Consulta: subjectFacets:"Gas chromatography"
Registros recuperados: 16
Data/hora: 05/06/2024 04:42:27

PLANT PHYSIOLOGICAL PERFORMANCE AND SEED CHEMICAL COMPOSITION OF SOYBEAN UNDER DIFFERENT SPATIAL ARRANGEMENT
Provedor de dados: 196
Autores: 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

A real-time PCR genotyping assay to detect FAD2A SNPs in peanuts (Arachis hypogaea L.)
Provedor de dados: 69
Autores: Barkley,Noelle A; Wang,Ming Li; Pittman,Roy N.
The high oleic (C18:1) phenotype in peanuts has been previously demonstrated to result from a homozygous recessive genotype (ol1ol1ol2ol2) in two homeologous fatty acid desaturase genes (FAD2A and FAD2B) with two key SNPs. These mutant SNPs, specifically G448A in FAD2A and 442insA in FAD2B, significantly limit the normal function of the desaturase enzyme activity which converts oleic acid into linoleic acid by the addition of a second double bond in the hydrocarbon chain. Previously, a genotyping assay was developed to detect wild type and mutant alleles in FAD2B. A real-time PCR assay has now been developed to detect wild type and mutant alleles (G448A) in FAD2A using either seed or leaf tissue. This assay was demonstrated to be applicable for the...
Tipo: Journal article
Palavras-chave: Fatty acid composition; Gas chromatography; Peanut (Arachis hypogaea L.); Real-time PCR; SNP genotyping.
Ano: 2011
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-34582011000100009

Characterization of residual oils for biodiesel production
Provedor de dados: 69
Autores: 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

Automação de planilhas eletrônicas para o cálculo de índices de retenção na análise de óleos essenciais.
Provedor de dados: 14
Autores: GAMA, P. E.; BARBOZA, E. G.; SANTOS, M. C. da S.; BIZZO, H. R.
Na publicação é descrita a elaboração de uma planilha para a automação do cálculo dos índices de retenção empregados na identificação dos constituintes químicos de óleos essenciais. A planilha é constituída de um grupo de funções matemáticas pré-existentes na plataforma Microsoft Excel, estruturadas e combinadas de modo a automatizar o processo de interpolação dos dados de tempos de retenção necessários ao cálculo. O emprego da planilha resultou em redução no tempo gasto pelos profissionais envolvidos na análise, bem como na redução do retrabalho decorrente de erros de digitação, melhorando a eficiência e a qualidade dos resultados analíticos obtidos pelo laboratório.
Tipo: Comunicado Técnico (INFOTECA-E)
Palavras-chave: Kovats; Otimização.; Cromatografia Gasosa; Tecnologia de Alimento.; Chromatography; Gas chromatography.
Ano: 2017
URL: http://www.infoteca.cnptia.embrapa.br/infoteca/handle/doc/1081899

Accumulation and depuration of hydrocarbons in the mangrove oyster Crassostrea rhizophorae
Provedor de dados: 5
Autores: Delcastillo, C; Corredor, J; Morell, J.
Adult specimens of Crassostrea rhizophorae were exposed to diesel oil dispersed in seawater. The experiment consisted of a 10 days contamination period and 15 days depuration period. Oyster samples were extracted, and analysed by gas chromatography and UV fluorescence spectroscopy. The concentrations of n-alkanes, branched alkanes, unresolved complex mixture (UCM) and aromatic hydrocarbons were determined. The oysters accumulated the hydrocarbons rapidly, reaching a maximum concentration of 387.5 ug/g (wet weight). After exposure to uncontaminated seawater, the oysters were able to reduce their hydrocarbon load to 5.6 ug/g. The data indicates that C. rhizophorae is capable of preferential accumulation and depuration of hydrocarbons. Apparently, the oysters...
Tipo: Text
Palavras-chave: Crassostrea rhizophorae; Bivalvia; Fluorescence spectroscopy; Gas chromatography; Oyster culture; Hydrocarbons; Marine pollution; Accumulation; Self purification.
Ano: 1992
URL: http://archimer.ifremer.fr/doc/1992/acte-1602.pdf

Convenient preparation of picolinyl derivatives from fatty acid esters
Provedor de dados: 5
Autores: 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

Análisis de residuos de organoclorados en los sedimentos de zonas de manglar en la Ciénaga Grande de Santa Marta y la Bahía de Chengue, Caribe colombiano
Provedor de dados: 20
Autores: 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

Molecular and morphological characterization of hydrochar produced by microwave-assisted hydrothermal carbonization of cellulose
Provedor de dados: 86
Autores: Guiotoku,Marcela; Hansel,Fabricio Augusto; Novotny,Etelvino Henrique; Maia,Claudia Maria Branco de Freitas.
The objective of this work was to characterize the morphology and molecular composition of the hydrochar produced by microwave-assisted hydrothermal carbonization of cellulose. The produced hydrochar consists mainly of aggregate microspheres with about 2.0 µm in diameter, with aliphatic and aromatic structures and the presence of carbonyl functional groups. The aromatic groups are formed mainly by benzofuran-like structures, being chemically different from common cellulose char. Microwave-assisted hydrothermal carbonization yields a functionalized carbon-rich material similar to that produced by the conventional hydrothermal process.
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Anthropogenic dark earth of Amazonia; Biochar; Charcoal; Gas chromatography; Mass spectrometry; Nuclear magnetic resonance.
Ano: 2012
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-204X2012000500008

Fenitrothion and esfenvalerate stability during corn and wheat sample processing
Provedor de dados: 63
Autores: Vásquez-Castro,Javier Alberto; Baptista,Gilberto Casadei de; Trevizan,Luiz Roberto Pimentel; Gadanha Junior,Casimiro Dias.
The presence of insecticide residues in cereals represents a risk for the consumer, because these substances are used in large scale to protect stored grains from the attack of pests. The effects of three processing methods for corn and wheat samples on the stability of stored-grain protective insecticides were here evaluated. Fenitrothion and esfenvalerate were applied so as to produce theoretical concentrations of 10 and 0.5 mg kg-1, respectively. Two hours after treatment, the grains were processed and deposition was analyzed by gas chromatography. Grain species did not influence insecticide stability. This stability was only dependent upon the processing method and insecticide type. Grains processed together with dry ice provided the greatest...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Stored grain; Insecticide degradation; Dry ice; Gas chromatography.
Ano: 2008
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162008000200008

A system to evaluate the performance of hydraulic nozzles used in stored grain preotection trials
Provedor de dados: 63
Autores: Vásquez-Castro,Javier A.; Baptista,Gilberto C. de; Gadanha Jr.,Casimiro D.; Trevizan,Luiz R.P.
We developed a system to evaluate the performance of hydraulic nozzles used in stored corn and wheat grain protection experiments. An insecticidal mix was used as test fluid to determine the transversal volumetric distribution and droplets spectrum of a model TJ-60 8002EVS hydraulic nozzle. A mobile application system was built to apply a rate equivalent to 5 L t-1 and obtain theoretical concentrations of 10 and 0.5 mg kg-1 of fenitrothion and esfenvalerate, respectively. The corn and wheat grains were spread out as a fine layer. Three glass slides (0.1 × 0.05 m) were placed on the top surface of the grains to ensure that the intended application rate was achieved. After treatment, the deposits on both matrices were analyzed by gas chromatography. The...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Application technology; Gas chromatography; Insecticide deposits; Corn; Wheat.
Ano: 2007
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162007000600001

Chemometric identification and nutritional evaluation of three species of Lutjanidae (Perciformes) from the Amazonian Atlantic Coast based on fatty acid profiles
Provedor de dados: 36
Autores: ALMEIDA,Edilene Santos de; SILVA,Evaldo Martins da.
ABSTRACT The fatty acid (FA) profiles of fish species with a similar genetic or geographic origin are important quality parameters that attract bioecological interest because they are inﬂuenced by the nutritional habits of the species. The aim of this study was to determine the proximate compositions and FA profiles of heart, brain and muscle tissues from three fish species (Lutjanus purpureus, Lutjanus synagris and Ocyurus chrysurus) captured from the Amazonian Atlantic Coast. In addition to performing nutritional analysis of the FA profiles, principal components analysis (PCA) was performed as a chemometric tool to discriminate among the species. Lutjanus synagris had the highest protein content (18.23%), while O. chrysurus possessed the highest lipid...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Multivariate analysis; Gas chromatography; Lutjanus purpureus; Lutjanus synagris; Ocyurus chrysurus.
Ano: 2016
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0044-59672016000400401

Physiological quality and seed respiration of primed Jatropha curcas seeds
Provedor de dados: 39
Autores: Horbach,Micheli Angelica; Dranski,João Alexandre Lopes; Malavasi,Ubirajara Contro; Malavasi,Marlene de Matos.
ABSTRACT Seed deterioration is a natural and irreversible process. Nevertheless, seed priming with water and antioxidants can minimize oxidative damage in oilseeds, resulting in attenuation of seed deterioration. The objective of this assay was to evaluate seed priming on respiratory activity of Jatropha curcas submitted to accelerated aging. Seeds from two provenances (Janauba and Pedro J. Caballero) were submitted to three priming treatments (control, immersion in deionized water, and with 750 µmol L-1 of ascorbic acid) and treated for accelerated aging at 41 °C for 72 h. The results showed that the priming of J. curcas seeds promoted tolerance to accelerated aging. Primed seeds, with ascorbic acid from Janauba and deionized water from Pedro J....
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Accelerated aging; Ascorbic acid; Gas chromatography; Oil seeds; Physic nut.
Ano: 2018
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0102-33062018000100063

Fungicide and insecticide residues in rice grains
Provedor de dados: 1
Autores: 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

Volatile chemical composition of essential oil from Bursera graveolens (Kunth) Triana &amp; Planch and their fumigant and repellent activities
Provedor de dados: 3
Autores: 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

Comparison of the quantification of caffeine in human plasma by gas chromatography and ELISA
Provedor de dados: 56
Autores: Carregaro,A.B.; Woods,W.E.; Tobin,T.; Queiroz-Neto,A.
In the present study we evaluated the precision of the ELISA method to quantify caffeine in human plasma and compared the results with those obtained by gas chromatography. A total of 58 samples were analyzed by gas chromatography using a nitrogen-phosphorus detector and routine techniques. For the ELISA test, the samples were diluted to obtain a concentration corresponding to 50% of the absorbance of the standard curve. To determine whether the proximity between the I50 of the standard curve and that of the sample would bring about a more precise result, the samples were divided into three blocks according to the criterion of difference, in modulus, of the I50 of the standard curve and of the I50 of the sample. The samples were classified into three...
Tipo: Info:eu-repo/semantics/other
Palavras-chave: Gas chromatography; ELISA; Caffeine; Plasma; Quantification.
Ano: 2001
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2001000600019

Natural sparkling guava wine: volatile and physicochemical characterization
Provedor de dados: 65
Autores: 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