Discriminative analysis of Eucalyptus camaldulensis grown from seeds of various origins based on lignin components measured by pyrolysis-gas chromatography

Yokoi, Haruhiko; Nakase, Takahito; Ishida, Yasuhiro; Ohtani, Hajime; Tsuge, Shin; Sonoda, Tsutomu; Ona, Toshihiro

doi:10.1016/s0165-2370(00)00137-6

Cited by 43 publications

(36 citation statements)

References 14 publications

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“…However, besides E. globulus, other eucalypt species are also used for papermaking, but their chemical compositions have not been characterized. Only some limited information regarding the composition of lipophilic extractives from E. grandis and E. urograndis wood (Freire et al 2006) and the lignin composition of E. camaldulensis and E. grandis (Ona et al 1997;Gonzá lez-Vila et al 1999;Yokoi et al 1999Yokoi et al , 2001Capanema et al 2005) is available.…”

Section: Introductionmentioning

confidence: 99%

“…Py-GC/MS is a rapid and highly sensitive technique for characterizing the chemical structure of lignin in low amounts of wood (Faix et al 1990;Ralph and Hatfield 1991). Py-GC/MS has already been successfully used for the calculation of lignin S/G ratios in wood, including woods from different eucalypt species (Rodrigues et al 1999;Yokoi et al 1999Yokoi et al , 2001del Río et al 2005).…”

Section: Introductionmentioning

confidence: 99%

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Lipid and lignin composition of woods from different eucalypt species

2007

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The lipid and lignin compositions of woods from the eucalypt species Eucalyptus globulus, E. nitens, E. maidenii, E. grandis, and E. dunnii have been characterized. The lipid composition was analyzed by GC and GC/MS using short-and medium-length high-temperature capillary columns, which allowed the detection of intact highmolecular-weight compounds. Similar lipid compositions were observed in all eucalypt woods, which were dominated by sitosterol, sitosterol esters and sitosteryl 3b-Dglucopyranoside. These substance classes are mainly responsible for pitch deposition during kraft pulping of eucalypt wood. However, some quantitative differences were found in the abundance of different lipid classes, with wood from E. globulus containing the lowest amounts of these pitch-forming compounds. The lignins of all eucalypt woods were analyzed in situ (without previous isolation) by pyrolysis-GC/MS. A predominance of syringyl (S) over guaiacyl (G) lignin units was observed and the S/G ratio was in the range from 2.7 to 4.1. E. globulus wood had the highest S/G ratio, a finding that, together with its low lignin content, explains its easy delignification under kraft cooking conditions.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Lipid and lignin composition of woods from different eucalypt species

2007

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“…The use of this technique in the analysis of herbal products has been very limited (Fang et al, 1990), but its potential is very promising. In a study by Yokoi et al (Yokoi et al, 2001), the authors were able to discriminate samples of Eucaliptus camaldulensis grown from seeds of different origin based on the pyrolysis data using a microfurnace pyrolyser at 450 ºC. The authors identified syringyl and guaiacyl units derived from the lignan in the samples.…”

Section: Discussionmentioning

confidence: 99%

“…Mitsui et al (Mitsui et al, 1995) studied the determination of the total amount of morphine alkaloids in opium by-gas chromatography using principal component analysis. Yokoi (Yokoi et al, 2001) used discriminative analysis of pyrolysis data to classify Eucalyptus camaldulensis samples grown from seeds of various origin based on lignin components measured by pyrolysis-gas chromatography.…”

Section: Introductionmentioning

confidence: 99%

Usefulness of pyrolysis coupled to gas chromatography/mass spectrometry for evaluating the reproducibility of commercial samples of Cymbopogon citratus Stapf., Poaceae

Oliveira¹,

Alvarez²,

Lima³

et al. 2010

Rev. bras. farmacogn.

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RESUMO:"Utilidade da técnica de pirólise acoplada a cromatografia gasosa/espectrometria de massas na avaliação da uniformidade de conteúdo de amostras comerciais de Cymbopogon citratus Stapf". A utilidade da técnica de pirólise acoplada à cromatografia à gás/espectrometria de massas (Py-GC/MS) na avaliação da identidade e reprodutibilidade de diferentes marcas e lotes de amostras comerciais de Cymbopogon citratus Stapf. (comercializado como chá) foi investigada. Amostras do material vegetal foram extraídas com hexano e o extrato foi diretamente pirolisado a 450 ºC utilizando um pirolisador de microforno vertical, interfaciado diretamente com um cromatógrafo à gás/espectrômetro de massas, operado utilizando ionização por impacto eletrônico a 70 eV. As áreas relatives dos picos de interesse identificados nos pirogramas foram utilizadas para análise estatística multivariada, com análise de componentes principais e análise hierárquica de agrupamentos. A análise de components principais dos dados de pirólise foi capaz de representar 84.7% da variabilidade total nos dois primeiros componentes calculados e levou a correta classificação das amostras testadas. O método foi capaz de revelar diferenças importantes entre amostras, quando diferentes lotes da mesma marca foram comparados.Unitermos: Pirólise, Cymbopogon citratus, análise multivariada, análise de componentes principais, análise de agrupamentos. ABSTRACT:The usefulness of pyrolysis coupled to gas chromatography/mass spectrometry (Py-GC/MS) to evaluate the identity and reproducibility of different brands and batches of commercially available samples of Cymbopogon citratus Stapf (sold as tea) was investigated. Samples of the vegetable material were extracted using hexane and the extract was pyrolysed at 450 ºC using a vertical microfurnace pyrolyser interfaced directly with a gas chromatograph/mass spectrometer operated using electron impact ionization at 70 eV. The relative peak areas of the different compounds identified on the pyrograms were used for multivariate data analysis using principal component analysis (PCA) and hierarchical cluster analysis (HCA) techniques. Principal component analysis of pyrolysis data from samples of different brands was able to represent 84.7% of the total variability within the first two principal components, and led to the correct classification of the samples tested. The method was also able to reveal important differences between samples when different batches of the same brand were compared.

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“…Estes compostos foram previamente identificados em madeira de eucaliptos cultivados no Brazil 4-6 e em outros países. 2,22,23 Os compostos foram identificados pela comparação de seus espectros de massa com os da biblioteca Willey 333,000, com dados da literatura [3][4][5][6]8,23 e, quando necessário, por fragmentografia de massas.…”

Section: Caracterização Dos Produtos De Pirólise Das Amostras De Eucaunclassified

Determinação de constituintes químicos em madeira de eucalipto por Pi-CG/EM e calibração multivariada: comparação entre redes neurais artificiais e máquinas de vetor suporte

Nunes¹,

Lima²,

Barbosa³

et al. 2011

Quím. Nova

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Recebido em 25/5/10; aceito em 27/8/10; publicado na web em 30/11/10 DETERMINATION OF CHEMICAL CONSTITUENTS IN EUCALYPTUS WOOD BY Py-GC/MS AND MULTIVARIATE CALIBRATION: COMPARISON BETWEEN ARTIFICIAL NEURAL NETWORK AND SUPPORT VECTOR MACHINES.Multivariate models were developed using Artificial Neural Network (ANN) and Least Square -Support Vector Machines (LS-SVM) for estimating lignin siringyl/guaiacyl ratio and the contents of cellulose, hemicelluloses and lignin in eucalyptus wood by pyrolysis associated to gaseous chromatography and mass spectrometry (Py-GC/MS). The results obtained by two calibration methods were in agreement with those of reference methods. However a comparison indicated that the LS-SVM model presented better predictive capacity for the cellulose and lignin contents, while the ANN model presented was more adequate for estimating the hemicelluloses content and lignin siringyl/guaiacyl ratio.Keywords: analytical pyrolysis; artificial neural network; least square-support vector machine. INTRODUÇÃOAtualmente, a alta demanda de análises dos programas de melhoramento genético voltados à qualidade da madeira de eucalipto tem exigido métodos analíticos mais rápidos e eficientes, uma vez que os métodos padrões requerem procedimentos trabalhosos e demorados, apesar de serem validados e produzirem resultados confiáveis. 1 A pirólise associada à cromatografia gasosa e à espectrometria de massas (Pi-CG/EM) tem se destacado entre as técnicas alternativas utilizadas na caracterização química da madeira de eucalipto, apresentando como principal vantagem o uso de pequenas quantidades de amostra e de procedimentos rápidos com mínimos pré-tratamentos. [2][3][4][5][6] A pirólise analítica pode ser definida como uma técnica de caracterização de determinado material pelas reações de degradação químicas induzidas por energia térmica na ausência de oxigênio, resultando em um conjunto de pequenas espécies moleculares as quais são relacionadas à composição da amostra original. 7 A possibilidade da cromatografia gasosa de separar os produtos provenientes da piró-lise e da espectrometria de massas de identificá-los faz da associação entre estas técnicas uma poderosa ferramenta para caracterização de diversos materiais poliméricos não voláteis.Embora os pirogramas (cromatogramas referentes às amostras pirolisadas) da madeira de eucalipto contenham informações sobre a composição química das amostras, o seu uso em modelos convencionais de calibração univariada para a estimativa de parâmetros composicionais, como os teores de celulose ou de lignina, pode ser dificultado devido a esse tipo de informação estar distribuída por todo o pirograma. 2,4-6,8 Entretanto, modelos de calibração para sistemas com resposta multivariada, como os pirogramas, podem ser construídos empregando métodos de calibração multivariada.Entre os métodos de calibração multivariada têm se destacado as redes neurais artificiais 9 e, mais recentemente, as máquinas de vetor suporte por mínimos quadrados. 10 As redes neurais artificiais (ANN, Artificial N...

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Discriminative analysis of Eucalyptus camaldulensis grown from seeds of various origins based on lignin components measured by pyrolysis-gas chromatography

Cited by 43 publications

References 14 publications

Lipid and lignin composition of woods from different eucalypt species

Lipid and lignin composition of woods from different eucalypt species

Usefulness of pyrolysis coupled to gas chromatography/mass spectrometry for evaluating the reproducibility of commercial samples of Cymbopogon citratus Stapf., Poaceae

Determinação de constituintes químicos em madeira de eucalipto por Pi-CG/EM e calibração multivariada: comparação entre redes neurais artificiais e máquinas de vetor suporte

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