The authors would like to acknowledge support from the Government of Canada's interdepartmental Program of Energy Research and Development, PERD 113, Petroleum Conversion for Cleaner Air. N.E.H would like to acknowledge her Natural Sciences and Engineering Research Council of Canada Visiting Fellowship.

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The authors have nothing to disclose.

A fim de atingir uma boa medição de H2S, este método emprega um interruptor Deans, backflushing e um detector de enxofre por quimioluminescência (SCD). Uma coluna de dimetilpolissiloxano é usada como a primeira coluna dimensão GC, e serve para retardar o movimento de hidrocarbonetos mais pesados ​​presentes na amostra, de modo que eles não contaminam a coluna trama. Este efeito é reforçado por um fresco (50 ° C) separação inicial. Gases de luz passam através da primeira coluna dimensão e sã...

Análise precisa do petróleo bruto é essencial para a indústria de petróleo e gás, como regulamentos e economia da saúde e segurança são funções de qualidade do óleo. A fim de proteger os transportadores de amostras em bruto, que é necessário para determinar as propriedades de amostras em bruto a desenvolver regulamentos de segurança para ser implementado no caso de uma libertação ou derrame. Em particular, a quantificação de sulfureto de hidrogénio (H2S) é importante, devido à sua elevada toxicidade em fase gasosa; exposições tão baixas quanto 100 ppm pode ser fatal (http://www.cdc.gov/niosh/idlh/7783064.html) 1,2. Dissolveu-se H 2 S em amostras em bruto é geralmente considerado para ser corrosivo 3,4, e pode desactivar os catalisadores utilizados para tratar o óleo 5-7. A remoção do H2S a partir de fluxos de petróleo bruto é ideal, mas sem um método para medir dissolvido H2S, é difícil de avaliar o sucesso dos tratamentos de remoção. Por estas razões, este protocolo foi desenvolvido para medir Dissolved H 2 S em amostras de petróleo bruto pesado, tais como areias petrolíferas canadenses crudes. Uma série de métodos convencionais existem para a quantificação de H 2 S em amostras de petróleo ou combustível com base mais leves, mas nenhum foi validado para uso com o petróleo mais pesado geralmente extraídos das areias betuminosas do Canadá. H 2 S e os mercaptanos são determinadas utilizando uma técnica de titulação por Universal Oil Products (UOP) 163 Método 8, mas este método sofre de inclinação do utilizador-interpretação que resulta da leitura manual das curvas de titulação. Instituto do Petróleo método 570 (IP) usa uma especialidade H 2 S analisador que aquece amostras de óleo combustível 9, e os benefícios de simplicidade e portabilidade, mas carece de precisão com amostras mais pesados ​​10. A Sociedade Americana de Testes e Materiais (ASTM) Método D5623 utiliza a cromatografia gasosa (GC) com resfriamento criogênico e detecção seletiva de enxofre para medir H2S em líquidos de petróleo leves11,12. Este padrão pode ser melhorada ao utilizar uma separação ambiente e também ser aplicado a óleos brutos pesados, pelo que foi utilizada como a base para o protocolo aqui discutido. GC é uma técnica muito utilizada para a análise de amostras de petróleo. As amostras são vaporizados numa entrada quente, e separações ocorrem na fase gasosa. A separação de fase gasosa GC torna ideal para a análise de H2S, como é facilmente libertado a partir da amostra de líquido durante o aquecimento na entrada. Métodos de GC pode ser criado e adaptado para diferentes amostras de acordo com os programas de temperatura utilizadas, colunas implementado, e o uso de cromatografia multidimensional 13-15. Tem havido um grande número de recentes desenvolvimentos para a medição de H2S utilizando GC. Luong et al. Demonstraram H 2 S e outra medição composto de enxofre luz em destilados médios e leves utilizando GC multidimensional e Deans comutação, mas o método não temfoi aplicada a petróleo mais pesado 16. Di Sanzo et ai., Também quantificada H 2 S em gasolina utilizando GC, no entanto, também não tem sido usado em petróleos brutos pesados, e requer arrefecimento 17 sub-ambiente. O método aqui apresentado demonstra um tempo considerável poupança ao longo destes métodos anteriores, com um tempo de análise de completada 5 minutos, em comparação com 10 min (Luong) e 40 min (Di Sanzo). Infelizmente, a aplicação destes métodos em nosso laboratório para comparar a precisão não foi possível devido a restrições de tempo e equipamento. GC Multidimensional permite ao utilizador para explorar a selectividade de duas colunas, em vez de uma única coluna. Em GC convencional, a separação ocorre em uma coluna. No caso de GC multidimensional, a amostra é separado em duas colunas diferentes, aumentando a separação e a selectividade. O interruptor Deans é um dispositivo utilizado para empregar uma configuração de coluna bidimensional. O switch utiliza uma válvula externa de direfluxo de gás ct partir de uma entrada no interruptor para uma das duas portas de saída 18-20. O efluente da primeira coluna pode ser dirigida em qualquer direcção; neste caso, os gases de enxofre de luz são &quot;corte coração&quot; 21 a partir da primeira separação a uma camada porosa tubular aberto em coluna (LOTE) para separação secundária, que tem sido mostrado para ser excelente para a separação de H 2 S provenientes de outros gases com enxofre luz (http://www.chem.agilent.com/cag/cabu/pdf/gaspro.pdf) 22-24. Um detector de quimioluminescência enxofre é utilizado para a detecção, proporcionando selectividade para os compostos de enxofre e eliminar possíveis interferências de quaisquer outros gases leves que pode ter sido transferida para a coluna TRAMA durante o corte do coração. Hidrocarbonetos da amostra de óleo bruto são retidos na primeira coluna de dimensão e são removidas durante um procedimento de retrolavagem; isto protege a coluna PLOT de qualquer contaminação 25-27. Esta abordagem também foi implementado com sucesso para o analysis de inibidores de oxidação em óleos de transformador 28. Aqui, um método GC bidimensional é utilizado para a análise e quantificação dos dissolvido H 2 S em amostras de petróleo bruto pesado. O método é mostrado para ser aplicável sobre um amplo intervalo de concentrações de H 2 S, e também pode ser utilizado para medir H2S em amostras em fase gasosa.

<table><tbody><tr><td>Deans switch</td><td>Agilent</td><td>G2855A</td><td>Or equivalent flow switching device</td></tr><tr><td>Restrictor tubing&amp;nbsp;</td><td>Agilent</td><td>160-2615-10</td><td>Fused silica, deactivated, 180 &amp;micro;m</td></tr><tr><td>HP-PONA column</td><td>Agilent</td><td>19091S-001</td><td></td></tr><tr><td>GasPro column</td><td>Agilent</td><td>113-4332</td><td></td></tr><tr><td>Sulfur chemiluminescence detector, 355</td><td>Agilent/Sievers</td><td>G6603A</td><td></td></tr><tr><td>H&lt;sub&gt;2&lt;/sub&gt;S calibration standard, in He</td><td>Air Liquide</td><td>Custom order</td><td>211 ppm H&lt;sub&gt;2&lt;/sub&gt;S</td></tr><tr><td>CS&lt;sub&gt;2&lt;/sub&gt;</td><td>Fisher Scientific</td><td>C184-500</td><td></td></tr><tr><td>Toluene, HPLC grade</td><td>Fisher Scientific</td><td>T290-4</td><td></td></tr><tr><td>Gas bag, 2 L</td><td>Calibrated Instruments, Inc.</td><td>GSB-P/2</td><td>Twist on/off nozzle</td></tr><tr><td>250 &amp;micro;l gas tight syringe</td><td>Hamilton</td><td>81130</td><td></td></tr><tr><td>500 ml amber glass bottle</td><td>Scientific Specialties</td><td>N73616</td><td></td></tr><tr><td>Open top screw caps</td><td>Scientific Specialties</td><td>169628</td><td></td></tr><tr><td>Tegrabond disc for screw caps</td><td>Chromatographic Specialties</td><td>C889125C</td><td>25 mm, 10/90 MIL</td></tr><tr><td>1 ml gas tight syringe</td><td>Hamilton</td><td>81330</td><td></td></tr><tr><td>2.5% H&lt;sub&gt;2&lt;/sub&gt;S in He gas standard</td><td>Air Liquide</td><td>Custom order</td><td></td></tr></tbody></table>

measurement of h2s in crude oil and crude oil headspace using multidimensional gas chromatography, deans switching and sulfur-selective detection

Um método para a análise do sulfureto de hidrogénio dissolvido em amostras de óleo bruto é demonstrada usando cromatografia em fase gasosa. A fim de eliminar efectivamente a interferências, uma configuração bidimensional coluna é usado, com um interruptor Deans empregue para transferir o sulfureto de hidrogénio a partir da primeira para a segunda coluna (corte de coração). Amostras brutas líquidos são primeiro separados sobre uma coluna de dimetilpolissiloxano, e gases leves e são ainda separados sobre uma coluna de camada porosa ligada tubular aberto (LOTE) que é capaz de separar o sulfureto de hidrogénio a partir de outras espécies de enxofre de luz coração corte. O sulfureto de hidrogénio é então detectada com um detector de quimioluminescência de enxofre, a adição de uma camada adicional de selectividade. A seguir à separação e de detecção de sulfureto de hidrogénio, o sistema é backflushed para remover os hidrocarbonetos de elevado ponto de ebulição presentes nas amostras em bruto e para preservar a integridade cromatográfica. Sulfureto de hidrogénio dissolvido foi quantificado em amostras líquidas a partir de 1.1 para 500 ppm, demonstrando a aplicabilidade larga para uma gama de amostras. O método também tem sido aplicado com sucesso para a análise de amostras de gás a partir do espaço interno de petróleo e gás processo de sacos, com a medição a partir de 0,7 a 9700 ppm de sulfureto de hidrogénio.

De modo a obter a quantificação fiável de H 2 S para as amostras tanto de líquidos e gases, é necessária uma calibração adequada. Para injecções de calibração e as injecções de amostra, o H 2 S de pico não deve ser sobreposto com picos vizinhos e deve ter uma área de pico reprodutíveis. Figura 3 mostra uma injecção de uma amostra do gás, quando o gás é demasiado concentrada para este método. Verificou-se que as concentrações de gás de superior a 500 ppm ut...

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Measurement of H2S in Crude Oil and Crude Oil Headspace Using Multidimensional Gas Chromatography, Deans Switching and Sulfur-selective Detection

A multidimensional gas chromatography method for the analysis of dissolved hydrogen sulfide in liquid crude oil samples is presented. A Deans switch is used to heart-cut light sulfur gases for separation on a secondary column and detection on a sulfur chemiluminescence detector.

Medição de H<sub&gt; 2</sub&gt; S em Crude Oil and Crude Oil Headspace Usando Cromatografia Gasosa Multidimensional, Deans Comutação e Detecção de Enxofre-seletivo

A method for the analysis of dissolved hydrogen sulfide in crude oil samples is demonstrated using gas chromatography. In order to effectively eliminate ...

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Measurement of H2S in Crude Oil and Crude Oil Headspace Using Multidimensional Gas Chromatography, Deans Switching and Sulfur-selective Detection

19.1K visualizações.  Natural Resources Canada. A multidimensional gas chromatography method for the analysis of dissolved hydrogen sulfide in liquid crude oil samples is presented. A Deans switch is used to heart-cut light sulfur gases for separation on a secondary column and detection on a sulfur chemiluminescence detector. 

Vídeo: Measurement of H2S in Crude Oil and Crude Oil Headspace Using Multidimensional Gas Chromatography, Deans Switching and Sulfur-selective Detection

Quantitative Detection of Trace Explosive Vapors by Programmed Temperature Desorption Gas Chromatography-Electron Capture Detector

The direct liquid deposition of solution standards onto sorbent-filled thermal desorption tubes is used for the quantitative analysis of trace explosive vapor samples. The direct liquid deposition method yields a higher fidelity between the analysis of vapor samples and the analysis of solution standards than using separate injection methods for vapors and solutions, i.e., samples collected on vapor collection tubes and standards prepared in solution vials. Additionally, the method can account for instrumentation losses, which makes it ideal for minimizing variability and quantitative trace chemical detection. Gas chromatography with an electron capture detector is an instrumentation configuration sensitive to nitro-energetics, such as TNT and RDX, due to their relatively high electron affinity. However, vapor quantitation of these compounds is difficult without viable vapor standards. Thus, we eliminate the requirement for vapor standards by combining the sensitivity of the instrumentation with a direct liquid deposition protocol to analyze trace explosive vapor samples.

Trace explosive vapors of TNT and RDX collected on sorbent-filled thermal desorption tubes were analyzed using a programmed temperature desorption system coupled to GC with an electron capture detector. The instrumental analysis is combined with direct liquid deposition method to reduce sample variability and account for instrumentation drift and losses.

Detecção quantitativa de rastreamento vapores explosivos por temperatura programada Desorption Gas Chromatography-Electron Captura Detector

The direct liquid deposition of solution standards onto sorbent-filled thermal desorption tubes is used for the quantitative analysis of trace explosive ...

Química

Light-driven Enzymatic Decarboxylation

Oxidoreductases belong to the most-applied industrial enzymes. Nevertheless, they need external electrons whose supply is often costly and challenging. Recycling of the electron donors NADH or NADPH requires the use of additional enzymes and sacrificial substrates. Interestingly, several oxidoreductases accept hydrogen peroxide as electron donor. While being inexpensive, this reagent often reduces the stability of enzymes. A solution to this problem is the in situ generation of the cofactor. The continuous supply of the cofactor at low concentration drives the reaction without impairing enzyme stability. This paper demonstrates a method for the light-catalyzed in situ generation of hydrogen peroxide with the example of the heme-dependent fatty acid decarboxylase OleTJE. The fatty acid decarboxylase OleTJE was discovered due to its unique ability to produce long-chain 1-alkenes from fatty acids, a hitherto unknown enzymatic reaction. 1-alkenes are widely used additives for plasticizers and lubricants. OleTJE has been shown to accept electrons from hydrogen peroxide for the oxidative decarboxylation. While addition of hydrogen peroxide damages the enzyme and results in low yields, in situ generation of the cofactor circumvents this problem. The photobiocatalytic system shows clear advantages regarding enzyme activity and yield, resulting in a simple and efficient system for fatty acid decarboxylation.

We describe a protocol for the light-catalyzed generation of hydrogen peroxide &#8212; a cofactor for oxidative transformations.

Claro conduzido enzimática descarboxilação

Oxidoreductases belong to the most-applied industrial enzymes. Nevertheless, they need external electrons whose supply is often costly and challenging. ...

Chemical Analysis of Water-accommodated Fractions of Crude Oil Spills Using TIMS-FT-ICR MS

Multiple chemical processes control how crude oil is incorporated into seawater and also the chemical reactions that occur overtime. Studying this system requires the careful preparation of the sample in order to accurately replicate the natural formation of the water-accommodated fraction that occurs in nature. Low-energy water-accommodated fractions (LEWAF) are carefully prepared by mixing crude oil and water at a set ratio. Aspirator bottles are then irradiated, and at set time points, the water is sampled and extracted using standard techniques. A second challenge is the representative characterization of the sample, which must take into consideration the chemical changes that occur over time. A targeted analysis of the aromatic fraction of the LEWAF can be performed using an atmospheric-pressure laser ionization source coupled to a custom-built trapped ion mobility spectrometry&#8211;Fourier transform&#8211;ion cyclotron resonance mass spectrometer (TIMS-FT-ICR MS). The TIMS-FT-ICR MS analysis provides high-resolution ion mobility and ultrahigh-resolution MS analysis, which further allow the identification of isomeric components by their collision cross-sections (CCS) and chemical formula. Results show that as the oil-water mixture is exposed to light, there is significant photo-solubilization of the surface oil into the water. Over time, the chemical transformation of the solubilized molecules takes place, with a decrease in the number of identifications of nitrogen- and sulfur-bearing species in favor of those with a greater oxygen content than were typically observed in the base oil.

The low-energy water-accommodated fraction (LEWAF) of crude oil is a challenging system to analyze, because over time, this complex mixture undergoes chemical transformations. This protocol illustrates methods for the preparation of the LEWAF sample and for performing photo-irradiation and chemical analysis by trapped ion mobility spectrometry&#8211;FT-ICR MS.

Análise Química de Frações Acomodadas em Água de Derramamentos de Petróleo Bruto Usando TIMS-FT-ICR MS

Multiple chemical processes control how crude oil is incorporated into seawater and also the chemical reactions that occur overtime. Studying this system ...

Ambiente

Preparation of Authigenic Pyrite from Methane-bearing Sediments for In Situ Sulfur Isotope Analysis Using SIMS

Different sulfur isotope compositions of authigenic pyrite typically result from the sulfate-driven anaerobic oxidation of methane (SO4-AOM) and organiclastic sulfate reduction (OSR) in marine sediments. However, unravelling the complex pyritization sequence is a challenge because of the coexistence of different sequentially formed pyrite phases. This manuscript describes a sample preparation procedure that enables the use of secondary ion mass spectroscopy (SIMS) to obtain in situ &#948;34S values of various pyrite generations. This allows researchers to constrain how SO4-AOM affects pyritization in methane-bearing sediments. SIMS analysis revealed an extreme range in &#948;34S values, spanning from -41.6 to +114.8&#8240;, which is much wider than the range of &#948;34S values obtained by the traditional bulk sulfur isotope analysis of the same samples. Pyrite in the shallow sediment mainly consists of 34S-depleted framboids, suggesting early diagenetic formation by OSR. Deeper in the sediment, more pyrite occurs as overgrowths and euhedral crystals, which display much higher SIMS &#948;34S values than the framboids. Such 34S-enriched pyrite is related to enhanced SO4-AOM at the sulfate-methane transition zone, postdating OSR. High-resolution in situ SIMS sulfur isotope analyses allow for the reconstruction of the pyritization processes, which cannot be resolved by bulk sulfur isotope analysis.

Preparation of Authigenic Pyrite from Methane-bearing Sediments for In Situ Sulfur Isotope Analysis Using SIMS

Analyses of the sulfur isotopic composition (&#948;34S) of pyrite from methane-bearing sediments have typically focused on bulk samples. Here, we applied secondary ion mass spectroscopy to analyze the &#948;34S values of various pyrite generations to understand the diagenetic history of pyritization.

Preparação de pirita Authigenic de sedimentos de metano-rolamento para In Situ enxofre isótopo análise usando o SIMS

Different sulfur isotope compositions of authigenic pyrite typically result from the sulfate-driven anaerobic oxidation of methane (SO4-AOM) and ...

On-line Analysis of Nitrogen Containing Compounds in Complex Hydrocarbon Matrixes

The shift to heavy crude oils and the use of alternative fossil resources such as shale oil are a challenge for the petrochemical industry. The composition of heavy crude oils and shale oils varies substantially depending on the origin of the mixture. In particular they contain an increased amount of nitrogen containing compounds compared to the conventionally used sweet crude oils. As nitrogen compounds have an influence on the operation of thermal processes occurring in coker units and steam crackers, and as some species are considered as environmentally hazardous, a detailed analysis of the reactions involving nitrogen containing compounds under pyrolysis conditions provides valuable information. Therefore a novel method has been developed and validated with a feedstock containing a high nitrogen content, i.e., a shale oil. First, the feed was characterized offline by comprehensive two-dimensional gas chromatography (GC &#215; GC) coupled with a nitrogen chemiluminescence detector (NCD). In a second step the on-line analysis method was developed and tested on a steam cracking pilot plant by feeding pyridine dissolved in heptane. The former being a representative compound for one of the most abundant classes of compounds present in shale oil. The composition of the reactor effluent was determined via an in-house developed automated sampling system followed by immediate injection of the sample on a GC &#215; GC coupled with a time-of-flight mass spectrometer (TOF-MS), flame ionization detector (FID) and NCD. A novel method for quantitative analysis of nitrogen containing compounds using NCD and 2-chloropyridine as an internal standard has been developed and demonstrated.

A method combining comprehensive two-dimensional gas chromatography with nitrogen chemiluminescence detection has been developed and applied to on-line analysis of nitrogen containing compounds in a complex hydrocarbon matrix.

Análise on-line de compostos contendo azoto em matrizes de hidrocarbonetos complexos

The shift to heavy crude oils and the use of alternative fossil resources such as shale oil are a challenge for the petrochemical industry. The ...

Seawater Sampling and Collection

This video documents methods for collecting coastal marine water samples and processing them for various downstream applications including biomass concentration, nucleic acid purification, cell abundance, nutrient and trace gas analyses. For today's demonstration samples were collected from the deck of the HMS John Strickland operating in Saanich Inlet. An A-frame derrick, with a multi-purpose winch and cable system, is used in combination with Niskin or Go-Flo water sampling bottles. Conductivity, Temperature, and Depth (CTD) sensors are also used to sample the underlying water mass. To minimize outgassing, trace gas samples are collected first.  Then, nutrients, water chemistry, and cell counts are determined. Finally, waters are collected for biomass filtration. The set-up and collection time for a single cast is ~1.5 hours at a maximum depth of 215 meters. Therefore, a total of 6 hours is generally needed to complete the collection series described here.

This video documents methods for collecting coastal marine water samples and processing them for various downstream applications including biomass concentration, nucleic acid purification, cell abundance, nutrient and trace gas analyses.

A amostragem da água do mar e Cobrança

This video documents methods for collecting coastal marine water samples and processing them for various downstream applications including biomass ...

Biologia

<meta charset="utf8"></head><body>Uma configuração prática e de baixo custo para medir metano em amostras aquosas

Measuring Dissolved Methane in Aquatic Ecosystems Using An Optical Spectroscopy Gas Analyzer

Measuring greenhouse gas (GHG) fluxes and pools in ecosystems are becoming increasingly common in ecological studies due to their relevance to climate change. With it, the need for analytical platforms adaptable to measuring different pools and fluxes within research groups also grows. This study aims to develop a procedure to use portable optical spectroscopy-based gas analyzers, originally designed and marketed for gas flux measurements, to measure GHG concentrations in aqueous samples. The protocol involves the traditional headspace equilibration technique followed by the injection of a headspace gas subsample into a chamber connected through a closed loop to the inlet and outlet ports of the gas analyzer. The chamber is fabricated from a generic mason jar and simple laboratory supplies, and it is an ideal solution for samples that may require pre-injection dilution. Methane concentrations measured with the chamber are tightly correlated (r2 &#62; 0.98) with concentrations determined separately through gas chromatography-flame ionization detection (GC-FID) on subsamples from the same vials. The procedure is particularly relevant for field studies in remote areas where chromatography equipment and supplies are not readily available, offering a practical, cheaper, and more efficient solution for measuring methane and other dissolved greenhouse gas concentrations in aquatic systems.

<meta charset="utf8"></head><body>Medição de metano dissolvido em ecossistemas aquáticos usando um analisador de gás de espectroscopia óptica

This study demonstrates an approach to measure methane gas concentrations in aqueous samples using portable optical analyzers coupled to an injection chamber in a closed loop. The results are similar to conventional gas chromatography, presenting a practical and low-cost alternative particularly suitable for remote field studies.

Medição de metano dissolvido em ecossistemas aquáticos usando um analisador de gás de espectroscopia óptica

Measuring greenhouse gas (GHG) fluxes and pools in ecosystems are becoming increasingly common in ecological studies due to their relevance to climate ...

Qualitative Characterization of the Aqueous Fraction from Hydrothermal Liquefaction of Algae Using 2D Gas Chromatography with Time-of-flight Mass Spectrometry

Two-dimensional gas chromatography coupled with time-of-flight mass spectrometry is a powerful tool for identifying and quantifying chemical components in complex mixtures. It is often used to analyze gasoline, jet fuel, diesel, bio-diesel and the organic fraction of bio-crude/bio-oil. In most of those analyses, the first dimension of separation is non-polar, followed by a polar separation. The aqueous fractions of bio-crude and other aqueous samples from biofuels production have been examined with similar column combinations. However, sample preparation techniques such as derivatization, solvent extraction, and solid-phase extraction were necessary prior to analysis. In this study, aqueous fractions obtained from the hydrothermal liquefaction of algae were characterized by two-dimensional gas chromatography coupled with time-of-flight mass spectrometry without prior sample preparation techniques using a polar separation in the first dimension followed by a non-polar separation in the second. Two-dimensional plots from this analysis were compared with those obtained from the more traditional column configuration. Results from qualitative characterization of the aqueous fractions of algal bio-crude are discussed in detail. The advantages of using a polar separation followed by a non-polar separation for characterization of organics in aqueous samples by two-dimensional gas chromatography coupled with time-of-flight mass spectrometry are highlighted.

A two-dimensional gas chromatography-time-of-flight mass spectrometry method is described for characterization of the aqueous fraction of bio-crude produced from hydrothermal liquefaction of algae. This protocol can also be employed to analyze the aqueous fraction of liquid products from fast pyrolysis, catalytic fast pyrolysis, catalytic deoxygenation and hydro-treating.

Caracterização qualitativa da fração aquosa de Hydrothermal Liquefação de algas por cromatografia gasosa 2D com Time-of-flight Espectrometria de Massa

Two-dimensional gas chromatography coupled with time-of-flight mass spectrometry is a powerful tool for identifying and quantifying chemical components in ...

Medição de H

Resumo

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