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| Registros recuperados: 16 | |
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| Espinosa, Luisa F.; Ramírez, Gustavo; Campos, Néstor H.. |
| En los sedimentos superficiales aledaños al manglar, de cuatro estaciones dentro de la Ciénaga Grande de Santa Marta y una estación en la Bahía de Chengue, se analizaron las concentraciones de seis residuos de plaguicidas organoclorados (lindano, heptacloro, aldrin, pp'DDE, pp'DDD y pp'DDT), mediante la técnica de cromatografía gas-líquido. Se realizaron muestreos trimestrales entre marzo y diciembre de 1993, tratando de abarcar las principales épocas climáticas de la región (seca, lluviosa menor, seca menor y lluviosa mayor). Mediante análisis de varianza multifactorial se encontraron diferencias significativas solamente en las concentraciones de lindano, heptacloro y pp'DDE, entre las diferentes épocas climática; los otros tres compuestos (aldrin, pp'DDD... |
| Tipo: Journal Contribution |
Palavras-chave: Ecology; Chemical analysis; Salinity effects; Gas chromatography; Organic matter; Coastal lagoons; Estuaries; Mangroves; Ecology; Organic matter; Estuaries; Gas chromatography; Coastal lagoons; Mangroves; Http://aims.fao.org/aos/agrovoc/c_2467; Http://aims.fao.org/aos/agrovoc/c_5387; Http://aims.fao.org/aos/agrovoc/c_2673; Http://aims.fao.org/aos/agrovoc/c_11097; Http://aims.fao.org/aos/agrovoc/c_1697; Http://aims.fao.org/aos/agrovoc/c_16190. |
| Ano: 1999 |
URL: http://hdl.handle.net/1834/3804 |
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| Canesin,Edmilson Antonio; de Oliveira,Cláudio Celestino; Matsushita,Makoto; Felicidade Dias,Lucia; Reghiany Pedrão,Mayka; Evelazio de Souza,Nilson. |
| Background: Residual oils were characterized according to their physicochemical properties, i.e. acidity, iodine value, peroxide value and saponification number, to evaluate the degradation level and viability for biodiesel production. Results: The methyl esters of fatty acids (FAME) from samples of residual bovine, chicken and soybean oils were quantified by using four transesterification methods, using acidic and basic catalysis and, gas chromatography with flame ionization detector (GC-FID). Methods that used acidic catalysis at a lower temperature were the most efficient. Methyl biodiesel samples were synthesized by basic catalysis (KOH) for all quantified oils and the physicochemical properties of the biofuel were evaluated, i.e. viscosity, flash and... |
| Tipo: Journal article |
Palavras-chave: Biodiesel properties; Gas chromatography; Infrared; Transesterification methods. |
| Ano: 2014 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-34582014000100007 |
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| Dubois, Nolwenn; Barthomeuf, Chantal; Berge, Jean-pascal. |
| It is essential to have simple rapid methods for the determination of fatty acid structures. Traditionally, fatty acids are analysed by gas chromatography using their methyl ester derivatives (FAME). However, their corresponding mass spectra exhibit molecular ions but are usually devoid of ions indicative of structural features and, notably, the position of double bounds on the aliphatic chains [1]. In the most useful approach to structure determination, the carboxyl group is derivatised with a reagent containing a nitrogen atom. Recently, a convenient method for preparing picolinyl esters from intact lipids has been published [2]. However, some problems occurred in our laboratory when this method was used, leading to some modifications and optimisation.... |
| Tipo: Text |
Palavras-chave: Sensitivity; Sterol esters; Fatty acid methyl esters; Gas chromatography; Mass spectrometry; Picolinyl esters. |
| Ano: 2006 |
URL: http://archimer.ifremer.fr/doc/2006/publication-2125.pdf |
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| Teló, Gustavo Mack; Marchesan, Enio; Zanella, Renato; Peixoto, Sandra Cadore; Prestes, Osmar Damian; Oliveira, Maurício Limberger. |
| The objective of this study was to analyse residues of fungicides and insecticides in rice grains that were subjected to different forms of processing. Field work was conducted during three crop seasons, and fungicides and insecticides were applied at different crop growth stages on the aerial portion of the rice plants. Azoxystrobin, difenoconazole, propiconazole, tebuconazole, and trifloxystrobin fungicides were sprayed only once at the R2 growth stage or twice at the R2 and R4 growth stages; cypermethrin, lambda-cyhalothrin, permethrin, and thiamethoxam insecticides were sprayed at the R2 growth stage; and permethrin was sprayed at 5-day intervals from the R4 growth stage up to one day prior to harvest. Pesticide residues were analysed in uncooked,... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: 5.01.03.01.-6 Oryza sativa L.; Food; Gas chromatography; Pesticides; Grains quality Manejo e Tratos Culturais. |
| Ano: 2017 |
URL: http://periodicos.uem.br/ojs/index.php/ActaSciAgron/article/view/30594 |
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| Bertagnolli,Silvana Maria Michelin; Bernardi,Gabrieli; Donadel,Jossiê Zamperetti; Fogaça,Aline de Oliveira; Wagner,Roger; Penna,Neidi Garcia. |
| ABSTRACT: Although different tropical fruit species have been used in the development of fermented beverages, there are only few references in the literature to the production of natural sparkling wines from fruits other than grapes. In this sense, the objective of the present research was the development and physicochemical and volatile characterization of a natural sparkling guava wine produced by the champenoise method. Volatile compounds were identified by gas chromatography coupled to mass spectrometry using the headspace solid-phase microextraction (HS-SPME) technique on samples. Eighty-nine volatile compounds were detected, of which 51 were identified. Esters were the predominant class of volatile compounds (a total of 26), followed by alcohols... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Fermentation; Psidium guajava L.; Volatile compounds; Gas chromatography. |
| Ano: 2017 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-84782017000900782 |
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| Nobre, Danubia Aparecida Costa; Silva, Rodrigo Rocha; Guimarães Nasser, Vinicius; Silva, Geraldo Humberto; Aquino, Leonardo Angelo; Macedo, Willian. |
| Poucos estudos apresentam interações entre a fisiologia das plantas e sua posterior composição química, quando cultivadas em diferentes arranjos. Esta pesquisa buscou compreender a relação entre o espaço de cultivo da soja e sua influência sobre a qualidade da semente. Foram estudadas duas cultivares de soja (Tec 7849 Ipro e Monsoy 6972 Ipro) em quatro arranjos espaciais distintos (50,0 x 7,1; 40,0 x 8,9; 30,0 x 11,9 e 18,9 x 18,9 ou 16,2 x 16,2 cm, respectivamente). Durante os estádios fenológicos V4 e R2, foram analisadas trocas gasosas e na colheita, foram constituídos 2 grupos, um de sementes frescas e outro de sementes envelhecidas, para ambos os grupos se analisaram: teste de germinação, vigor, índice de velocidade de germinação, massa fresca das... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Gas exchange; Germination; Lipids; Gas chromatography; Trocas gasosas; Germinação; Lipídeos; Cromatografia gasosa. |
| Ano: 2023 |
URL: http://periodicosonline.uems.br/index.php/agrineo/article/view/6850 |
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| Jaramillo-Colorado, Beatriz Eugenia; Suarez-López , Samyr; Marrugo-Santander, Vanessa. |
| The objectives of this work were the study of the volatile chemical composition of essential oils (EO’s) from Bursera graveolens obtained in the locality of Malagana, municipality of Mahates, Bolívar, Colombia, as well as to evaluate their repellent and fumigant properties. EO’s were extracted by hydro-distillation and characterized by gas chromatography-mass spectrometry (GC-MS). The major compounds found in B. graveolens were limonene (42.2%), pulegone (20.9%), carvone (7.5%), caryophyllene (4.1%), and trans-carveol (3.8%). The repellent activity of EO’s was determined by the area preference method, where the EO of B. graveolens presented repellent activity against the Tribolium castaneum weevil at a concentration of 1 at 2% and 4 hours of exposure (88.1... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Gas chromatography; Bioactivity; Essential oils; Bursera graveolens; Tribolium castaneum; Terpenes.. |
| Ano: 2019 |
URL: http://periodicos.uem.br/ojs/index.php/ActaSciBiolSci/article/view/46822 |
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| Registros recuperados: 16 | |
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