|
|
|
|
|
| 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 |
| |
|
|
| 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 |
| |
|
| |
|
|
| 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 |
| |
|
|
|
