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An enantioselective heart-cut two-dimensional liquid chromatography-atmospheric pressure photoionization-tandem mass spectrometry method was developed for the analysis of 25 methylsulfonyl polychlorinated biphenyl metabolites in tissue extracts. Enantioseparation was achieved for 9 out of the 10 chiral analytes in less than 91 minutes, improving upon previous gas chromatography-based methods. Use of a pyrenyl-ethyl silica column in the first dimension enabled separation of all but two pairs of isobaric analytes. Limits of detection of 0.01 to 1.73 ng on-column were achieved. The precision and accuracy were within acceptable limits, but poor sensitivity was achieved for several meta-methylsulfonyl-substituted congeners. Despite this limitation, the method was successfully applied to the analysis of Greenland sledge dog (Canis familiaris) plasma and adipose tissue extracts. Concentration and enantiomer fraction data are presented. None of the target analytes were detected in Norwegian glaucous gull (Larus hyperboreus) plasma extracts.

Sample preparation is often a bottleneck in systems for chemical analysis. The aim of this work was to investigate and develop new techniques to address some of the shortcomings of current sample preparation methods. The goal has been to provide full automation, on-line coupling to detection systems, short sample preparation times and high-throughput. In this work a new technique for sample preparation that can be connected on-line to liquid chromatography (LC) and gas chromatography (GC) has been developed. Microextraction in packed syringe (MEPS) is a new solid-phase extraction (SPE) technique that is miniaturized and can be fully automated. In MEPS approximately 1 mg of sorbent material is inserted into a gas tight syringe (100-250 μL) as a plug. Sample preparation takes place on the packed bed. Evaluation of the technique was done by the determination of local anaesthetics in human plasma samples using MEPS on-line with LC and tandem mass spectrometry (MS-MS). MEPS connected to an autosampler was fully automated and clean-up of the samples took about one minute. In addition, in the case of plasma samples the same plug of sorbent could be used for about 100 extractions before it was discarded. A further aim of this work was to increase sample preparation throughput. To do that disposable pipette tips were packed with a plug of porous polymer monoliths as sample adsorbent and were then used in connection with 96-well plates and LC-MS-MS. The evaluation of the methods was done by the analysis of local anaesthetics lidocaine and ropivacaine, and anti-cancer drug roscovitine in plasma samples. When roscovitine and lidocaine in human plasma and water samples were used as model substances, a 96-plate was handled in about two minutes. Further, disposable pipette tips may be produced at low cost and because they are used only once, carry-over is eliminated.

Thesis (Ph. D.)--University of Washington, 2006. / Vita. Includes bibliographical references (leaves 137-143).

Metabólitos secundários produzidos por actinobactérias são uma inesgotável fonte de compostos com potentes atividades biológicas e estruturas intrínsecas. O desenvolvimento em instrumentação analítica tem contribuído significantemente para acelerar o processo de identificação e caracterização desses metabólitos bioativos. Sem dúvida alguma, a espectrometria de massas (MS) e o seu acoplamento com técnicas de separação, especialmente a cromatografia líquida (UHPLC-MS), tem sido reconhecida como a técnica mais eficiente em análises de produtos naturais. Nesta dissertação foi explorado o potencial da espectrometria de massas como ferramenta analítica para a identificação e caracterização estrutural de fitotoxinas produzidas por actinobactérias isoladas da rizosfera de plantas da caatinga. Foram produzidos noventa extratos de actinobactérias, dos quais quinze apresentaram alguma atividade para o bioensaio da Lemna minor e seis apresentaram atividade para o bioensaio da Chlorella vulgaris. Os extratos brutos ativos das actinobactérias Caat 7-38, Caat 8-6 e Caat 5-29 foram selecionados para caracterização dos compostos ativos, os quais foram isolados empregando o fracionamento guiado por bioensaios. No extrato bruto Caat 7-38, a actinomicina D foi identificada como fitotoxina, ao passo que para o extrato bruto Caat 8-6, foi possível inferir a atividade fitotóxica à presença do griseorhodin A. Já para o extrato bruto Caat 5-29, o composto identificado com atividade fitotóxica apresenta uma estrutura inédita, provavelmente pertencente à classe das anguciclinonas. Foi realizado ainda um estudo para avaliar o efeito da adição de terras raras ao meio de cultivo da actinobacteria Caat 7-38. Para os meios de cultivos contendo neodímio e, principalmente, lantânio ocorreu uma superprodução da actinomicina D, indicando assim, o grande potencial da aplicação das terras raras nos estudos de micro-organismos. / Secondary metabolites produced by actinomycetes are an inexhaustible source of compounds with potent biological activities and intrinsic structures. The development analytical instrumentation has contributed significantly to accelerate the identification and characterization of these bioactive metabolites. Undoubtedly, mass spectrometry (MS) and its coupling with separation techniques, especially liquid chromatography (UHPLC-MS) has been recognized as the most \"efficient\" technique in natural product analysis. In this work was explored the potential of mass spectrometry as an analytical tool for identification and structural characterization of phytotoxins produced by actinomycetes isolated from the rhizosphere of plants from the Caatinga biome. Ninety actinomycetes extracts were produced, of which fifteen showed some activity for the bioassay with Lemna minor and six showed activity for the bioassay with Chlorella vulgaris. The crude active extract of actinomycetes Caat 7-38, Caat 8-6 and Caat 5-29 were selected to characterize the active compounds, which were isolated using bioassay-guided fractionation. In the crude extract Caat 7-38, actinomycin D was identified as phytotoxin, while for crude extract Caat 8-6, it was possible to infer phytotoxic activity to the presence of griseorhodin A. For the crude extract Caat 5-29, the compound identified with phytotoxic activity presents a new structure, probably belonging to the class of anguciclinones. A study to evaluate the effect of addition of rare earths to the culture medium of actinobacteria Caat 7-38 was also carried out. To the culture medium containing neodymium and especially lanthanum occurred overproduction of actinomycin D, thus indicating the great potential of application of rare earths in the studies of microorganisms.

Orientador: Isabel Cristina Sales Fontes Jardim / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Química / Made available in DSpace on 2018-08-25T19:47:02Z (GMT). No. of bitstreams: 1 Konatu_FernandaRibeiroBegnini_D.pdf: 4700112 bytes, checksum: d441f0c4d77f576a25490f2cd3c86e39 (MD5) Previous issue date: 2014 / Resumo: Segundo a Agência Nacional de Vigilância Sanitária (ANVISA), nos últimos anos, a alface tem apresentado irregularidades no Brasil, em relação à presença de agrotóxicos permitidos em limites acima do recomendável e/ou substâncias não autorizadas para o produto, tornando-se necessário o desenvolvimento de métodos para a determinação multirresíduos de agrotóxicos nesta cultura. A separação, confirmação e quantificação de 16 agrotóxicos em alface foi realizada por cromatografia líquida de alta eficiência e de ultra eficiência acopladas à espectrometria de massas sequencial, com analisador triplo quadrupolo, operando no modo de monitoramento de reações múltiplas e ionização positiva por eletrospray. Para a extração dos agrotóxicos, foi utilizado o método QuEChERS otimizado, empregando-se acetonitrila como solvente extrator, tampão citrato na etapa de particionamento, agitação por vórtex, centrifugação por 5 minutos a 5000 rpm e uso de uma mistura de PSA, MgSO4 e carbono grafitizado para realização da limpeza da amostra. Os métodos desenvolvidos foram validados, de acordo com o Documento SANCO No 12571/2013, mostrando-se seletivos, exatos e precisos, com recuperações na faixa de 70-120% e coeficientes de variação inferiores a 20%. A linearidade foi avaliada em 5 níveis de fortificação, empregando curvas analíticas por padronização externa com superposição de matriz, obtendo-se coeficientes de determinação acima de 0,990, resíduos menores que 20% e limites de quantificação acima de 3 µg/kg. Os métodos foram aplicados para diferentes variedades de alface (crespa, lisa, americana, mimosa e roxa) e para o espinafre (hortaliça de composição similar), obtendo-se bons resultados. Amostras adquiridas no comércio da região de Campinas-SP foram analisadas e agrotóxicos foram detectados em 43% das amostras, em limites não autorizados pela ANVISA, comprovando a necessidade do monitoramento contínuo da cultura de alface no Brasil / Abstract: According to the Brazilian Health Surveillance Agency, in recent years, lettuce has shown irregularities in Brazil, due to the presence of pesticides at levels above the permissible maximum residue level. Therefore, the development of a multi-residue method for determination of pesticides in lettuce becomes necessary. For this, the separation, confirmation and quantification of 16 pesticides in lettuce was realized using high- and ultra-high-performance liquid chromatography coupled to tandem mass spectrometry with a triple quadrupole mass analyzer, operating in a multiple reaction monitoring mode with positive electrospray ionization. The pesticide extraction was performed using an optimized QuEChERS method, employing acetonitrile as extraction solvent, citrate buffer as partitioning salt, vortex agitation, centrifugation at 5000 rpm for 5 minutes and clean-up with PSA, MgSO4 and graphitized carbon black. The methods developed were validated according to Document SANCO No 12571/2013, and proved to be selective, accurate and precise, presenting recoveries from 70 to 120% and a relative standard deviation = 20% for all pesticides. Linearity was evaluated at 5 levels of fortification, employing matrix-matched standard solutions, providing coefficients of determination higher than 0.990, residuals = 20% and limits of quantification from 3 µg/kg. The methods were applied to several varieties of lettuce (green-leaf, looseleaf, iceberg, green-bowl and red-leaf) and to spinach (vegetable of similar composition), showing good results. Samples of several varieties of lettuce were purchased from commercial markets in Campinas, SP, and pesticides were detected in 43% of the samples at concentrations above the levels authorized by ANVISA, indicating the need to continue to monitor lettuce / Doutorado / Quimica Analitica / Doutora em Ciências

Endocrine disrupting chemicals (EDCs) are emerging contaminants that can interfere with the hormone system and may cause cancers, birth defects and reproductive system disorders. Prevalence of endocrine-related dysfunction and disease has increased steadily over the past decades. Although accumulating data suggest that these diseases have fetal origins, associations of EDC exposure during pregnancy and adverse health effects on both mothers and fetuses have not been thoroughly evaluated, particularly at multiple points in time. We firstly developed an analytical method for quantification of 28 EDCs (9 phthalates, 8 bisphenols, 5 parabens, 5 benzophenones and triclosan) in urine samples using ultra high performance liquid chromatography coupled with triple quadrupole mass spectrometer. The method was applied to measure targeted compounds in a total of 5220 urine samples collected from 951 pregnant women at three trimesters and 1501 pregnant women at one or two trimesters in Wuhan, China between 2014 and 2015. Based on the quantification results, exposure patterns and health risks of 28 EDCs on participants were evaluated and discussed in detail below. Among these samples, bisphenol A (BPA), bisphenol S (BPS), bisphenol F (BPF), methylparaben (MeP), ethylparaben (EtP), propylparaben (PrP), 4-hydroxybenzophenone (4-OH-BP), 2,4-dihydroxybenzophenone (BP-1), 2-hydroxy-4-methoxybenzophenone (BP-3), triclosan, mono(2-ethylhexyl) phthalate (MEHP), mono(2-ethyl-5-carboxypentyl) phthalate (MECPP), mono(2-ethyl-5-oxohexyl) phthalate (MEOHP), mono(2-ethylhexyl) phthalate (MEHHP), monobenzyl phthalate (MBzP), mono-n-butyl phthalate (MnBP), monoisobutyl phthalate (MiBP) were determined with detection rates exceeding 50%, in which BPA, BP-3, MeP and MnBP were the predominant compounds. We found the U-shaped trends of urinary concentrations of phthalate metabolites over trimesters. Parabens, benzophenones and triclosan displayed a downward trend over three visits. We also found the levels of targeted compounds varied by exposure-related factors, such as sampling seasons, physical activities, computer using time and decoration information. In addition, multiple EDCs were mostly determined at low doses over trimesters, indicating that real-world exposure of pollutants were dominated by low-dose mixtures. We then evaluated the combined health hazards induced by EDC exposure via calculating the estimated daily intakes on the basis of average urinary concentrations at three trimesters. It was found that 24.9% of participants had potential health risks caused by exposure to phthalate mixtures. The most frequency of cumulative risks occurred in women who were exposed to a high dose of one specific phthalate, di-n-butyl phthalate (DnBP) or di(2-ethylhexyl) phthalate (DEHP). We also evaluated the cumulative health risks of BPA and its alternatives and found that about 1.6% of participants were at risks induced by bisphenol exposure. Combined health hazards were mainly driven by one specific bisphenol (BPS or BPA). Our findings suggested that regional interventions of DnBP, DEHP, BPA and BPS in application and production should be tighten and/or taken. Considering the low-dose effects of BPA, we further investigated the associations of BPA and three major natural estrogens, including estrone (E1), estradiol (E2) and estriol (E3), at three trimesters of pregnancy. We observed non-monotonic dose-response relationships of BPA to E1, E2 and E3 over trimesters even when BPA concentrations were below the current safety thresholds. In the gender-stratified models, we found significant negative relationships (β < 0, p < 0.05) between BPA and E2 among mothers with male fetuses in the first trimester. However, we found that no significant relationship between BPA and E2 among mothers with female fetuses over three trimesters. Significant non-monotonic associations (from significant negative to positive associations) between BPA and E3 were observed among mothers with female fetuses in the second trimester. The above mentioned findings suggested the gender-specific and trimester-specific effects of BPA on estrogens. Our findings also indicated that the current tolerance daily intake value maybe not safe enough to evaluate the potential health risks induced by BPA exposure. We next investigated the effects of maternal exposure to phthalates on both mothers and fetuses. Associations of phthalate exposure with the risks of gestational diabetes mellitus (GDM) and plasma glucose levels were evaluated based on a nested case-control study design. It was found that the levels of phthalate metabolites in women with GDM were significantly higher than those without GDM. Meanwhile, positive associations between urinary concentrations of phthalate metabolites and the risks of GDM were obvious, indicating that phthalate exposure may be a risk factor for GDM. In addition, phthalate levels were related to the increased plasma glucose levels after 75 g oral glucose tolerance test. Our findings suggested that phthalates might disturb the glucose homeostasis and increase GDM risks. Furthermore, we assessed the trimester-specific and gender-specific effects of DEHP exposure on fetal growth, birth size and postnatal growth at 6, 12 and 24 months. We found that among male offspring, 1st-trimester DEHP was negatively related to fetal growth (β < 0, p < 0.05), but positively related to 24-month body mass index (BMI). 2nd-trimester DEHP was negatively related to fetal growth, birth weight and birth length, but positively related to the weight gain rates from birth to 12 months old. 3rd-trimester DEHP was positively (β > 0, p < 0.05) associated with birth weight, BMI at 6 and 12 months. However, among females, 1st-trimester DEHP was associated with increased birth length, while 2nd-trimester DEHP was negatively associated with BMI at 6 and 12 months. A negative association between DEHP and weight gain rates at 6 months was noted among females. Our findings indicated the second trimester maybe the sensitive window of DEHP exposure for offspring growth since 2nd-trimester DEHP levels were related to the decreased fetal growth, decreased birth size, but increased weight gain rates in early childhood age among male offspring. To investigate the mechanism underlying the associations of DEHP exposure with glucose and lipid metabolism, we investigated the biotransformation of DEHP and the disturbed metabolisms induced by MEHP, the putative toxic metabolite of DEHP, in human normal liver cell L02 using metabolomics and lipidomics. We found that MEHP was the major metabolite of DEHP. Decreased uptake of glucose and accumulation of glucose in liver cells were obvious after MEHP exposure. Phospholipid remodeling, incomplete fatty acid β-oxidation, inhibition of purine metabolism and glycolysis, and increased oxidative stress were noted in MEHP-exposed L02 cells, which were related to insulin resistance. In this work, we measured 28 EDCs in a total of 5220 urine samples provided by 951 pregnant women (three trimesters) and 1501 pregnant women (one or two trimesters) and then evaluated the exposure levels, exposure patterns (variations, variability and correlations), health risks and health effects of these compounds on pregnant women and fetuses. Our data suggested that participants had potential health risks induced by exposure to phthalates or bisphenols. Phthalate exposure was related with the increased plasma glucose levels and risks of GDM. Prenatal DEHP exposure may induce the intrauterine growth restriction and catch-up growth among males, which supported the evidence of fetal origin. To explore the underlying mechanisms of MEHP on glucose and lipid metabolic disorders, we exposed the human normal hepatic L02 cells with MEHP, and applied metabolomic and lipidomic approaches for finding potential biomarkers and disturbed pathways. We found that MEHP exposure inhibited glucose uptake, caused phospholipid remodeling and increased oxidative stress in L02. These findings suggest that the usage of products containing EDCs, particularly phthalates, in pregnant women should be limited in China, intervention of BPS should be considered, and threshold values of BPA are called for reevaluation.

<p>Advancements in 3D printing technology have provided (1) easy access to low-cost, open- source robotics, and (2) a fast fabrication technique for analytical devices among others. Using the robotics of a 3D printer, a mass spectrometry-based reaction screening device was built as a low- cost, modest throughput alternative to expensive, very fast systems. Using the 3D printer for fabrication, ion mobility devices were fabricated. Fundamental studies of the motion of ions in these devices were performed in addition to applications of ion mobility-mass spectrometry using a 3D printed drift tube ion mobility spectrometer.</p><p><br></p><p>With only simple modification, 3D printer kits provide nearly all the necessary parts for a functional reaction screening device. Replacing the hotend assembly with custom parts to hold a syringe, precise volumes of reaction mixtures can be dispensed, and high voltage applied to the needle for direct analysis of solutions by mass spectrometry. Direct analysis of reaction mixtures in a 96-well microtiter plates was completed in approximately 105 minutes (~65 seconds per reaction mixture, including washing of syringe). Following analysis, product distributions derived from the electrospray mass spectra were represented as heatmaps and optimum reaction conditions were determined. Using low-cost, open-source hardware, a modest throughput for reaction screening could be achieved using electrospray ionization mass spectrometry.</p><p><br></p><p>The manipulation of ions at reduced pressures is very well understood, whereas the efficient manipulation of ions at atmospheric pressure is far less understood. Using 3D printing, multiple iterations of atmospheric pressure drift tube ion mobility spectrometers were fabricated with one and two turns in the drift path. Optimum electrode geometries for ion transmission and resolution were determined by both simulation and experiment. Racetrack effects, where ions on the inside of turns have a shorter path than ions on the outside, were determined to be highly detrimental to resolving power. Drift tubes with two turns in opposite directions (a chicane) corrected for racetrack effects and had only marginally poorer resolving power than a straight drift tube. Additionally, ion intensities were nearly identical between optimized straight and turned ion paths, showing that these manipulations can be done with high efficiency. The focusing of ions at reduced pressure using RF ion funnels at reduced pressure can have nearly 100 percent transmission. At atmospheric pressure, RF fields are not nearly as efficient at focusing ions. By using non-uniform DC fields at atmospheric pressure, ions can be focused, but not nearly to the extent as at reduced pressure.</p><p><br></p><div><div><div><p>The coupling of atmospheric pressure drift tube ion mobility with ion trap mass spectrometry is inefficient due to the mismatch in duty cycle between the two instruments. For this reason, increasing the amount of data collected from a single experiment is of high importance. Fourier transform ion mobility increases the duty cycle from less than 1% to 25%. When ions are fragmented in the mass spectrometer, they maintain the frequency characteristic of the precursor. Therefore, ions can be fragmented without isolation in the ion trap (reducing duty cycle further) and related precursors and product ions identified through their drift time. Two-dimensional tandem mass spectrometry is a method to collect all tandem mass spectrometry information in a single scan. When coupled with ion mobility, this data can be used to generate functional group- specific ion mobility spectra where ion intensity is measured along a precursor or neutral loss scan line. This was demonstrated for a lipid sample in which head-group specific ion mobility spectra were obtained using head-group specific precursor and neutral loss scan lines.</p></div></div></div>

Improved analytical methods using novel cleanup techniques and inexpensive instrumentation for the determination of residue estrogens in municipal wastewater and swine lagoon wastewater have been developed. Presented approaches are less expensive, less time consuming, yet produce comparable detection limits and extraction efficiencies to existing methods. Chapter I provides an overview on environmental estrogens. Chapter II describes a novel method to quantify five estrogens including estriol, estrone, 17alpha-estradiol, 17beta-estradiol, and 17alpha-ethynylestradiol in influent and effluent municipal wastewater. The method includes sample preparation using solid-phase extraction followed by a “QuEChERS” cleanup, dansylation and LC/MS/MS detection. Hydrophilic-lipophilic balance solid phase extraction (SPE) was used for sample preconcentration and the extract was cleaned up using a dispersive SPE method using MgSO4, PSA and C-18. The resulting extract was then derivatized with dansyl chloride. Separation was achieved on a C-18 column and quantification was accomplished in the positive ion mode using multiple reaction monitoring. The method is capable of detecting below 1 ng/L. Chapter III describes improved approaches to quantify five estrogens and two conjugates, Estrone 3-glucuronide and beta-Estradiol 3-sulfate, in swine lagoon wastewater and storm water runoff. A considerable residue was collected when lagoon wastewater samples were centrifuged therefore both resulting residues and aqueous portions were analyzed separately. Analysis of the aqueous portions was carried out using a similar approach to the method described in Chapter II. However, a simple test-tube liquid-liquid extraction was used as an additional sample clean-up step. A modified QuEChERS method was utilized to efficiently extract the target analytes in the residue. Methods have 0.9 – 2 ng/L detection limits. Chapter IV describes an approach to quantify residue estrogens in municipal wastewater using a comprehensive two-dimensional gas chromatograph (GCxGC). This method requires no further cleanups after SPE and has detection limits ranging from 1.4 – 22.2 ng/L. All presented methods use relatively small initial sample volumes and produce negligible matrix interferences. The developed methods were validated by performing mini surveys on the estrogen levels in environmental aqueous matrices in north Mississippi.

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