Characterization of Kraft Lignin Prepared from Mixed Hardwoods by 2D HMQC and 31P NMR Analyses
This study was conducted to determine the lignin substructures, hydroxyl (phenolic + aliphatic) contents, and carboxyl contents in kraft lignin (KL) prepared from mixed hardwoods by using 2D Heteronuclear Multiple Quantum Coherence Nuclear Magnetic Resonance (HMQC NMR) and 31P NMR techniques. Based...
| Main Authors: | , , |
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| Format: | Article |
| Language: | English |
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North Carolina State University
2022-11-01
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| Series: | BioResources |
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| Online Access: | https://ojs.cnr.ncsu.edu/index.php/BRJ/article/view/22110 |
| _version_ | 1797794844077195264 |
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| author | Ji Sun Mun Justin Alfred Pe III Sung Phil Mun |
| author_facet | Ji Sun Mun Justin Alfred Pe III Sung Phil Mun |
| author_sort | Ji Sun Mun |
| collection | DOAJ |
| description | This study was conducted to determine the lignin substructures, hydroxyl (phenolic + aliphatic) contents, and carboxyl contents in kraft lignin (KL) prepared from mixed hardwoods by using 2D Heteronuclear Multiple Quantum Coherence Nuclear Magnetic Resonance (HMQC NMR) and 31P NMR techniques. Based on 2D HMQC NMR analysis of KL, stilbene and vanillin substructures were present in the aromatic region, while trace amounts of β-O-4 and β-β moieties were detected in the oxygenated aliphatic region. The total hydroxyl content calculated from 31P NMR was 5.24 mmol/g KL. The aliphatic hydroxyl content was 1.04 mmol/g KL, and phenolic hydroxyl content was 4.20 mmol/g KL. Of the phenolic hydroxyl groups, the contribution of syringyl (S) and guaiacyl (G) was 1.02 and 0.97 mmol/g KL, respectively. The S/G molar ratio of KL calculated from 31P NMR was 1.05. The carboxyl content was 0.44 mmol/g KL. |
| first_indexed | 2024-03-13T03:08:55Z |
| format | Article |
| id | doaj.art-814c245cecee43a2b3fc291e9a3a77c9 |
| institution | Directory Open Access Journal |
| issn | 1930-2126 |
| language | English |
| last_indexed | 2024-03-13T03:08:55Z |
| publishDate | 2022-11-01 |
| publisher | North Carolina State University |
| record_format | Article |
| series | BioResources |
| spelling | doaj.art-814c245cecee43a2b3fc291e9a3a77c92023-06-26T18:23:49ZengNorth Carolina State UniversityBioResources1930-21262022-11-0117466266637112Characterization of Kraft Lignin Prepared from Mixed Hardwoods by 2D HMQC and 31P NMR AnalysesJi Sun Mun0Justin Alfred Pe III1Sung Phil Mun2Jeonbuk National UniversityJeonbuk National UniversityJeonbuk National UniversityThis study was conducted to determine the lignin substructures, hydroxyl (phenolic + aliphatic) contents, and carboxyl contents in kraft lignin (KL) prepared from mixed hardwoods by using 2D Heteronuclear Multiple Quantum Coherence Nuclear Magnetic Resonance (HMQC NMR) and 31P NMR techniques. Based on 2D HMQC NMR analysis of KL, stilbene and vanillin substructures were present in the aromatic region, while trace amounts of β-O-4 and β-β moieties were detected in the oxygenated aliphatic region. The total hydroxyl content calculated from 31P NMR was 5.24 mmol/g KL. The aliphatic hydroxyl content was 1.04 mmol/g KL, and phenolic hydroxyl content was 4.20 mmol/g KL. Of the phenolic hydroxyl groups, the contribution of syringyl (S) and guaiacyl (G) was 1.02 and 0.97 mmol/g KL, respectively. The S/G molar ratio of KL calculated from 31P NMR was 1.05. The carboxyl content was 0.44 mmol/g KL.https://ojs.cnr.ncsu.edu/index.php/BRJ/article/view/22110kraft ligninmixed hardwoodhmqc31p nmrhydroxyl content |
| spellingShingle | Ji Sun Mun Justin Alfred Pe III Sung Phil Mun Characterization of Kraft Lignin Prepared from Mixed Hardwoods by 2D HMQC and 31P NMR Analyses BioResources kraft lignin mixed hardwood hmqc 31p nmr hydroxyl content |
| title | Characterization of Kraft Lignin Prepared from Mixed Hardwoods by 2D HMQC and 31P NMR Analyses |
| title_full | Characterization of Kraft Lignin Prepared from Mixed Hardwoods by 2D HMQC and 31P NMR Analyses |
| title_fullStr | Characterization of Kraft Lignin Prepared from Mixed Hardwoods by 2D HMQC and 31P NMR Analyses |
| title_full_unstemmed | Characterization of Kraft Lignin Prepared from Mixed Hardwoods by 2D HMQC and 31P NMR Analyses |
| title_short | Characterization of Kraft Lignin Prepared from Mixed Hardwoods by 2D HMQC and 31P NMR Analyses |
| title_sort | characterization of kraft lignin prepared from mixed hardwoods by 2d hmqc and 31p nmr analyses |
| topic | kraft lignin mixed hardwood hmqc 31p nmr hydroxyl content |
| url | https://ojs.cnr.ncsu.edu/index.php/BRJ/article/view/22110 |
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