrocannabinol, to date, no methods have been described in the literature using the sweat as a biological matrix for identification of DMT, HRL and HRM in volunteer users of the drink. The developed method was linear 50-1500 ng / patch and the limit of detection was 15 ng / patch Harmina, 15 ng / patch Harmalina and 10 ng / patch for DMT. The ceficiente intra -assay variation ranged from 3.92 % to 9.06 % and inter -assay ranged from 3.34 % to 9.85%; the accuracy ranged from 87.5 % to 105 %. The recovery was found to exceed 70%.

A constante preocupação com o aumento do uso de agrotóxicos nas lavouras e os riscos gerados pelos resíduos destes compostos fazem com que os órgãos responsáveis pela fiscalização de alimentos no Brasil controlem a presença dessas substâncias nos produtos que chegam à mesa do consumidor. Atualmente, um dos grandes problemas na produção de alimentos é a utilização de substâncias proibidas em lavouras, muitas das quais não possuem estudos nem limites máximos de resíduos (LMR) estabelecidos, assim como a utilização de substâncias já registradas, mas em quantidades ou métodos de manejo incorretos. Ambos os casos podem resultar em sérios problemas à saúde humana. O objetivo deste estudo foi a avaliação da determinação de morfolina em amostras de manga utilizando técnicas como a Extração em Fase Sólida e a Cromatografia Gasosa acoplada à Espectrometria de Massas (SPE-GC-MS), assim como a Microextração em Sorvente Empacotado e Cromatografia Gasosa acoplada à Espectrometria de Massas (MEPS-GC-MS). Um segundo objetivo deste estudo consistiu em desenvolver, validar e avaliar uma metodologia analítica capaz de identificar quantitativamente a morfolina em amostras de manga por Cromatografia Líquida de Ultra Eficiência acoplada a Espectrometria de Massas em tandem (UHPLC-MS/MS). Para análise por GC-MS fez-se necessária a etapa de derivatização do analito, de forma que o mesmo aumentasse sua volatilidade e diminuísse a polaridade. A comparação entre as técnicas SPE e MEPS não foi possível devido ao efeito de matriz causado pela contaminação do liner e da coluna cromatográfica. Já a metodologia validada por UHPLC-MS/MS seguiu os critérios exigidos pelo Manual de Garantia da Qualidade Analítica, do Ministério da Agricultura Pecuária e Abastecimento (MAPA). O método foi aplicado em mangas de diferentes variedades obtidas no comércio local. Não foram encontrados resíduos de morfolina em nenhuma das amostras investigadas, de acordo com a metodologia proposta. Os resultados apresentados neste trabalho estabelecem metodologias eficientes, rápidas e de baixo custo na determinação de morfolina em amostras de manga. / The recurrent increasing of the use of pesticides on crops and the consequent risks due the exposure to chemical residues have urged the food regulation agencies to control the levels of these substances in products that reach consumer\'s table. A major problem nowadays for the production of food is the use of banned substances in crops and the extrapolation of the limit dosages of substances, which may result in serious problems to human health. Furthermore, many of these substances commonly used in crops still lack substantial information about the maximum residue levels (MRLs). The aim of this study was the evaluation of morpholine levels in mango samples using distinct techniques such as Solid Phase Extraction followed by Gas Chromatography coupled to Mass Spectrometry (SPE-GC-MS) and Microextraction by Packed Sorbent followed by Gas Chromatography Mass Spectrometry (MEPS-GC-MS). Another main goal of this work is the development, validation and evaluation of an analytical methodology to identify and quantitfy the presence of morpholine in mango samples, using Ultra-High Performance Liquid Chromatography coupled to tandem Mass Spectrometry (UHPLC-MS/MS). For the analysis of samples by GC-MS, it was required an initial step of derivatization of the analyte, in order to increase its volatility and reduce polarity. The comparison between SPE and MEPS techniques could not be performed due to matrix effects caused by contamination of the liner and the chromatographic column. On the other hand, the validated methodology for UHPLC-MS/MS presented herein followed all requirements proposed by the Analytical Quality Assurance Manual, accordingly to the Ministry of Agriculture, Livestock and Food Supply from Brazil. This method was applied in mango sample belonging to a wide variety of species found in the city of São Carlos, SP. Nevertheless, no significant levels of morpholine residues were found in any of the samples. In this work, we established a methodology efficient, fast and low cost for the determination of morpholine in mangos.