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| Registros recuperados: 24 | |
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| Fabris,Samanta; Freire,Maria Teresa de Alvarenga; Wagner,Roger; Reyes,Felix Guillermo. |
| A simple and low cost method to determine volatile contaminants in post-consumer recycled PET flakes was developed and validated by Headspace Dynamic Concentration and Gas Chromatography-Flame Ionization Detection (HDC-GC-FID). The analytical parameters evaluated by using surrogates include: correlation coefficient, detection limit, quantification limit, accuracy, intra-assay precision, and inter-assay precision. In order to compare the efficiency of the proposed method to recognized automated techniques, post-consumer PET packaging samples collected in Brazil were used. GC-MS was used to confirm the identity of the substances identified in the PET packaging. Some of the identified contaminants were estimated in the post-consumer material at concentrations... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Extraction; Validation; Gas chromatography; PET packaging. |
| Ano: 2010 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0101-20612010000400033 |
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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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| Shiga,Tânia M.; Lajolo,Franco M.; Filisetti,Tullia M.C.C.. |
| The soluble and insoluble cotyledon (SPF-Co and IPF-Co) and tegument (SPF-Te and IPF-Te) cell wall polymer fractions of common beans (Phaseolus vulgaris) were isolated using a chemical-enzymatic method. The sugar composition showed that SPF-Co was constituted of 38.6% arabinose, 23.4% uronic acids, 12.7% galactose, 11.2% xylose, 6.4% mannose and 6.1% glucose, probably derived from slightly branched and weakly bound polymers. The IPF-Co was fractionated with chelating agent (CDTA) and with increasing concentrations of NaOH. The bulk of the cell wall polymers (29.4%) were extracted with 4.0M NaOH and this fraction contained mainly arabinose (55.0%), uronic acid (18.9%), glucose (10.7%), xylose (10.3%) and galactose (3.4%). About 8.7% and 10.6% of the... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Legume; Pectin; Carbohydrate; Gas chromatography. |
| Ano: 2003 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0101-20612003000200007 |
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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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| Rodrigues,Rodney Alexandre Ferreira; Rodrigues,Marili Villa Nova; Oliveira,Thais Isabel Vaccaro; Bueno,Cecilia Zorzi; Oliveira SOUZA,Ilza Maria de; Sartoratto,Adilson; Foglio,Mary Ann. |
| Docosahexaenoic acid is an essential polyunsaturated fatty acid with important metabolic activities. Its conjugated double bonds make it susceptible to decomposition. Its stability may be improved through fatty acid entrapment with a spray-drying technique; however, the many parameters involved in this technique must be considered to avoid affecting the final product quality. Therefore, this study aimed to evaluate the entrapment conditions and yields of fish oil enriched with docosahexaenoic acid ethyl ester. Microcapsules were obtained from Acacia gum using a spray-drying technique. The experimental samples were analyzed by chromatography and delineated by Statistica software, which found the following optimum entrapment conditions: an inlet temperature... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Encapsulated fish oil; Gas chromatography; Response surface; Optimized conditions; Omega-3. |
| Ano: 2011 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0101-20612011000300007 |
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| TURAZZI,Francielle Crocetta; MORÉS,Lucas; MERIB,Josias; CARASEK,Eduardo; NARAIN,Narendra; LIMA,Lucélia Kátia de; NUNES,Maria Lúcia. |
| Abstract This paper describes the application of the solid-phase microextraction (SPME) technique for the determination and monitoring of the volatile profile of minimally-processed pineapple fruit stored at various temperatures (-12 °C, 4 °C and 25 °C) for different periods (1, 4 and 10 days). The SPME fiber coating composed of Car/PDMS presented the best performance. The optimal extraction conditions obtained through a Doehlert design were 60 min at 35 °C. The profiles for the volatile compounds content of the fruit at each stage of storage were determined by gas chromatography-mass spectrometry (GC-MS). The variation in the volatile profile over time was greater when the fruit samples were stored at 25 °C and at -12 °C compared to 4 °C. Thus, according... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Volatile profile; Pineapple; Minimally processed; Microextraction; Gas chromatography. |
| Ano: 2017 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0101-20612017000400663 |
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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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| Zanqui,Ana Beatriz; Maruyama,Swami Arêa; Barilli,Deoclécio José; Ribeiro,Suellen Andressa Oenning; Gomes,Sandra Terezinha Marques; Visentainer,Jesuí Vergílio; Souza,Nilson Evelázio De; Boscolo,Wilson Rogério; Matsushita,Makoto. |
| The objective of this study was to investigate the fatty acid composition of Pimedolus maculatus fillets of fish fed with different diets. The fish were submitted to an adaptation period (over 30 days) and fed only a control diet (diet I). After this period, the fish were divided into two groups: one group received a diet enriched with flaxseed oil (diet II), and the other received a diet enriched with conjugated linoleic acid (CLA) (diet III). Subsequent collections were undertaken after 25 and 50 days. Compared to the control samples, fish fed diet II showed an increase in concentrations of total fatty acid omega-3 (n-3) in the fillets, with an improvement ratio of n-6/n-3. The incorporation of CLA into fish fed diet III was successful. Supplementing the... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Polyunsaturated fatty acids; Gas chromatography; Fatty acids profile. |
| Ano: 2013 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0101-20612013000300023 |
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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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| ANTONIASSI, R.; WILHELM, A. E.; MACHADO, A. F. de F.; GUEDES, A. M. M.; BIZZO, H. R.. |
| A análise da composição em ácidos graxos é realizada, praticamente, para todos os produtos alimentícios, seja por questões nutricionais ou para atender a rotulagem nutricional. Em geral, é uma análise realizada por cromatografia gasosa que requer uma etapa prévia de conversão dos ácidos graxos em ésteres metílicos. Entre os métodos mais utilizados para esta conversão, destaca-se o método de metilação de Hartman e Lago, publicado em 1973. Trata-se do método mais utilizado no Brasil, pela sua simplicidade, rapidez e baixo custo. Neste estudo, foi realizada uma otimização do método original que permitiu aumentar o número de amostras analisadas com redução da quantidade de reagentes e do tempo de análise. As condições de análise foram avaliadas a fim de... |
| Tipo: Folhetos |
Palavras-chave: Fats; Oil; Tecnologia de Alimento; Cromatografia Gasosa; Gordura; Metilação; Óleo; Gas chromatography; Food technology; Methylation. |
| Ano: 2018 |
URL: http://www.infoteca.cnptia.embrapa.br/infoteca/handle/doc/1105249 |
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| Registros recuperados: 24 | |
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