Analytical Pyrolysis
Mostrando 13-21 de 21 artigos, teses e dissertações.
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13. Uso da pirólise acoplada à cromatografia gasosa e à espectrometria de massas na determinação da relação siringil/guaiacil em ligninas de clones de Eucalyptus spp / Use of the pyrolysis coupled with gas chromatography and mass spectrometry in the determination of the syringyl/guaiacyl ratio in Eucalyptus spp. clones lignins
A relação siringil/guaiacil (S/G) foi determinada em madeiras de seis diferentes clones de Eucalyptus cultivados em quatro regiões do estado brasileiro de Minas Gerais. As determinações foram realizadas por pirólise acoplada à cromatografia gasosa e à espectrometria de massas (Pi- CG/EM) e os resultados obtidos foram comparados à valores de referên
Publicado em: 2008
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14. Desenvolvimento de métodos para determinações elementares em cimentos por espectrometria de absorção atômica com forno de grafite e amostragem direta de sólidos / Development of methods for elemental determination in cements by atomic absorption spectrometry with graphite furnace and direct solid sampling
The objective of this work was the development of analytical methods for the determination of Cd, Pb, Cu, Ni, Co, Cr e Mn in Portland cement by solid sampling graphite furnace atomic absorption spectrometry. It was not necessary any pretreatment of the samples, because the particles size (12 µm) were apropriated for direct solid analysis. The heating pr
Publicado em: 2008
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15. DETERMINATION OF SN IN HUMAN MILK BY GRAPHITE FURNACE ATOMIC ABSORPTION SPECTROMETRY / DETERMINAÇÃO DE SN EM LEITE HUMANO POR ESPECTROMETRIA DE ABSORÇÃO ATÔMICA NO FORNO DE GRAFITE
Tin is a metal of natural occurrence which is mainly extracted from the mineral cassiterite, SnO2. Tin may be released to the atmosphere from both natural and anthropogenic sources. In nature, it occurs in both inorganic and organic forms, and the shorter the organic chain associated to the metal, the higher the toxicity of the compound. Organotin compounds
Publicado em: 2008
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16. Caracterização dos produtos líquidos e do carvão da pirólise de serragem de eucalipto
This study proposes the low temperature pyrolysis as an alternative conversion process for residual biomass and for obtaining gaseous, liquid and solid chemical feedstocks. Using a bench electrical pyrolysis oven, four product fractions from eucalyptus sawdust were obtained: a gaseous one, two liquid (aqueous and oily), and a solid residue (char). These prod
Química Nova. Publicado em: 2007-08
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17. Simultaneous determination of As, Co and Se in gasoline, petroleum and lubricating oil by graphite furnace atomic absorption spectrometry / Explorando a espectrometria de absorção atômica com atomização eletrotérmica para a determinação simultânea de As, Co e Se em produtos petrolíferos
In this work analytical methods were developed for simultaneous determination of As, Co and Se in gasoline, petroleum and lubricating oil by graphite furnace atomic absorption spectrometry. Strategies for the sample preparation were based on the emulsion for gasoline and petroleum and acid digestion using microwave oven for lubricating oil. The heating progr
Publicado em: 2006
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18. "Comparative evaluation of procedures for agroindustrials sample preparation in the determination of inorganic elements by spctrometric techniques" / "Avaliação comparativa de procedimentos para o preparo de amostras agroindustriais na determinação de elementos inorgânicos por técnicas espectrométricas"
Analytical comparative procedures for the preparation of three types of agro industrials samples (rocks, coffees and antibiotics) were evaluated in the determination of inorganic elements by flame atomic absorption spectrometry (FAAS), flame atomic emission spectrometry (FAES) and graphite furnace atomic absorption spectrometry (GFAAS) techniques. Six decomp
Publicado em: 2006
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19. Estudo da utilização de padrão interno em determinações multielementares por espectrometria de absorção atômica com atomização eletrotérmica e detecção simultânea / Study of the use of internal standard for multielement determinations by electrothermal atomic absorption spectrometry with simultaneous detection
A systematic study involving the use of internal standard for multielement determinations by electrothermal atomic absorption spectrometry was developed. The main objective of this work was evaluate the possibility of improving precision and accuracy of the analytical results for biological fluids. The sample pre-treatment was reduced to a single dilution st
Publicado em: 2004
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20. Mass spectrometric monitoring of solid phase phosphate triester synthesis of DNA fragments.
A new and convenient pyrolysis mass spectrometric approach for monitoring solid phase phosphate triester synthesis of oligodeoxyribonucleotides in 5'-3' direction has been developed. The base-typical fragment ions produced by pyrolysis at 280 degrees C of the polymer-bound oligonucleotide triesters in the mass spectrometer permit the analytical monitoring of
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21. Preferential degradation of phenolic lignin units by two white rot fungi.
The differential biodegradation of phenolic and nonphenolic (C-4-etherified) lignin units in wheat straw treated with the white rot fungi Pleurotus eryngii and Phanerochaete chrysosporium was investigated under solid-state fermentation conditions. Two analytical techniques applied to permethylated straw were used for this purpose, i.e., alkaline CuO degradat