Consulta: subjectFacets:"Sample preparation"
Registros recuperados: 4
Data/hora: 11/06/2024 10:52:45

Separomics applied to the proteomics and peptidomics of low-abundance proteins: choice of methods and challenges - a review
Provedor de dados: 74
Autores: Baracat-Pereira,Maria Cristina; Barbosa,Meire de Oliveira; Magalhães Júnior,Marcos Jorge; Carrijo,Lanna Clicia; Games,Patrícia Dias; Almeida,Hebréia Oliveira; Sena Netto,José Fabiano; Pereira,Matheus Rodrigues; Barros,Everaldo Gonçalves de.
The enrichment and isolation of proteins are considered limiting steps in proteomic studies. Identification of proteins whose expression is transient, those that are of low-abundance, and of natural peptides not described in databases, is still a great challenge. Plant extracts are in general complex, and contaminants interfere with the identification of proteins involved in important physiological processes, such as plant defense against pathogens. This review discusses the challenges and strategies of separomics applied to the identification of low-abundance proteins and peptides in plants, especially in plants challenged by pathogens. Separomics is described as a group of methodological strategies for the separation of protein molecules for proteomics....
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Sample preparation; Complex protein extract; Subproteomes; Low-abundance proteins; Cell wall proteins.
Ano: 2012
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572012000200009

Characterisation of dissolved organic compounds in hydrothermal fluids by stir bar sorptive extraction - gas chomatography - mass spectrometry. Case study: the Rainbow field (36 degrees N, Mid-Atlantic Ridge)
Provedor de dados: 5
Autores: Konn, Cecile; Charlou, Jean-luc; Donval, Jean-pierre; Holm, Nils G.
The analysis of the dissolved organic fraction of hydrothermal fluids has been considered a real challenge due to sampling difficulties, complexity of the matrix, numerous interferences and the assumed ppb concentration levels. The present study shows, in a qualitative approach, that Stir Bar Sorptive Extraction (SBSE) followed by Thermal Desorption - Gas Chromatography - Mass Spectrometry (TD-GC-MS) is suitable for extraction of small sample volumes and detection of a wide range of volatile and semivolatile organic compounds dissolved in hydrothermal fluids. In a case study, the technique was successfully applied to fluids from the Rainbow ultramafic-hosted hydrothermal field located at 36 degrees 14'N on the Mid-Atlantic Ridge (MAR). We show that...
Tipo: Text
Palavras-chave: Sample preparation; Extraction; Organic compounds; Hydrothermal fluids; Ultramafic rocks.
Ano: 2012
URL: http://archimer.ifremer.fr/doc/00114/22514/20196.pdf

Isotope determination of sulfur by mass spectrometry in soil samples
Provedor de dados: 90
Autores: Rossete,Alexssandra Luiza Rodrigues Molina; Carneiro,Josiane Meire Toloti; Sant Ana Filho,Carlos Roberto; Bendassolli,José Albertino.
Sulphur plays an essential role in plants and is one of the main nutrients in several metabolic processes. It has four stable isotopes (32S, 33S, 34S, and 36S) with a natural abundance of 95.00, 0.76, 4.22, and 0.014 in atom %, respectively. A method for isotopic determination of S by isotope-ratio mass spectrometry (IRMS) in soil samples is proposed. The procedure involves the oxidation of organic S to sulphate (S-SO4(2-)), which was determined by dry combustion with alkaline oxidizing agents. The total S-SO4(2-) concentration was determined by turbidimetry and the results showed that the conversion process was adequate. To produce gaseous SO2 gas, BaSO4 was thermally decomposed in a vacuum system at 900 ºC in the presence of NaPO3. The isotope...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Sample preparation; Soil samples; Isotopic dilution; Labeled material; Stable isotope; 34S.
Ano: 2012
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832012000600012

Organic sulfur oxidation to sulfate in soil samples for total sulfur determination by turbidimetry
Provedor de dados: 90
Autores: Rossete,Alexssandra Luiza Rodrigues Molina; Bendassolli,José Albertino; Trivelin,Paulo Cesar Ocheuze.
Sulfur in the soil occurs in two basic forms, organic and inorganic S. The organic form accounts for 95 % of S in most soils. The effectiveness of organic S to oxidate to sulfate was evaluated for total S determination in soil samples by wet (acid) and dry-ash (alkaline) oxidation methods. To evaluate the wet method and the possible use as a reference when evaluating the dry method proposed here, a reference standard from the US National Institute of Standards and Technology (NIST) was used (Montana Soil - NIST 2710). The dry-ash oxidation process with alkaline oxidizing agents is one of the simplest oxidation methods of organic S to the sulfate form and was compared with the wet process. The objective of the study was to develop a dry method that would be...
Tipo: Info:eu-repo/semantics/report
Palavras-chave: Sample preparation; Turbidimetric method; Spectrophotometry.
Ano: 2008
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832008000600031