Determinação de biomarcadores geoquímicos em ambiente anóxico da Lagoa da Conceição (SC)

Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro de Ciências Físicas e Matemáticas. Programa de Pós-Graduação em QuímicaBiomarcadores geoquímicos e composição elementar foram avaliados a fim de determinar as fontes de matéria orgânica (MO) em um ambiente anóxico da Lagoa da Conceição. Um testemunho e três amostras de sedimentos superficiais (0-5 cm) foram coletados e analisados, após fracionamento e derivatização quando necessário, por cromatografia à gás com detector por ionização em chama (GC-FID) e cromatografia à gás acoplada a espectrometria de massas (GC/MS). Biomarcadores geoquímicos como alcanos, álcoois, ácidos graxos e esteróis foram detectados nas amostras de sedimentos superficiais e testemunho. Em ambos os casos, a razão C/N associada à distribuição dos homólogos para cada classe de biomarcadores permitiu inferir que a MO sedimentar é constituída de uma mistura de origens, como: plantas terrestres, detritos de bactérias e, principalmente, algas. A análise de agrupamento hierárquico permitiu agrupar as frações do perfil sedimentar quanto ao efeito do processo de eutrofização e a mudança das fontes de MO nos diversos intervalos de profundidade do testemunho. Para as amostras de sedimentos superficiais, a análise de agrupamento hierárquico possibilitou avaliar a dissimilaridade entre amostras provenientes de coletas realizadas em períodos diferentes. Além da origem da MO sedimentar, a alteração diagenética mediada por bactérias foi avaliada por meio das razões de esteróis saturados/insaturados. Os resultados obtidos neste trabalho estão de acordo com a condição redox e com os parâmetros físico-químicos apresentados pelo ambiente nos períodos de coleta.Geochemical biomarkers and the elemental composition were evaluated to determine the sources of organic matter (OM) in an anoxic environment region of Conceição Lagoon (SC). A core and three samples of surface sediments (0-5 cm) were collected and analyzed, after fractionation and derivatization when necessary, by GC-FID and GC/MS. Geochemical biomarkers as hydrocarbons, alkanols, fatty acids and sterols were detected in the surface sediment samples and along the core. In both cases, the C/N ratio associated with the distribution of homologs of each class of biomarkers allowed us to infer that the sedimentary OM consists of a mixture of sources, such as terrestrial plants, bacterial debris and algae. Based on the hierarchical analysis the effect of the process of eutrophication and changing sources of OM in the various depth intervals of the core were evaluated. For samples of surface sediments, the hierarchical cluster analysis allowed us to evaluate the dissimilarity between samples collected from different periods. In addition to the origin of the sedimentary OM, the bacterially mediated diagenetic alteration was assessed by means of the ratios of sterols saturated/unsaturated. The results of this study are consistent with redox conditions and physico-chemical parameters provided by the environment in the collection periods

Desenvolvimento de metodologia eletroanalítica para determinação de penicilinas utilizando eletrodo de cobre

TCC (graduação) - Universidade Federal de Santa Catarina, Centro de Ciências Físicas e Matemáticas, Curso de Química.O efeito complexante dos antibióticos β-lactâmicos frente ao íon cobre (II) possibilitou a utilização do eletrodo metálico para a determinação destas espécies em amostras farmacêuticas. Para o desenvolvimento da metodologia, foram estudadas as condições experimentais com a finalidade de conseguir melhores resultados, assim como os parâmetros intrínsecos de cada técnica utilizada. Os resultados obtidos sugerem que o método proposto responde de maneira eficiente na determinação de formulações farmacêuticas, oferecendo limites de detecção e quantificação dentro da faixa necessária. Entretanto, o método responde de maneira semelhante para os dois fármacos estudados

Quantification Of Sterol And Triterpenol Biomarkers In Sediments Of The Cananeia-iguape Estuarine-lagoonal System (brazil)

Sterols and triterpenols present in sedimentary cores from 12 stations along the Cananeia-Iguape estuarine-lagoonal system were investigated by ultra-high performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS). Ten sterols and three triterpenols were identified and quantified, indicating both natural and anthropogenic sources. The relative distributions of sterol and triterpenol showed that the study area is submitted to organic matter (OM) from the Ribeira de Iguape River, seawater, surrounding vegetation, and plankton production. The contribution of these sources depends on the region of the estuarine-lagoonal system and the depth of sediment. Regarding anthropogenic sources, only the samples submitted to freshwater flow from the Ribeira de Iguape River presented concentration of coprostanol higher than the threshold value and diagnostic ratios, coprostanol/(coprostanol + cholestanol) and coprostanol/cholesterol, that indicate moderate contamination by domestic sewage in that area of the estuarine-lagoonal system. Therefore, the approach used herein identified the OM sources and its transport along the Cananeia-Iguape estuarine-lagoonal system (Brazil), which is a complex of lagoonal channels located in a United Nations Educational, Scientific and Cultural Organization (UNESCO) Biosphere Reserve

Quantification of Sterol and Triterpenol Biomarkers in Sediments of the Cananéia-Iguape Estuarine-Lagoonal System (Brazil) by UHPLC-MS/MS

Sterols and triterpenols present in sedimentary cores from 12 stations along the Cananéia-Iguape estuarine-lagoonal system were investigated by ultra-high performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS). Ten sterols and three triterpenols were identified and quantified, indicating both natural and anthropogenic sources. The relative distributions of sterol and triterpenol showed that the study area is submitted to organic matter (OM) from the Ribeira de Iguape River, seawater, surrounding vegetation, and plankton production. The contribution of these sources depends on the region of the estuarine-lagoonal system and the depth of sediment. Regarding anthropogenic sources, only the samples submitted to freshwater flow from the Ribeira de Iguape River presented concentration of coprostanol higher than the threshold value and diagnostic ratios, coprostanol/(coprostanol + cholestanol) and coprostanol/cholesterol, that indicate moderate contamination by domestic sewage in that area of the estuarine-lagoonal system. Therefore, the approach used herein identified the OM sources and its transport along the Cananéia-Iguape estuarine-lagoonal system (Brazil), which is a complex of lagoonal channels located in a United Nations Educational, Scientific and Cultural Organization (UNESCO) Biosphere Reserve

Phytochemical analysis and antifungal activity of extracts from leaves and fruit residues of brazilian savanna plants aiming its use as safe fungicides

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)The increasing demand for safe food without preservatives or pesticides residues has encouraged several studies on natural products with antifungal activity and low toxicity. In this study, ethanolic extracts from leaves and fruit residues (peel and seeds) of three Brazilian savanna species (Acrocomia aculeata, Campomanesia adamantium and Caryocar brasiliense) were evaluated against phytopathogenic fungi. Additionally, the most active extract was chemically characterized by ESI-MS and its oral acute toxicity was evaluated. Extracts from C. brasiliense (pequi) peel and leaves were active against Alternaria alternata, Alternaria solani and Venturia pirina with minimal inhibitory concentrations between 350 and 1000 mu g/mL. When incorporated in solid media, these extracts extended the lag phase of A. alternata and A. solani and reduced the growth rate of A. solani. Pequi peel extract showed better antifungal activity and their ESI-MS analysis revealed the presence of substances widely reported as antifungal such as gallic acid, quinic acid, ellagic acid, glucogalin and corilagin. The oral acute toxicity was relatively low, being considered safe for use as a potential natural fungicide. [GRAPHICS] .The increasing demand for safe food without preservatives or pesticides residues has encouraged several studies on natural products with antifungal activity and low toxicity. In this study, ethanolic extracts from leaves and fruit residues (peel and seeds6195204FAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOFundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)2011/19057-7; 2012/21395-0We are grateful to São Paulo Research Foundation for the financial support of this research and for the fellowships awarded to C.A.B. (FAPESP No. 2011/19057-7) and G.A.B. (FAPESP No. 2012/21395-0) and to Study Group of Cerrado Agro-industrial Processes (

Gas chromatography coupled to high resolution time-of-flight mass spectrometry as a high-throughput tool for characterizing geochemical biomarkers in sediments

FAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOThe performance of gas chromatography coupled to high-resolution time-of-flight mass spectrometry (GC-HRTofMS) for characterizing geochemical biomarkers from sediment samples was evaluated. Two approaches to obtain the geochemical biomarkers were tested:2018FAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOFAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO2012/21395-0The authors would like to thank FAPESP (scholarship 2012/21395-0) for sponsoring this stud

Molecular characterization of sedimentary organic matter by chromatographic techniques and mass spectrometry

Orientador: Marcos Nogueira EberlinTese (doutorado) - Universidade Estadual de Campinas, Instituto de QuímicaResumo: Este trabalho emprega uma abordagem integrativa baseada em espectrometria de massas de ultra-alta resolução (UHR-MS), cromatografia líquida acoplada à espectrometria de massas sequencial (UHPLC¿MS/MS) e cromatografia gasosa bidimensional abrangente (GC×GC) na caracterização de matéria orgânica sedimentar. A técnica de GC×GC foi empregada na caracterização simultânea de diversas classes de biomarcadores geoquímicos eliminando a etapa de fracionamento e consumo de solvente, bem como diminuindo o tempo de análise. Os cromatogramas bidimensionais apresentaram perfis com regiões bem definidas para isoprenóides, alquilbenzenos, n-alcanos, n-álcoois, n-cetonas, n-ácidos graxos, esteróis, esteranos e diasteranos, hopanos, triterpenóides e compostos policíclicos aromáticos. Um método analítico por UHPLC¿MS/MS foi desenvolvido, validado e aplicado na determinação quantitativa de esteróis e triterpenóides. O método apresentou parâmetros analíticos adequados e corrida cromatográfica de 10 minutos, dispensando as etapas de separação prévia e de derivatização. Essa abordagem permitiu a avaliação das fontes de matéria orgânica e do aporte de esgoto doméstico nos diferentes ambientes de estudo. A análise direta por UHR-MS com ionização por eletrospray foi empregada na caracterização da parcela de compostos polares. Diversas classes de compostos foram identificadas representando um avanço no conhecimento a cerca da constituição da matéria orgânica sedimentar. O emprego da abordagem integrativa baseada em diferentes técnicas cromatográficas e de espectrometria de massas permitiu uma caracterização sem precedentes da composição química da matéria orgânica sedimentar, sendo as técnicas utilizadas complementaresAbstract: This study employs an integrative approach based on ultrahigh resolution mass spectrometry (UHR-MS), ultrahigh performance liquid chromatography coupled to tandem mass spectrometry (UHPLC¿MS/MS) and comprehensive two-dimensional gas chromatography (GC×GC) for the characterization of sedimentary organic matter. The GC×GC technique was employed for a simultaneous characterization of diverse geochemical biomarkers classes and indicators of petroleum-derived organic matter, eliminating fractionation steps, solvent consumption, and also reducing the analysis time. Bidimensional chromatograms displayed chemical profiles with well-defined regions for isoprenoids, alkylbenzenes, n-alkanes, n-alkanols, n-ketones, n-alkanoic acids, sterols, sterenes, diasterenes, hopanes, triterpenoids, and polycyclic aromatic hydrocarbons. An analytical method based on UHPLC¿MS/MS was developed, validated, and then applied in the determination of sterols and triterpenoids. This method showed acceptable analytical parameters and chromatographic run of ten minutes, eliminating both previous separation and derivatization steps. This approach allowed the evaluation of the organic matter sources and input of domestic sewage in different environments. Direct analysis by UHR-MS with electrospray ionization was employed for the characterization of the polar composition (non-GC amenable material). Diverse classes were identified, representing an expansion of the knowledge regarding sedimentary organic matter composition. The use of the proposed integrative approach based on different chromatographic techniques and mass spectrometry allowed an unprecedented inventory of the chemical composition of sedimentary organic matter, for which the used techniques were complementaryDoutoradoQuimica AnaliticaDoutora em Ciências2012/21395-0FAPES

Fatty Acid Biomarkers In Sediment Samples Via Ultra-high Resolution And Accuracy Time-of-flight Mass Spectrometry

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)This study proposes a new and fast protocol using ultra-high resolution (Rp of 100,000) and accuracy (<= 1 ppm) mass spectrometry in a "zig-zag" time-of-flight analyzer with electrospray ionization in the negative ion mode (ESI(-)-UHR TOF-MS) for direct screening of free fatty acids (FA) in sediments. As a proof-of-concept study, the profiles of FA in surface sediments from contrasting environments, including estuarine, coastal, and polar samples, and a sedimentary core were assessed. The profiles of saturated FA from C-12-C-36 revealed a strong even-over-odd preference with specific distributions for each selected environment. The terrigenous/aquatic ratio (TAR) and average chain length (ACL) proxies were calculated based on results obtained by ESI(-)-UHR TOF-MS and GC-MS for all the samples to validate the proposed protocol. Applying the paired t-test at a confidence level of 95%, we found a t-statistic equal to 2.05 for TAR and 2.01 for ACL, which are lower than the critical value of t. Thus, there is no significant difference between the results obtained by the two techniques at a confidence level of 95%. In addition, ESI(-)-UHR TOF-MS exhibited lower limits of quantification for free FA (10 ng/ml) compared to those obtained by GC-MS for fatty acid methyl esters (FAME) (50 ng/ml). Direct ESI(-)-UHR TOF-MS offers therefore a reliable, fast, and relatively simple MS protocol to obtain free FA profiles from sediments. The results strongly suggest that the method presented herein has future geochemical applications in the rapid screening of FA biomarkers in sediment samples, reducing both sample preparation as well as analysis time. (C) 2015 Elsevier Ltd. All rights reserved.922431Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)FAPESP [2012/21395-0]FAPESP [2006/04344-2