S/G ratio and lignin structure among Eucalyptus hybrids determined by Py-GC/MS and nitrobenzene oxidation

Ohra-aho, Taina; Gomes, Fernando José Borges; Colodette, Jorge Luiz; Tamminen, Tarja

doi:10.1016/j.jaap.2013.01.015

Cited by 82 publications

(64 citation statements)

References 18 publications

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“…Each sample was analyzed at least twice. A more detailed description of the method can be found in Ohra-aho et al (2013). 1 H-13 C heteronuclear single-quantum coherence (HSQC) spectroscopy NMR experiments were carried out at 303 K on a Bruker Avance III 500 MHz instrument (Bruker Biospin GmbH, Rheinstetten, Germany) equipped with a z-gradient double-resonance probe.…”

Section: Methodsmentioning

confidence: 99%

Characterization of dissolved lignins from acetic acid Lignofibre (LGF) organosolv pulping and discussion of its delignification mechanisms

et al. 2014

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Birch chips were cooked by means of the Lignofibre (LGF) organosolv process in acetic acid (AA) and phosphinic acid (H 3 PO 2 ) at 150°C. The delignification rate and structure of the dissolved lignin was followed as a function of time. The degree of delignification increased steadily up to 88% during the 120 min treatment time. The dissolved lignins were precipitated from the spent liquor (SL) by water addition, washed, and purified for the analyses. Elemental analysis, 31 P nuclear magnetic resonance (NMR), heteronuclear single-quantum coherence (HSQC) NMR, pyrolysis-gas chromatography/mass spectrometry (GC/MS), and gel permeation chromatography (GPC) were applied for the structural elucidation. It was found that the cleavage of the β-aryl ether linkages is the main reaction leading to delignification, accompanied by the formation of free phenolic hydroxyl groups and reduction in the content of aliphatic hydroxyl groups. The structure of the dissolved lignin remained the same after the drastic changes at the early stages of cooking (up to 30 min cooking time), indicating that secondary reactions (e.g., condensation) do not take place to a significant extent. H 3 PO 2 probably enhances the acidolysis reaction via an ester derivative that both boosts the cleavage reaction and prevents the formation of the carbocation intermediate that induces condensation. Homolytic cleavage reactions may take place parallel to the acidolytic reactions.

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Section: Methodsmentioning

confidence: 99%

Characterization of dissolved lignins from acetic acid Lignofibre (LGF) organosolv pulping and discussion of its delignification mechanisms

et al. 2014

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“…Analysis of the pyrograms of Eucalyptus hybrids revealed 37 distinct components stemming from H (3), G (17), and S (17) lignin functionalities [63]. Identical side-chain components were measured for both G and S moieties.…”

Section: Pyrolysis Gas Chromatographymentioning

confidence: 99%

“…Although typically employed for the quantitation of lignin monomers (see Section 6.2), pyrolysis gas chromatography/mass spectrometry (pyGCMS) has occasionally been applied to lignin structural analysis [59][60][61][62][63][64][65]. Analysis of the pyrograms of Eucalyptus hybrids revealed 37 distinct components stemming from H (3), G (17), and S (17) lignin functionalities [63].…”

Section: Pyrolysis Gas Chromatographymentioning

confidence: 99%

“…S/G lignin ratios have proven to be important parameters for gauging the recalcitrance of lignin, although no clear trend has been established as to whether or not a high S content results in increased monomeric sugar release following an enzymatic hydrolysis. The traditional methods for measuring lignin monomer composition include NMR, pyGCMS, pyMBMS, and various wet chemical methods such as nitrobenzene oxidation (NBO) and thioacidolysis [4,5,13,56,58,59,[61][62][63][64][65][66]68,70,126,135,157,159,183,240,242,[291][292][293][294][295][296][297][298][299][300][301][302][303][304][305][306][307]. Common pyrolysis and mass spectral fragments are listed in Table 8, and illustrated in Fig.…”

Section: Lignin Monomer Compositionmentioning

confidence: 99%

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Recent innovations in analytical methods for the qualitative and quantitative assessment of lignin

Lupoi

Singh

Parthasarathi

et al. 2015

Renewable and Sustainable Energy Reviews

307

188

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a b s t r a c tAs the attraction of creating biofuels and bio-based chemicals from lignocellulosic biomass has increased, researchers have been challenged with developing a better understanding of lignin structure, quantity and potential uses. Lignin has frequently been considered a waste-product from the deconstruction of plant cell walls, in attempts to isolate polysaccharides that can be hydrolyzed and fermented into fuel or other valuable commodities. In order to develop useful applications for lignin, accurate analytical instrumentation and methodologies are required to qualitatively and quantitatively assess, for example, what the structure of lignin looks like or how much lignin comprises a specific feedstock's cellular composition. During the past decade, various diverse strategies have been employed to elucidate the structure and composition of lignin. These techniques include using two-dimensional nuclear magnetic resonance to resolve overlapping spectral data, measuring biomass with vibrational spectroscopy to enable modeling of lignin content or monomeric ratios, methods to probe and quantify the linkages between lignin and polysaccharides, or refinements of established methods to provide higher throughput analyses, less use of consumables, etc. This review seeks to provide a comprehensive overview of many of the advancements achieved in evaluating key lignin attributes. Emphasis is placed on research endeavored in the last decade.

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“…28 The total ion chromatograms of different samples obtained by Py-GC/MS are shown in Fig. S1; † the identied compounds and corresponding structures are shown in Table 2 and Fig.…”

Section: Py-gc/ms Analysismentioning

confidence: 99%

Acetic acid lignins from Chinese quince fruit (Chaenomeles sinensis): effect of pretreatment on their structural features and antioxidant activities

et al. 2018

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In this study, three pretreatment processes were evaluated for their effects on the structural features and antioxidant activities of lignins extracted by the acetosolv process from the fruit of Chinese quince. The three pretreatments included dephenolization, sugar removal, and multiple processes (a combination of both dephenolization and sugar removal). The results showed that after sugar removal pretreatment, the carbohydrate content, the molecular weight and S/G value of the lignin fractions decreased. However, after dephenolization pretreatment, the carbohydrate content and the molecular weight of the lignin fractions increased. After sugar removal and dephenolization, there were increases in the temperatures corresponding to the maximal rate of decomposition (DTG max ) in all lignin fractions. The radical scavenging index of lignin after sugar removal pretreatment was higher compared to other pretreatments and no treatment. The results of these tests showed that sugar removal, as a pretreatment, enhanced lignin extraction, yielding pure and highly functional lignins. Additionally, dephenolization or multiple process were beneficial to the acquisition of macromolecular lignins. All the results provided references for the biorefinery of biomass rich in polyphenol and sugar compounds.

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S/G ratio and lignin structure among Eucalyptus hybrids determined by Py-GC/MS and nitrobenzene oxidation

Cited by 82 publications

References 18 publications

Characterization of dissolved lignins from acetic acid Lignofibre (LGF) organosolv pulping and discussion of its delignification mechanisms

Characterization of dissolved lignins from acetic acid Lignofibre (LGF) organosolv pulping and discussion of its delignification mechanisms

Recent innovations in analytical methods for the qualitative and quantitative assessment of lignin

Acetic acid lignins from Chinese quince fruit (Chaenomeles sinensis): effect of pretreatment on their structural features and antioxidant activities

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