Spelling suggestions: "subject:"sas chromatography - mass spectrometry"" "subject:"sas chromatography - dass spectrometry""
81 |
A multi-instrument investigation of pigments, binders and varnishes from Egyptian paintings (AD 1300-1900) : molecular and elemental analysis using Raman, GC-MS and SEM-EDX techniquesAbdel-Ghani, Mona Hussien January 2009 (has links)
The focus of this study was analytical investigations of Egyptian paintings, mainly Coptic icons and Islamic wooden ceilings, dating from 1300-1900 using multi-instrumental techniques. Twenty three Coptic icons and three wooden ceilings dated from different periods and painted by different painters in case of icons were examined. The materials used including pigments, media, varnishes, ground layers and gold layers. The surface stratigraphy of paint samples, their layered structured and the composition of materials used in each layer were analysed. Variations in painting techniques, pigments palettes, paint media and varnishes applied in Egyptian paintings according to painters, time and type of paintings were revealed. A total of twenty-eight organic and inorganic pigments were identified in this study, of which nine have never been previously included as a part of the Egyptian pigment palettes, namely; smalt, lapis lazuli, indigo, pararealgar, Prussian blue, chrome yellow, barium yellow, barium white and hydromagnesite. The identification of hydromagnesite, which has never been to date considered as a pigment either in Egypt or elsewhere and the identification of smalt from the mid-14th century, whose reported earliest large scale use was in the 16th century. Two types of resins were identified as a constituent of the oil/resin varnish applied on Coptic icons of which Venice turpentine has been identified for the first time as an ingredient of Egyptian varnishes. The identification of mosaic gold in an 18th C. icon, a novel usage of dammar resin and the multilayered structure of the white ground layers were revealed.
|
82 |
Olive oil or lard?: distinguishing plant oils from animal fats in the archeological record of the eastern Mediterranean using gas chromatography/combustion/isotope ratio mass spectrometrySteele, V. J., Stern, B., Stott, A. W. January 2010 (has links)
Distinguishing animal fats from plant oils in archaeological residues is not straightforward. Characteristic plant sterols, such as beta-sitosterol, are often missing in archaeological samples and specific biomarkers do not exist for most plant fats. Identification is usually based on a range of characteristics such as fatty acid ratios, all of which indicate that a plant oil may be present, none of which uniquely distinguish plant oils from other fats. Degradation and dissolution during burial alter fatty acid ratios and remove short-chain fatty acids, resulting in degraded plant oils with similar fatty acid profiles to other degraded fats. Compound-specific stable isotope analysis of delta(13)C(18:0) and delta(13)C(16:0), carried out by gas chromatography/combustion/isotope ratio mass spectrometry (GC/C/IRMS), has provided a means of distinguishing fish oils, dairy fats, ruminant and non-ruminant adipose fats, but plant oils are rarely included in these analyses. For modern plant oils where C(18:1) is abundant, delta(13)C(18:1) and delta(13)C(16:0) are usually measured. These results cannot be compared with archaeological data or data from other modern reference fats where delta(13)C(18:0) and delta(13)C(16:0) are measured, as C(18:0) and C(18:1) are formed by different processes resulting in different isotopic values. Eight samples of six modern plant oils were saponified, releasing sufficient C(18:0) to measure the isotopic values, which were plotted against delta(13)C(16:0). The isotopic values for these oils, with one exception, formed a tight cluster between ruminant and non-ruminant animal fats. This result complicates the interpretation of mixed fatty residues in geographical areas where both animal fats and plant oils were in use.
|
83 |
Vznik nukleových bází z formamidu iniciovaný procesy o vysoké hustotě energie / Formation of nucleobases from formamide initiated by high-power density energy eventsMichalčíková, Regina January 2012 (has links)
This Master's thesis deals with determination of nucleobases in formamide samples (pure or catalyzed form) after their initiation by high-power density energy events. The theoretical part states the reader to the problems of prebiotic chemistry and acquaints him with the various theories of the origin of the nucleobases. The experimental part deals with the analysis of the samples initiated by Laser System PALS, which was used for the simulation high-power density energy events. For the identification and determination of the final products of laser plasma initiated chemical reactions in the gaseous phase of the samples was used the Fourier Transform Infrared Spectroscopy. The liquid part of the samples and the nucleobases in this part were analyzed by the gas chromatography with the mass detection.
|
84 |
Determinação de canabinóides em cabelo por microextração em fase sólida por Headspace e análise por espectrometria de massa associada à cromatografia em fase gasosa / Determination of cannabinoids in hair by Headspace solid-phase microextraction and gas chromatography-mass spectrometryOliveira, Carolina Dizioli Rodrigues de 21 July 2005 (has links)
Foi desenvolvido um método para determinar canabinóides (canabidiol, canabinol e delta-9-tetraidrocanabinol) no cabelo. Uma amostra de 10mg foi descontaminada com diclorometano, seguida de digestão alcalina, microextração em fase sólida por headspace (HS-SPME) e analisada por espectrometria de massa associada à cromatografia em fase gasosa (GC/MS). Os limites de detecção e de quantificação foram de 0,07 e 0,12 ng/mg, respectivamente, para todos canabinóides estudados. O método demonstrou ser simples, rápido, preciso e linear no intervalo de 0,12 a 12 ng/mg (r2 > 0,98). Amostras de cabelo de 8 usuários de Cannabis foram coletadas de pacientes provenientes de uma clínica dependentes pela equipe médica. O método mostrou-se eficiente em amostras de cabelos de usuários que faziam uso da droga pelo menos 10 vezes por semana. / A method was to develop to detect cannabinoids (cannabidiol, cannabinol and delta-9-tetrahydrocannabinol) in hair. A 10 mg of hair sample was descontaminated by dichloromethane followed by alkalin digestion, headspace solid-phase microextraction technique (HS-SPME) and analyzed by gas chromatography-mass spectrometry (CG/MS). The detection and quantitation limits were 0,07 and 0,12ng/mg respectively for all studied cannabinoids. The method proved to be simple, fast, precise and linear at the range of 0,12 to 12ng/mg (r2 > 0,98). Eight hair samples of Cannabis user were collected from patients at admittance from a dependence clinic by clinical staff. The method showed efficient in samples of users who use the drug at least 10 fold a week.
|
85 |
Desenvolvimento de polímeros de impressão molecular para microextração em ponteiras de bisfenol A em amostras de urina e análise por GC-MS / Development of molecularly imprinted polymer for disposable pipette extraction of bisphenol A in biological samples and analysis by GC-MSBrigante, Tamires Amabile Valim 26 October 2015 (has links)
O Bisfenol A (BPA, acrônimo da língua inglesa - bisphenol A) é uma substância utilizada na fabricação de embalagens alimentícias e resinas odontológicas. Sua toxicidade deve-se ao fato de que, como disruptor endócrino, afeta o sistema reprodutor, cardiovascular, neuro-endócrino e pode apresentar potencial carcinogênico. Em métodos bioanalíticos, o preparo da amostra tem sido requerido para aumentar a seletividade e sensibilidade analítica, através da remoção dos interferentes da amostra biológica e concentração dos analitos, quase sempre presentes em níveis de traços. A microextração em ponteiras (DPX, acrônimo das iniciais em língua inglesa - Disposable Pipette Extraction), baseada no equilíbrio de sorção do soluto com a fase extratora, consiste em uma ponteira padrão de micropipeta modificada, na qual o sorvente está contido livremente entre dois filtros, permitindo rápida extração do analito em diferentes matrizes complexas. Os polímeros de impressão molecular (MIP acrônimo das iniciais em língua inglesa - Molecularly Imprinted Polymer) consistem em uma rede polimérica tridimensional que possui cavidades seletivas para o reconhecimento molecular do analito ou de substâncias de estrutura análoga. Essa rede polimérica é sintetizada ao redor da substância molde (analito), e a cavidade seletiva é formada após a remoção do molde. As vantagens do processo sol-gel para a síntese do MIP são o controle do tamanho e forma das partículas, ajuste da hidrofobicidade e alta estabilidade térmica. No presente trabalho, o MIP foi sintetizado e utilizado como sorvente para a técnica DPX para a determinação de bisfenol A em amostras de urina por cromatografia em fase gasosa acoplada à espectrometria de massas (GC-MS, acrônimo das iniciais em língua inglesa - Gas Chromatography coupled to Mass Spectrometry). O MIP foi sintetizado pela via sol-gel utilizando aminopropiltrietoxisilano (APTES) como mônomero funcional e tetraetil-orto-silicato (TEOS) como reagente de ligação cruzada. Como molde foram avaliados o BPA para o MIP, e o tetrabromobisfenol A (TBBPA) para o polímero molecularmente impresso com molécula análoga ao analito (DMIP, acrônimo das iniciais em língua inglesa - Dummy Molecularly Imprinted Polymer). Para avaliar a seletividade do MIP, o polímero não impresso (NIP, acrônimo das iniciais em língua inglesa - Non-imprinted Polymer) foi sintetizado seguindo o mesmo procedimento de síntese do MIP com exceção da adição da molécula molde. Apesar de a capacidade de sorção do MIP ser ligeiramente maior, o DMIP foi selecionado como sorvente para minimizar o efeito de memória. O DMIP foi caracterizado por microscopia eletrônica de varredura (MEV) e por espectroscopia vibracional na região do infravermelho por transformada de Fourier (FTIR, acrônico das inicias em língua inglesa - Fourier Transform Infrared). Os parâmetros da técnica DPX, tais como, o tempo de equilíbrio de sorção entre a amostra e o sorvente e condições de dessorção foram otimizadas por técnicas quimiométricas. A robustez do DMIP sintetizado via sol-gel foi comprovada pela reutilização deste sorvente por mais de 100 vezes, sem perda da eficiência da extração. O método desenvolvido DPX/GC-MS apresentou linearidade na faixa de 50 a 500 ng mL-1, precisão com CV (coeficientes de variação) entre 4 e 14% e de exatidão com valores de erro padrão relativo (EPR) de -13,6 a 12,3%. O método de referência utilizando a extração líquido-líquido e GC-MS (LLE/GC-MS), faixa de linearidade de 5 a 50 ng mL-1, foi desenvolvido e validado. Embora o método DPX/GC-MS inovador, quando comparado ao LLE/GC-MS, tenha apresentado maior limite de quantificação, apresentou as seguintes vantagens: simplicidade, rapidez e utilização de menores volumes de amostra e de solventes orgânicos na etapa do preparo da amostra / Bisphenol A (BPA) is widely used in food package and dental resins manufacturing. Its toxicity is due to its endocrine disruptor activity that affects the reproductive, cardiovascular, neurological system and may have carcinogenic potential. In bioanalytical methods the sample preparation has been required to increase the selectivity and analytical sensibility by removing the interfering from the biological matrix and concentration of the analytes that are in trace levels most of the times. The disposable pipette extraction (DPX) is based on sorption equilibrium of the analyte between the sample and the extraction phase. It consists in a pipette that contais the sorbent phase freely between two filters. Then, the extraction of the solute from the complex sample occurs quickly. Molecularly imprinted polymer is a tridimensional polimeric network that has selectivity cavities that can recognize an analyte or a substance with a similar structure. The polimeric network is synthesized around to a template molecule and after removing this template, a selective cavity is formed. The advantages of the sol-gel process for the synthesis of MIP are the control of the size and shape of the particles, hydrophobicity adjustment and high thermal stability. In the present study MIP was synthesized and used as sorbent to DPX method for determination of BPA in urine samples by gas chromatography coupled to mass spectrometry (GC-MS). Sol-gel methodoly was used to synthesize the polymers. Aminopropyltriethoxysilane (APTES) was used as a functional monomer and tetraethyl orthosilicate (TEOS) as crosslinking reagent. BPA and tetrabromobisphenol A (TBBPA) were evaluated as template to the synthesis of MIP and dummy molecularly imprinted polymer (DMIP) which is a molecularly imprinted polymer that uses a template structurally similar to the analyte. The non-imprinted polymer (NIP) was synthesized following the same procedure that MIP, except for the addition of template. It was made to verify the improvement of selectivity and sensibility of molecularly imprinted polymers. Although the sorption capacity of the MIP is slightly larger, DMIP has been selected as a sorbent in order to minimize the memory effect. The DMIP was characterized by Scanning Electron Microscopy (SEM) and Fourier Transform Infrared spectroscopy (FTIR). The parameters of DPX, such as time sorption equilibrium between the sample and the sorbent and desorption conditions were optimized by chemometrics. Robustness of DMIP sinthesized by sol-gel process was evidenciated for the reuse of DMIP for more than a 100 times. The developed method DPX/GC-MS showed linearity on the range from 50 to 500 ng ml-1, precision values with coefficient of variation (CV) betweeen 4 and 14% and accuracy with relative standard deviation values (RSD) from -13.6 to 12.3%. The reference method using liquid- liquid extraction and GC-MS (LLE/GC-MS) was developed and validated, showing linearity from 0.5 to 50 ng mL-1. Althout the innovative method DPX/GC-MS has showed limit of quantification larger than LLE/GC-MS, it presents the following advantages: simplicity, rapidy and utilization of smaller volumes of organic solvents on the sample preparation step
|
86 |
Estudo do metaboloma de biofluidos em pacientes pediátricos nefropatas e sua associação com a doença periodontal / Metabolomics study of biofluids of paediatric patients with chronic kidney disease and its association with periodontitisAlves, Levy Anderson César 01 September 2016 (has links)
Metabolômica é a técnica que analisa quantitativamente metabólitos endógenos e exógenos de baixa massa molecular encontrados em biofluidos e tecidos. Estas pequenas moléculas representativas encontradas em um sistema biológico abrangem carboidratos, ácidos graxos, nucleotídeos, aminoácidos entre outras classes de compostos. Alguns estudos têm mostrado a importância da manutenção da saúde bucal para pacientes com doença renal crônica (DRC). DRC, um problema mundial de saúde pública, pode ser definida em função da presença de danos renais ou de uma taxa de filtração glomerular < 60 mL/min por 1.73m2 por 3 meses, independente da causa. Desta forma, o objetivo deste estudo foi identificar e interpretar a função de metabólitos salivares e de urina de pacientes com DRC e sua possível associação com a doença periodontal (DP). Trinta adolescentes e adultos jovens, 12-18 anos, diagnóstico médico definitivo de DRC, cadastrados no CAPE (Centro de atendimento a pacientes especiais) da Faculdade de Odontologia e no Instituto da Criança da Faculdade de Medicina - Universidade de São Paulo (USP), fizeram parte deste estudo. O grupo controle também foi composto por 30 indivíduos, porém, clinicamente saudáveis. Todos os participantes receberam informações prévias à coleta de urina e saliva. As amostras de saliva e a primeira urina da manhã foram coletadas e armazenadas a -80°C até a realização da análise. A análise periodontal foi realizada por meio do índice de higiene oral simplificado (OHI-S), sangramento à sondagem e profundidade de sondagem. Todas as amostras foram avaliadas no departamento de Engenharia Química da Escola Politécnica da USP por meio de análise de cromatografia gasosa acoplada ao espectrômetro de massa (GC-MS). As análises estatísticas foram realizadas por meio da análise de componentes principais (PCA), testes de Mann-Whitney e Kruskal-Wallis. A quantificação relativa de cada metabólito mostrou maiores concentrações estatisticamente significativas entre pacientes com DRC sem DP e com DRC e com DP, de alanina (p<0.0001), glicina (p<0.0001), tirosina (p=0.021), serina (p<0.0001), prolina (p<0.0002), leucina (p<0.0003), citrulina (p<0.0001) e arginina (p<0.0002). Os valores médios da concentração de p-Cresol também mostraram-se alterados para os mesmos grupos citados acima. Grupos com DRC mostraram concentrações alteradas de ácidos carboxílicos como ácido butírico e de dimetilarginina. Concluímos, portanto, que ambas as patologias estimulam o processo oxidativo sintetizando metabólitos como ácido butírico, L-prolina, dentre outros, os quais podem potencializar a severidade da DRC. Verificamos também que, apesar do perfil metabólico ser diferente, alguns metabólitos como uréia, creatinina, ácido octadecanóico, ciclohexano, são compartilhados por todos os grupos. / Metabolomics is a quantitative analysis of biofluids and tissue for low molecular mass organic endogenous / exogenous metabolites. These representative small molecules found within a system cover a broad range of small molecules, such as carbohydrates, fatty acids, nucleotides, amino acids among many other classes of compounds. A few studies have been published focusing on the oral health of chronic kidney disease (CKD) patients. CKD, a public health problem worldwide, can be defined based on the presence of kidney damage or glomerular filtration rate (GFR) < 60 mL/min per 1.73m2 for 3 months, regardless of cause. On account of that, the aim of this study was to identify and interpret the role of saliva and urine metabolites of CKD individuals and their possible association with periodontitis (PD). Thirty adolescents and young adults, aged 12-18 years, with definite medical diagnosis of CKD and attending the CAPE (Center of Attendance for Special Needs Patients) of the Dental School and the Children Institute of the Medical School - University of São Paulo (USP), comprised the study. The control group was comprised of 30 clinically healthy individuals. Participants were asked to refrain from oral activities for 2 h prior to saliva collection. The first morning urine was also collected and both specimens were frozen at -80°C until assay. Periodontal evaluation was carried out by means of the simplified oral hygiene index (OHI-S), bleeding on probing and probing depth. All samples were analyzed in the Chemical Engineering Department of the Polytechnics School of USP, by means of the Gas-chromatography - mass spectrometry (GC-MS) technique. Statistical analyses were performed by means of the principal component analysis (PCA), Mann-Whitney and Kruskal-Wallis tests. The relative quantification showed higher levels of alanine (p<0.0001), glycine (p<0.0001), tyrosine (p=0.021), serine (p<0.0001), proline (p<0.0002) ,leucine (p<0.0003), citrulline (p<0.0001) and arginine (p<0.0002) for groups II and IV. The mean concentration of p-Cresol was also greater and statically significant when comparing groups II and IV. Groups with CKD displayed higher concentrations of carboxylic acids such as butyric acid, and also of dimetilarginine. In conclusion, it could be verified that both pathologies stimulate oxidative stress which synthetises metabolites such as butyric acid and L-proline which can potentialise the severity of CKD. Additionally, despite being possible to distinguish the metabolic profile of patients with PD, PD and CKD and only CKD from clinically healthy individuals, some of these metabolites such as acetic acid, urea, creatinine, octadecanoic acid and cyclohexane were shared among all groups.
|
87 |
Plasma F2-isoprostanes in healthy and diabetic subjects: analysis by mass spectrometry. / CUHK electronic theses & dissertations collectionJanuary 2000 (has links)
Zhao Zheng. / "December 2000." / On t.p. "2" is subscript. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2000. / Includes bibliographical references (p. 187-241). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Mode of access: World Wide Web. / Abstracts in English and Chinese.
|
88 |
Determinação de canabinóides em cabelo por microextração em fase sólida por Headspace e análise por espectrometria de massa associada à cromatografia em fase gasosa / Determination of cannabinoids in hair by Headspace solid-phase microextraction and gas chromatography-mass spectrometryCarolina Dizioli Rodrigues de Oliveira 21 July 2005 (has links)
Foi desenvolvido um método para determinar canabinóides (canabidiol, canabinol e delta-9-tetraidrocanabinol) no cabelo. Uma amostra de 10mg foi descontaminada com diclorometano, seguida de digestão alcalina, microextração em fase sólida por headspace (HS-SPME) e analisada por espectrometria de massa associada à cromatografia em fase gasosa (GC/MS). Os limites de detecção e de quantificação foram de 0,07 e 0,12 ng/mg, respectivamente, para todos canabinóides estudados. O método demonstrou ser simples, rápido, preciso e linear no intervalo de 0,12 a 12 ng/mg (r2 > 0,98). Amostras de cabelo de 8 usuários de Cannabis foram coletadas de pacientes provenientes de uma clínica dependentes pela equipe médica. O método mostrou-se eficiente em amostras de cabelos de usuários que faziam uso da droga pelo menos 10 vezes por semana. / A method was to develop to detect cannabinoids (cannabidiol, cannabinol and delta-9-tetrahydrocannabinol) in hair. A 10 mg of hair sample was descontaminated by dichloromethane followed by alkalin digestion, headspace solid-phase microextraction technique (HS-SPME) and analyzed by gas chromatography-mass spectrometry (CG/MS). The detection and quantitation limits were 0,07 and 0,12ng/mg respectively for all studied cannabinoids. The method proved to be simple, fast, precise and linear at the range of 0,12 to 12ng/mg (r2 > 0,98). Eight hair samples of Cannabis user were collected from patients at admittance from a dependence clinic by clinical staff. The method showed efficient in samples of users who use the drug at least 10 fold a week.
|
89 |
Estudo do metaboloma de biofluidos em pacientes pediátricos nefropatas e sua associação com a doença periodontal / Metabolomics study of biofluids of paediatric patients with chronic kidney disease and its association with periodontitisLevy Anderson César Alves 01 September 2016 (has links)
Metabolômica é a técnica que analisa quantitativamente metabólitos endógenos e exógenos de baixa massa molecular encontrados em biofluidos e tecidos. Estas pequenas moléculas representativas encontradas em um sistema biológico abrangem carboidratos, ácidos graxos, nucleotídeos, aminoácidos entre outras classes de compostos. Alguns estudos têm mostrado a importância da manutenção da saúde bucal para pacientes com doença renal crônica (DRC). DRC, um problema mundial de saúde pública, pode ser definida em função da presença de danos renais ou de uma taxa de filtração glomerular < 60 mL/min por 1.73m2 por 3 meses, independente da causa. Desta forma, o objetivo deste estudo foi identificar e interpretar a função de metabólitos salivares e de urina de pacientes com DRC e sua possível associação com a doença periodontal (DP). Trinta adolescentes e adultos jovens, 12-18 anos, diagnóstico médico definitivo de DRC, cadastrados no CAPE (Centro de atendimento a pacientes especiais) da Faculdade de Odontologia e no Instituto da Criança da Faculdade de Medicina - Universidade de São Paulo (USP), fizeram parte deste estudo. O grupo controle também foi composto por 30 indivíduos, porém, clinicamente saudáveis. Todos os participantes receberam informações prévias à coleta de urina e saliva. As amostras de saliva e a primeira urina da manhã foram coletadas e armazenadas a -80°C até a realização da análise. A análise periodontal foi realizada por meio do índice de higiene oral simplificado (OHI-S), sangramento à sondagem e profundidade de sondagem. Todas as amostras foram avaliadas no departamento de Engenharia Química da Escola Politécnica da USP por meio de análise de cromatografia gasosa acoplada ao espectrômetro de massa (GC-MS). As análises estatísticas foram realizadas por meio da análise de componentes principais (PCA), testes de Mann-Whitney e Kruskal-Wallis. A quantificação relativa de cada metabólito mostrou maiores concentrações estatisticamente significativas entre pacientes com DRC sem DP e com DRC e com DP, de alanina (p<0.0001), glicina (p<0.0001), tirosina (p=0.021), serina (p<0.0001), prolina (p<0.0002), leucina (p<0.0003), citrulina (p<0.0001) e arginina (p<0.0002). Os valores médios da concentração de p-Cresol também mostraram-se alterados para os mesmos grupos citados acima. Grupos com DRC mostraram concentrações alteradas de ácidos carboxílicos como ácido butírico e de dimetilarginina. Concluímos, portanto, que ambas as patologias estimulam o processo oxidativo sintetizando metabólitos como ácido butírico, L-prolina, dentre outros, os quais podem potencializar a severidade da DRC. Verificamos também que, apesar do perfil metabólico ser diferente, alguns metabólitos como uréia, creatinina, ácido octadecanóico, ciclohexano, são compartilhados por todos os grupos. / Metabolomics is a quantitative analysis of biofluids and tissue for low molecular mass organic endogenous / exogenous metabolites. These representative small molecules found within a system cover a broad range of small molecules, such as carbohydrates, fatty acids, nucleotides, amino acids among many other classes of compounds. A few studies have been published focusing on the oral health of chronic kidney disease (CKD) patients. CKD, a public health problem worldwide, can be defined based on the presence of kidney damage or glomerular filtration rate (GFR) < 60 mL/min per 1.73m2 for 3 months, regardless of cause. On account of that, the aim of this study was to identify and interpret the role of saliva and urine metabolites of CKD individuals and their possible association with periodontitis (PD). Thirty adolescents and young adults, aged 12-18 years, with definite medical diagnosis of CKD and attending the CAPE (Center of Attendance for Special Needs Patients) of the Dental School and the Children Institute of the Medical School - University of São Paulo (USP), comprised the study. The control group was comprised of 30 clinically healthy individuals. Participants were asked to refrain from oral activities for 2 h prior to saliva collection. The first morning urine was also collected and both specimens were frozen at -80°C until assay. Periodontal evaluation was carried out by means of the simplified oral hygiene index (OHI-S), bleeding on probing and probing depth. All samples were analyzed in the Chemical Engineering Department of the Polytechnics School of USP, by means of the Gas-chromatography - mass spectrometry (GC-MS) technique. Statistical analyses were performed by means of the principal component analysis (PCA), Mann-Whitney and Kruskal-Wallis tests. The relative quantification showed higher levels of alanine (p<0.0001), glycine (p<0.0001), tyrosine (p=0.021), serine (p<0.0001), proline (p<0.0002) ,leucine (p<0.0003), citrulline (p<0.0001) and arginine (p<0.0002) for groups II and IV. The mean concentration of p-Cresol was also greater and statically significant when comparing groups II and IV. Groups with CKD displayed higher concentrations of carboxylic acids such as butyric acid, and also of dimetilarginine. In conclusion, it could be verified that both pathologies stimulate oxidative stress which synthetises metabolites such as butyric acid and L-proline which can potentialise the severity of CKD. Additionally, despite being possible to distinguish the metabolic profile of patients with PD, PD and CKD and only CKD from clinically healthy individuals, some of these metabolites such as acetic acid, urea, creatinine, octadecanoic acid and cyclohexane were shared among all groups.
|
90 |
Evaluation Of Persistent Organic Pollutants (pops) In Balikesir Dam Lake SedimentsGokmen, Pinar 01 February 2011 (has links) (PDF)
In this study, the Persistent Organic Pollutants (POPs) specifically / 17
Organochlorine Pesticides (OCPs) and 19 Polycyclic Aromatic Hydrocarbons
(PAHs) were evaluated in the sediment samples of Balikesir (Ikizcetepeler) Dam
Lake. Sixteen sampling points were chosen for determination of concentrations of
OCPs and PAHs After ultrasonic bath extraction of the sediment samples GC-MS
was used as analytical tool. Extraction efficiencies changes from 63.8 to 87.4%
depending on the type of the POPs. Average OCP concentration was found in the
range of 3.33-379 µ / g/kg a, average PAH concentration was found in the range of
3.28-32.9 µ / g/kg. Pollution maps regarding OCP and PAH distributions were drawn
and the correlation between these two pollutant types was investigated. The quality
control (QC) and quality assurance tests were applied by the analysis of standard
reference materials (SRMs), surrogate standards and analysis replicates.
|
Page generated in 0.182 seconds