Este trabalho foi apoiado pelas Ciências Naturais e Council of Canada Equipamento, Descoberta e Discovery Accelerator Grants Pesquisa de Engenharia adjudicados a JMBNRB reconhece o apoio da Carnegie Institution of Washington programa de bolsas de pós-doutoramento. Stephen Elardo também é agradeceu por sua assistência antes de filmar com a imprensa pistão-cilindro no Laboratório de Geofísica.

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Os resultados dos experimentos livres de inclusão realizadas utilizando os protocolos descritos aqui foram previamente comparados com os dados da literatura em referências 29 (Os, IR, Au), 30 (Re, Au) e 31 (Pt). Pt é mais instrutivo para demonstrar a utilidade de run-livre de produtos de inclusão. Para as experiências executadas a baixa f ó 2, Ertel et ai. 48 inclusões atribuído a uma origem estável e, portanto, redução de dados restrita...

Acreção terrestre é pensado para ter ocorrido como uma série de colisões entre planetesimais com uma composição de massa condritos, que termina numa fase de gigante impacto pensou responsável pela formação de lua 1,2. Aquecimento da terra proto-o por impactos e o decaimento de isótopos de vida curta é suficiente para provocar a fusão e a grande formação de um magma oceano ou lagoas através do qual densa rica em Fe metálicos fundidos podia descer. Ao alcançar a base do oceano de magma, fundidos metálicos encontrar um limite reológico, tenda, e submeter-se o equilíbrio de silicato de metal final antes de, eventualmente, descendo através do manto sólido para o núcleo 2 em crescimento. A eventual comunicação química entre o metal e as fases de silicato como material metálico fundido atravessa a parte sólida do manto é pensado para ser impedido devido ao tamanho grande e rápida descida de diapirs de metal 3. Esta diferenciação primária da Terra em um núcleo metálico e mant silicatole é revelado hoje por ambas as observações geofísicas e geoquímicas 4-6. Interpretação destas observações para proporcionar condições plausíveis para o equilíbrio de silicato de metal na base de um oceano de magma, no entanto, requer uma base de dados adequada dos resultados experimentais. O manto superior primitivo (PUM) é um reservatório hipotético compreendendo o resíduo de silicato de formação de núcleo e sua composição reflete, portanto, o comportamento de elementos traço durante equilíbrio silicato-metal. Oligoelementos são distribuídos entre o metal eo silicato derrete durante a segregação núcleo com base na sua afinidade geoquímica. A magnitude de uma preferência de elementos para a fase de metal pode ser descrita pelo coeficiente de partição de metal-silicato <img alt="Equação 1" src="/files/ftp_upload/52725/52725eq1.jpg" /><img alt="Equação 2" src="/files/ftp_upload/52725/52725eq2.jpg" /> (1) Onde <img alt="Equação 3" src="/files/ftp_upload/52725/52725eq3.jpg" /> e <img alt="Equação 4" src="/files/ftp_upload/52725/52725eq4.jpg" /> denota a concentração do elemento i, em metal e silicato de derreter respectivamente. Valores de <img alt="Equação 5" src="/files/ftp_upload/52725/52725eq5.jpg" /> &gt; 1 indicam siderophile comportamento (-loving de ferro) e aqueles &lt;1 lithophile (-loving rock) comportamento. Estimativas da composição mostra PUM que sidérophile elementos estão esgotados em relação ao chondrites 7, geralmente consideradas como representativas da composição química da Terra 6,8. Este esgotamento é devido ao sequestro de elementos siderófilos pelo núcleo, e por elementos refractários sua magnitude deve refletir diretamente os valores de <img alt="Equação 5" src="/files/ftp_upload/52725/52725eq5.jpg" /> . Experimentos em laboratório, portanto, procurar para determinar os valores de <img alt="Equação 5" src="/files/ftp_upload/52725/52725eq5.jpg" /> ao longo de um raESL de pressão (P), a temperatura (T) e fugacidade oxigénio (O2 f) condições que são relevantes para a segregação de metal a partir da base de um oceano de magma. Os resultados destas experiências pode então ser usada para delinear as regiões de P - t - f O2 espaço que são compatíveis com a abundância de PUM de múltiplos elementos siderófilos (por exemplo, 9-11). As altas pressões e temperaturas relevantes para um cenário de oceano de magma pode ser recriada em laboratório usando um pistão-cilindro ou prensa multi-bigorna. O aparelho de embolo-cilindro permite o acesso a uma pressão moderada (~ 2 GPa) e temperatura elevada (~ 2573 K) condições, mas permite que grandes volumes de amostra e uma variedade de materiais de cápsula que será utilizada facilmente. A taxa de arrefecimento rápido também permite a têmpera de uma gama de composições de fusão de silicato para um copo, simplificando assim a interpretação textural dos subprodutos de execução.O aparelho multi-bigorna emprega tipicamente volumes de amostras menores, mas com desenhos de montagem adequados podem atingir pressões de até ~ 27 GPa e temperaturas de ~ 3.000 K. O uso desses métodos tem permitido particionamento de dados para muitos dos moderadamente e levemente siderófilos elementos para ser reuniu mais de uma grande variedade de P - condições T. As previsões da composição PUM com base nesses dados sugerem equilíbrio silicato de metal ocorreu em condições médias de pressão e temperatura em excesso de ~ 29 GPa e 3000 K, respectivamente, embora os valores exactos dependem modelo. A fim de explicar a abundância de elementos sensíveis à PUM certo redox (por exemplo, V, Cr) a f O 2 também é pensado para evoluir durante acréscimo de ~ 4-2 unidades log abaixo desse imposto pela co-existente de ferro e wustite (FeO ) em condições PT equivalentes (o tampão de ferro wustite) 12. Apesar da abundância de PUM mquaisquer elementos siderófilos pode ser explicada pelo equilíbrio silicato de metal na base de um oceano de magma profundo, revelou-se difícil avaliar se esta situação também se aplica aos elementos mais altamente siderophile (HSES). A extrema afinidade dos HSES para o ferro em metal indicado pela baixa pressão (P ~ 0.1 MPa) e temperatura (T &lt;1.673 K) experimentos sugere o silicato de terra deve ser fortemente empobrecido nestes elementos. As estimativas do teor de SMS para PUM, no entanto, indicam apenas uma moderada depleção em relação ao condrito (Figura 1). Uma solução comumente posta ao excesso HSE aparente é que a Terra experimentou um fim de acreção de material condritos subseqüente ao core-formação 13. Este material late-acrescidos teria misturado com o PUM e concentrações elevadas de SMS, mas teve um efeito insignificante sobre os elementos mais abundantes. Alternativamente, foi sugerido que a natureza extremamente siderophile de HSES indicado por baixo P </em&gt; - Experimentos T não persiste para as altas condições PT presentes durante core-formação 14,15. A fim de testar estas hipóteses, as experiências devem ser realizados para determinar a solubilidade e de metal-silicato de particionamento HSES em condições adequadas. Contaminação da parte de silicato de subprodutos funcionamento extinta em muitos estudos anteriores no entanto, tem complicado a análise do produto run e obscureceram os verdadeiros coeficientes de partição para HSES entre o metal eo derrete silicato. Em experiências de separação onde os HSES estão presentes em níveis de concentração adequadas para a natureza, a preferência extremo destes elementos de metal de Fe-impede a sua medição na massa fundida de silicato. Para contornar este problema, as medições de solubilidade são feitas em que o silicato de fusão está saturado na HSE de interesse e os valores de <img alt="Equação 5" src="/files/ftp_upload/52725/52725eq5.jpg" /> são calculados utilizando o formalismo de Borisov etal. 16. Subprodutos executados silicato extinta a partir de experimentos de solubilidade de SMS realizadas em condições de redução, no entanto, muitas vezes exibem evidência de contaminação por disperso HSE ± Fe inclusões 17. Apesar de a quase omnipresença destas inclusões em baixo f O 2 experimentos contendo Pt, Ir, Os, Re e Ru, (por exemplo, 18 - 27), existe uma variabilidade notável entre os estudos em sua apresentação textural; comparar, por exemplo, faz referência 22 e 26. Embora tenha sido demonstrado que as inclusões podem formar uma fase que são estáveis ​​nas condições de execução de uma experiência 28, isto não exclui a formação de inclusões que a amostra é temperada. A incerteza que rodeia a origem de inclusões torna o tratamento dos resultados analíticos difícil, e levou a ambiguidade sobre a verdadeira solubilidade reduzida em HSES silicato derrete. Run-livre de produtos de inclusão são necessários para avaliarque estudos têm adotado uma abordagem analítica que produz concentrações HSE dissolvidos precisos. Um progresso considerável na supressão da formação de inclusões de metal-em condições redutoras foi agora demonstrada em experiências que utilizam um aparelho de embolo-cilindro, em que o desenho da amostra foi alterada a partir de estudos anteriores por adição ou Au ou Si para os materiais de partida 29-31. A adição de Si elementar ou Au para os materiais de partida alteram a evolução geometria da amostra ou f S 2 da experiência, respectivamente. Estes métodos destinam-se a suprimir a formação de inclusões de metal através da alteração da temporização da HSE na contra-difusão redução amostra, e são discutidos em Bennett et ai. 31. Ao contrário de algumas tentativas anteriores para limpar a fusão de silicato de inclusões, tais como equilíbrio assistida mecanicamente eo pistão-cilindro centrifugação, o presente protocolo pode ser implementado sem appar especializadaatus e é adequado para experimentos de alta PT. Descrito em pormenor aqui é uma abordagem baseada êmbolo-cilindro para determinar a solubilidade de Re, Os, Ir, Ru, Pt e Au, em massa fundida de silicato a alta temperatura (&gt; 1873 K), 2 GPa e uma f ó 2 semelhante ao da o buffer de-ferro wustite. Aplicação de um projeto experimental semelhante pode também ser bem sucedida em experimentos de SMS em outras pressões, fornecendo as relações de fase necessários, molhando propriedades e relacionamentos cinéticos persistem as condições escolhidas. Os dados existentes no entanto, são insuficientes para prever se a nossa concepção da amostra será bem sucedida a pressões correspondentes a um oceano de magma profundo. Também é delineada uma abordagem geral utilizada para determinar elemento moderadamente e levemente siderophile (MSE e SSE respectivamente) particionamento usando um dispositivo multi-bigorna. Extensão do conjunto de dados livre de inclusão para HSES a alta pressão é susceptível de empregar métodos multi-bigorna semelhantes. Trajeséter, estes procedimentos proporcionam um meio para limitar tanto as condições de núcleo-segregação e as fases de acreção terrestre.

<table border="0" cellpadding="0" cellspacing="0">
	<tbody>
		<tr>
			<td>G10 Epoxy/Fiberglass Sheet</td>
			<td>Accurate plastics, Inc.</td>
			<td>GEES.020N.3648</td>
			<td></td>
		</tr>
		<tr>
			<td>Powdered starting materials- -Oxides, metals, carbonates</td>
			<td>Alfa Aesar</td>
			<td>Specific to desired experiment</td>
			<td></td>
		</tr>
		<tr>
			<td>Castable 2-part MgO ceramic</td>
			<td>Aremco</td>
			<td>Ceramcast - 584</td>
			<td></td>
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		<tr>
			<td>PTFE Dry Lubricant</td>
			<td>Camie-Campbell</td>
			<td>2000 TFE-Coat</td>
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			<td>Graphite resistance heaters</td>
			<td>Carbone of America (Now owned by Mersen USA)</td>
			<td>Custom Order</td>
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			<td>Barium Carbonate</td>
			<td>Chemical Products Corporation</td>
			<td>Custom Order</td>
			<td>Calcined free-flowing (CFF) grade</td>
		</tr>
		<tr>
			<td>C-Type Thermocouple Wire (W26%Re, W5%Re)</td>
			<td>Concept Alloys</td>
			<td>N/A</td>
			<td>~0.25 mm diameter is suitable for most experiments</td>
		</tr>
		<tr>
			<td>Zirconia Cement</td>
			<td>Cotronics; Resbond 940 2-part cement</td>
			<td>N/A</td>
			<td>Use 100 parts powder for every 25 to 28 parts activator</td>
		</tr>
		<tr>
			<td>Polyvinyl Acetate (PVA) Glue</td>
			<td>e.g Bostik</td>
			<td>N/A</td>
			<td>Often sold as &#39;white glue&#39;</td>
		</tr>
		<tr>
			<td>Cyanoacrylate Glue</td>
			<td>e.g Krazy Glue/Loctite</td>
			<td>N/A</td>
			<td></td>
		</tr>
		<tr>
			<td>Piston cylinder pressure vessel and WC piston</td>
			<td>Hi-Quality Carbide Tooling Inc.</td>
			<td>Custom Order</td>
			<td></td>
		</tr>
		<tr>
			<td>Silica Glass Tubing</td>
			<td>Quartz Plus</td>
			<td>Custom Order</td>
			<td></td>
		</tr>
		<tr>
			<td>Crushable ZrO2 tubes</td>
			<td>Saint-Gobain</td>
			<td>Custom Order</td>
			<td></td>
		</tr>
		<tr>
			<td>Crushable MgO rods and tubes</td>
			<td>Saint-Gobain</td>
			<td>Custom Order</td>
			<td></td>
		</tr>
		<tr>
			<td>WC cubes for multi-anvil experiments</td>
			<td>Tungaloy</td>
			<td>Custom Order</td>
			<td>Cubes are grade-F WC alloy</td>
		</tr>
		<tr>
			<td>Single hole alumina tube for multi-anvil thermocouple</td>
			<td>Vesuvius McDanel</td>
			<td>AXS071730-04-06</td>
			<td></td>
		</tr>
		<tr>
			<td>4-hole alumina tube for piston cylinder thermocouple</td>
			<td>Vesuvius McDanel</td>
			<td>AXF1159--07-12&#160;</td>
			<td></td>
		</tr>
		<tr>
			<td>4-hole alumina tube for multi-anvil thermocouple</td>
			<td>Vesuvius McDanel</td>
			<td>AXF1159-04-06</td>
			<td></td>
		</tr>
	</tbody>
</table>

metal-silicate partitioning at high pressure and temperature: experimental methods and a protocol to suppress highly siderophile element inclusions

Estimates of the primitive upper mantle (PUM) composition reveal a depletion in many of the siderophile (iron-loving) elements, thought to result from their extraction to the core during terrestrial accretion. Experiments to investigate the partitioning of these elements between metal and silicate melts suggest that the PUM composition is best matched if metal-silicate equilibrium occurred at high pressures and temperatures, in a deep magma ocean environment. The behavior of the most highly siderophile elements (HSEs) during this process however, has remained enigmatic. Silicate run-products from HSE solubility experiments are commonly contaminated by dispersed metal inclusions that hinder the measurement of element concentrations in the melt. The resulting uncertainty over the true solubility and metal-silicate partitioning of these elements has made it difficult to predict their expected depletion in PUM. Recently, several studies have employed changes to the experimental design used for high pressure and temperature solubility experiments in order to suppress the formation of metal inclusions. The addition of Au (Re, Os, Ir, Ru experiments) or elemental Si (Pt experiments) to the sample acts to alter either the geometry or rate of sample reduction respectively, in order to avoid transient metal oversaturation of the silicate melt. This contribution outlines procedures for using the piston-cylinder and multi-anvil apparatus to conduct solubility and metal-silicate partitioning experiments respectively. A protocol is also described for the synthesis of uncontaminated run-products from HSE solubility experiments in which the oxygen fugacity is similar to that during terrestrial core-formation. Time-resolved LA-ICP-MS spectra are presented as evidence for the absence of metal-inclusions in run-products from earlier studies, and also confirm that the technique may be extended to investigate Ru. Examples are also given of how these data may be applied.

Os exemplos a seguir e centrar o debate sobre experimentos para determinar HSE solubilidade em silicato funde a baixa f O 2. Para obter exemplos detalhados de como MSE e particionamento de dados SSE a partir de experimentos multi-bigorna pode ser usado para restringir o P - T - f O 2 condições de segregação de metal core, o leitor é remetido para referências. 9 - 11 Figura 7B-D mostra de volta imagens de elétrons dispersadas de ...

Watch this Scientific Journal Video about Metal-silicate Partitioning at High Pressure and Temperature: Experimental Methods and a Protocol to Suppress Highly Siderophile Element Inclusions at JoVE.co

Metal-silicate Partitioning at High Pressure and Temperature: Experimental Methods and a Protocol to Suppress Highly Siderophile Element Inclusions

We present a procedure to determine the metal-silicate partitioning of siderophile elements, emphasizing techniques that suppress the formation of metal inclusions in experiments for the noble metals. The results of these experiments are used to demonstrate the effect of core-formation on the highly siderophile element composition of the mantle.

Partitioning Metal-silicato em alta pressão e temperatura: Métodos experimentais e um protocolo para suprimir Altamente sidérophile Elemento Inclusões

Estimates of the primitive upper mantle (PUM) composition reveal a depletion in many of the siderophile (iron-loving) elements, thought to result from ...

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12.4K visualizações.  University of Toronto. We present a procedure to determine the metal-silicate partitioning of siderophile elements, emphasizing techniques that suppress the formation of metal inclusions in experiments for the noble metals. The results of these experiments are used to demonstrate the effect of core-formation on the highly siderophile element composition of the mantle.

Vídeo: Metal-silicate Partitioning at High Pressure and Temperature: Experimental Methods and a Protocol to Suppress Highly Siderophile Element Inclusions

High-pressure Sapphire Cell for Phase Equilibria Measurements of CO2/Organic/Water Systems

The high pressure sapphire cell apparatus was constructed to visually determine the composition of multiphase systems without physical sampling. Specifically, the sapphire cell enables visual data collection from multiple loadings to solve a set of material balances to precisely determine phase composition. Ternary phase diagrams can then be established to determine the proportion of each component in each phase at a given condition. In principle, any ternary system can be studied although ternary systems (gas-liquid-liquid) are the specific examples discussed herein. For instance, the ternary THF-Water-CO2 system was studied at 25 and 40&#160;&#176;C and is described herein. Of key importance, this technique does not require sampling. Circumventing the possible disturbance of the system equilibrium upon sampling, inherent measurement errors, and technical difficulties of physically sampling under pressure is a significant benefit of this technique. Perhaps as important, the sapphire cell also enables the direct visual observation of the phase behavior. In fact, as the CO2 pressure is increased, the homogeneous THF-Water solution phase splits at about 2 MPa. With this technique, it was possible to easily and clearly observe the cloud point and determine the composition of the newly formed phases as a function of pressure.
The data acquired with the sapphire cell technique can be used for many applications. In our case, we measured swelling and composition for tunable solvents, like gas-expanded liquids, gas-expanded ionic liquids and Organic Aqueous Tunable Systems (OATS)1-4. For the latest system, OATS, the high-pressure sapphire cell enabled the study of (1) phase behavior as a function of pressure and temperature, (2) composition of each phase (gas-liquid-liquid) as a function of pressure and temperature and (3) catalyst partitioning in the two liquid phases as a function of pressure and composition. Finally, the sapphire cell is an especially effective tool to gather accurate and reproducible measurements in a timely fashion.

High-pressure Sapphire Cell for Phase Equilibria Measurements of CO2/Organic/Water Systems

The high pressure sapphire cell apparatus is a unique tool to study, without sampling, phase behavior under a wide range of pressures. Using a cathetometer, very precise volume measurements can be recorded to measure liquid expansion and phase composition. Thus, this synthetic method enables the study of (1) phase equilibria of multi-component mixtures and (2) the partition behavior of catalyst or model compounds as a function of pressure.

Sapphire celular de alta pressão para medições de Equilíbrio de Fases de CO<sub&gt; 2</sub&gt; / Orgânicos / Sistemas de Água

The high pressure sapphire cell apparatus was constructed to visually determine the composition of multiphase systems without physical sampling. ...

Química

Ethylene Polymerizations Using Parallel Pressure Reactors and a Kinetic Analysis of Chain Transfer Polymerization

We demonstrate a method for high-throughput catalyst screening using a parallel pressure reactor starting from the initial synthesis of a nickel &#945;-diimine ethylene polymerization catalyst. Initial polymerizations with the catalyst lead to optimized reaction conditions, including catalyst concentration, ethylene pressure and reaction time. Using gas-uptake data for these reactions, a procedure to calculate the initial rate of propagation (kp) is presented. Using the optimized conditions, the ability of the nickel &#945;-diimine polymerization catalyst to undergo chain transfer with diethylzinc (ZnEt2) during ethylene polymerization was investigated. A procedure to assess the ability of the catalyst to undergo chain transfer (from molecular weight and 13C NMR data), calculate the degree of chain transfer, and calculate chain transfer rates (ke) is presented.

A protocol for the high-throughput analysis of polymerization catalyst, chain transfer polymerizations, polyethylene characterization, and reaction kinetic analysis is presented.

Polimerizações etileno utilizando reatores de pressão paralelas e uma análise cinética da cadeia de transferência de Polimerização

We demonstrate a method for high-throughput catalyst screening using a parallel pressure reactor starting from the initial synthesis of a nickel ...

Preparation of Carbon Nanosheets at Room Temperature

Amphiphilic molecules equipped with a reactive, carbon-rich "oligoyne" segment consisting of conjugated carbon-carbon triple bonds self-assemble into defined aggregates in aqueous media and at the air-water interface. In the aggregated state, the oligoynes can then be carbonized under mild conditions while preserving the morphology and the embedded chemical functionalization. This novel approach provides direct access to functionalized carbon nanomaterials. In this article, we present a synthetic approach that allows us to prepare hexayne carboxylate amphiphiles as carbon-rich siblings of typical fatty acid esters through a series of repeated bromination and Negishi-type cross-coupling reactions. The obtained compounds are designed to self-assemble into monolayers at the air-water interface, and we show how this can be achieved in a Langmuir trough. Thus, compression of the molecules at the air-water interface triggers the film formation and leads to a densely packed layer of the molecules. The complete carbonization of the films at the air-water interface is then accomplished by cross-linking of the hexayne layer at room temperature, using UV irradiation as a mild external stimulus. The changes in the layer during this process can be monitored with the help of infrared reflection-absorption spectroscopy and Brewster angle microscopy. Moreover, a transfer of the carbonized films onto solid substrates by the Langmuir-Blodgett technique has enabled us to prove that they were carbon nanosheets with lateral dimensions on the order of centimeters.

We present the synthesis of an amphiphilic hexayne and its use in the preparation of carbon nanosheets at the air-water interface from a self-assembled monolayer of these reactive, carbon-rich molecular precursors.

Preparação de Nanofolhas de Carbono à Temperatura Ambiente

Amphiphilic molecules equipped with a reactive, carbon-rich "oligoyne" segment consisting of conjugated carbon-carbon triple bonds self-assemble into ...

Protocol for the Synthesis of Ortho-trifluoromethoxylated Aniline Derivatives

Molecules bearing trifluoromethoxy (OCF3) group often show desired pharmacological and biological properties. However, facile synthesis of trifluoromethoxylated aromatic compounds remains a formidable challenge in organic synthesis. Conventional approaches often suffer from poor substrate scope, or require use of highly toxic, difficult-to-handle, and/or thermally labile reagents. Herein, we report a user-friendly protocol for the synthesis of methyl 4-acetamido-3-(trifluoromethoxy)benzoate using 1-trifluoromethyl-1,2-benziodoxol-3(1H)-one (Togni reagent II). Treating methyl 4-(N-hydroxyacetamido)benzoate (1a) with Togni reagent II in the presence of a catalytic amount of cesium carbonate (Cs2CO3) in chloroform at RT afforded methyl 4-(N-(trifluoromethoxy)acetamido)benzoate (2a). This intermediate was then converted to the final product methyl 4-acetamido-3-(trifluoromethoxy)benzoate (3a) in nitromethane at 120 &#176;C. This procedure is general and can be applied to the synthesis of a broad spectrum of ortho-trifluoromethoxylated aniline derivatives, which could serve as useful synthetic building blocks for the discovery and development of new pharmaceuticals, agrochemicals, and functional materials.

Protocol for the Synthesis of Ortho-trifluoromethoxylated Aniline Derivatives

An operationally simple procedure for the synthesis of ortho-trifluoromethoxylated aniline derivatives via a two-step sequence of O-trifluoromethylation of N-aryl-N-hydroxyacetamide followed by thermally induced intramolecular OCF3-migration is reported.

Protocolo para a Síntese de Derivados de Anilina Orto-trifluorometoxilados

Molecules bearing trifluoromethoxy (OCF3) group often show desired pharmacological and biological properties. However, facile synthesis of ...

Rapid High-throughput Species Identification of Botanical Material Using Direct Analysis in Real Time High Resolution Mass Spectrometry

We demonstrate that direct analysis in real time-high resolution mass spectrometry can be used to produce mass spectral profiles of botanical material, and that these chemical fingerprints can be used for plant species identification. The mass spectral data can be acquired rapidly and in a high throughput manner without the need for sample extraction, derivatization or pH adjustment steps. The use of this technique bypasses challenges presented by more conventional techniques including lengthy chromatography analysis times and resource intensive methods. The high throughput capabilities of the direct analysis in real time-high resolution mass spectrometry protocol, coupled with multivariate statistical analysis processing of the data, provide not only class characterization of plants, but also yield species and varietal information. Here, the technique is demonstrated with two psychoactive plant products, Mitragyna speciosa (Kratom) and Datura (Jimsonweed), which were subjected to direct analysis in real time-high resolution mass spectrometry followed by statistical analysis processing of the mass spectral data. The application of these tools in tandem enabled the plant materials to be rapidly identified at the level of variety and species.

A method for species identification of botanical material by direct analysis in real time-high resolution mass spectrometry and multivariate statistical analysis is presented.

Rápida de alta capacidade: Identificação de Espécies de material botânico Usando Direct Análise em Tempo Real alta resolução Espectrometria de Massa

We demonstrate that direct analysis in real time-high resolution mass spectrometry can be used to produce mass spectral profiles of botanical material, ...

High Pressure Single Crystal Diffraction at PX^2

In this report we describe detailed procedures for carrying out single crystal X-ray diffraction experiments with a diamond anvil cell (DAC) at the GSECARS 13-BM-C beamline at the Advanced Photon Source. The DAC program at 13-BM-C is part of the Partnership for Extreme Xtallography (PX^2) project. BX-90 type DACs with conical-type diamond anvils and backing plates are recommended for these experiments. The sample chamber should be loaded with noble gas to maintain a hydrostatic pressure environment. The sample is aligned to the rotation center of the diffraction goniometer. The MARCCD area detector is calibrated with a powder diffraction pattern from LaB6. The sample diffraction peaks are analyzed with the ATREX software program, and are then indexed with the RSV software program. RSV is used to refine the UB matrix of the single crystal, and with this information and the peak prediction function, more diffraction peaks can be located. Representative single crystal diffraction data from an omphacite (Ca0.51Na0.48)(Mg0.44Al0.44Fe2+0.14Fe3+0.02)Si2O6 sample were collected. Analysis of the data gave a monoclinic lattice with P2/n space group at 0.35 GPa, and the lattice parameters were found to be: a = 9.496 &#177;0.006 &#197;, b = 8.761 &#177;0.004 &#197;, c = 5.248 &#177;0.001 &#197;, &#946; = 105.06 &#177;0.03&#186;, &#945; = &#947; = 90&#186;.

In this report, we describe detailed procedures for carrying out single crystal X-ray diffraction experiments with a diamond anvil cell at the GSECARS 13-BM-C beamline at the Advanced Photon Source. ATREX and RSV programs are used to analyze the data.

Alta Pressão Único Difração de Cristal no PX ^ 2

In this report we describe detailed procedures for carrying out single crystal X-ray diffraction experiments with a diamond anvil cell (DAC) at the ...

Non-equilibrium Microwave Plasma for Efficient High Temperature Chemistry

A flowing microwave plasma based methodology for converting electric energy into internal and/or translational modes of stable molecules with the purpose of efficiently driving non-equilibrium chemistry is discussed. The advantage of a flowing plasma reactor is that continuous chemical processes can be driven with the flexibility of startup times in the seconds timescale. The plasma approach is generically suitable for conversion/activation of stable molecules such as CO2, N2 and CH4. Here the reduction of CO2 to CO is used as a model system: the complementary diagnostics illustrate how a baseline thermodynamic equilibrium conversion can be exceeded by the intrinsic non-equilibrium from high vibrational excitation. Laser (Rayleigh) scattering is used to measure the reactor temperature and Fourier Transform Infrared Spectroscopy (FTIR) to characterize in situ internal (vibrational) excitation as well as the effluent composition to monitor conversion and selectivity.

This article describes a flowing microwave reactor that is used to drive efficient non-equilibrium chemistry for the application of conversion/activation of stable molecules such as CO2, N2 and CH4. The goal of the procedure described here is to measure the in situ gas temperature and gas conversion.

Plasma de microondas sem equilíbrio para química de alta temperatura eficiente

A flowing microwave plasma based methodology for converting electric energy into internal and/or translational modes of stable molecules with the purpose ...

A Straightforward Method for Glucosinolate Extraction and Analysis with High-pressure Liquid Chromatography (HPLC)

Glucosinolates are a well-studied and highly diverse class of natural plant compounds. They play important roles in plant resistance, rapeseed oil quality, food flavoring, and human health. The biological activity of glucosinolates is released upon tissue damage, when they are mixed with the enzyme myrosinase. This results in the formation of pungent and toxic breakdown products, such as isothiocyanates and nitriles. Currently, more than 130 structurally different glucosinolates have been identified. The chemical structure of the glucosinolate is an important determinant of the product that is formed, which in turn determines its biological activity. The latter may range from detrimental (e.g., progoitrin) to beneficial (e.g., glucoraphanin). Each glucosinolate-containing plant species has its own specific glucosinolate profile. For this reason, it is important to correctly identify and reliably quantify the different glucosinolates present in brassicaceous leaf, seed, and root crops or, for ecological studies, in their wild relatives. Here, we present a well-validated, targeted, and robust method to analyze glucosinolate profiles in a wide range of plant species and plant organs. Intact glucosinolates are extracted from ground plant materials with a methanol-water mixture at high temperatures to disable myrosinase activity. Thereafter, the resulting extract is brought onto an ion-exchange column for purification. After sulfatase treatment, the desulfoglucosinolates are eluted with water and the eluate is freeze-dried. The residue is taken up in an exact volume of water, which is analyzed by high-pressure liquid chromatography (HPLC) with a photodiode array (PDA) or ultraviolet (UV) detector. Detection and quantification are achieved by conducting comparisons of the retention times and UV spectra of commercial reference standards. The concentrations are calculated based on a sinigrin reference curve and well-established response factors. The advantages and disadvantages of this straightforward method, when compared to faster and more technologically advanced methods, are discussed here.

A Straightforward Method for Glucosinolate Extraction and Analysis with High-pressure Liquid Chromatography HPLC

Here, we describe in great detail an established and robust protocol for the extraction of glucosinolates from ground plant materials. After an on-column sulfatase treatment of the extracts, the desulfoglucosinolates are eluted and analyzed by high-pressure liquid chromatography.

Um método simples para glucosinolatos Extracção e análise com cromatografia líquida de alta pressão (HPLC)

Glucosinolates are a well-studied and highly diverse class of natural plant compounds. They play important roles in plant resistance, rapeseed oil ...

A Convenient Method for Extraction and Analysis with High-Pressure Liquid Chromatography of Catecholamine Neurotransmitters and Their Metabolites

The extraction and analysis of catecholamine neurotransmitters in biological fluids is of great importance in assessing nervous system function and related diseases, but their precise measurement is still a challenge. Many protocols have been described for neurotransmitter measurement by a variety of instruments, including high-pressure liquid chromatography (HPLC). However, there are shortcomings, such as complicated operation or hard-to-detect multiple targets, which cannot be avoided, and presently, the dominant analysis technique is still HPLC coupled with sensitive electrochemical or fluorimetric detection, due to its high sensitivity and good selectivity. Here, a detailed protocol is described for the pretreatment and detection of catecholamines with high pressure liquid chromatography with electrochemical detection (HPLC-ECD) in real urine samples of infants, using electrospun composite nanofibers composed of polymeric crown ether with polystyrene as adsorbent, also known as the packed-fiber solid phase extraction (PFSPE) method. We show how urine samples can be easily precleaned by a nanofiber-packed solid phase column, and how the analytes in the sample can be rapidly enriched, desorbed, and detected on an ECD system. PFSPE greatly simplifies the pretreatment procedures for biological samples, allowing for decreased time, expense, and reduction of the loss of targets. 
Overall, this work illustrates a simple and convenient protocol for solid-phase extraction coupled to an HPLC-ECD system for simultaneous determination of three monoamine neurotransmitters (norepinephrine (NE), epinephrine (E), dopamine (DA)) and two of their metabolites (3-methoxy-4-hydroxyphenylglycol (MHPG) and 3,4-dihydroxy-phenylacetic acid (DOPAC)) in infants' urine. The established protocol was applied to assess the differences of urinary catecholamines and their metabolites between high-risk infants with perinatal brain damage and healthy controls. Comparative analysis revealed a significant difference in urinary MHPG between the two groups, indicating that the catecholamine metabolites may be an important candidate marker for early diagnosis of cases at risk for brain damage in infants.

We present a convenient solid-phase extraction coupled to high-pressure liquid chromatography (HPLC) with electrochemical detection (ECD) for simultaneous determination of three monoamine neurotransmitters and two of their metabolites in infants' urine. We also identify the metabolite MHPG as a potential biomarker for the early diagnosis of brain damage for infants.

Um método conveniente para extração e análise com a cromatografia líquida de alta pressão de neurotransmissores catecolaminas e seus metabólitos

The extraction and analysis of catecholamine neurotransmitters in biological fluids is of great importance in assessing nervous system function and ...

Experimental Methods for Efficient Solar Hydrogen Production in Microgravity Environment

Long-term space flights and cis-lunar research platforms require a sustainable and light life-support hardware which can be reliably employed outside the Earth's atmosphere. So-called 'solar fuel' devices, currently developed for terrestrial applications in the quest for realizing a sustainable energy economy on Earth, provide promising alternative systems to existing air-revitalization units employed on the International Space Station (ISS) through photoelectrochemical water-splitting and hydrogen production. One obstacle for water (photo-) electrolysis in reduced gravity environments is the absence of buoyancy and the consequential, hindered gas bubble release from the electrode surface. This causes the formation of gas bubble froth layers in proximity to the electrode surface, leading to an increase in ohmic resistance and cell-efficiency loss due to reduced mass transfer of substrates and products to and from the electrode. Recently, we have demonstrated efficient solar hydrogen production in microgravity environment, using an integrated semiconductor-electrocatalyst system with p-type indium phosphide as the light-absorber and a rhodium electrocatalyst. By nanostructuring the electrocatalyst using shadow nanosphere lithography and thereby creating catalytic 'hot spots' on the photoelectrode surface, we could overcome gas bubble coalescence and mass transfer limitations and demonstrated efficient hydrogen production at high current densities in reduced gravitation. Here, the experimental details are described for the preparations of these nanostructured devices and further on, the procedure for their testing in microgravity environment, realized at the Bremen Drop Tower during 9.3 s of free fall.

Efficient solar-hydrogen production has recently been realized on functionalized semiconductor-electrocatalyst systems in a photoelectrochemical half-cell in microgravity environment at the Bremen Drop Tower. Here, we report the experimental procedures for manufacturing the semiconductor-electrocatalyst device, details of the experimental set-up in the drop capsule and the experimental sequence during free fall.

Métodos experimentais para a produção eficiente de hidrogênio solar em ambiente de microgravidade

Long-term space flights and cis-lunar research platforms require a sustainable and light life-support hardware which can be reliably employed outside the ...