ABSTRACTS

Journal

1. Structural analysis of alkaline cooked lignin by pyrolysis-gas chromatography. Evaluation of uniformity in delignification of beech wood chips
   Kami Pa Gikyoushi, 48 (9), 1212-1220 (1994)
2. Structural Analysis of Lignin by Pyrolysis-Gas Chromatography II. Analysis of decayed wood lignin
   Kami Pa Gikyoushi, 49 (4), 735-745 (1995)
3. Structural Analysis of Lignin by Pyrolysis-Gas Chromatography IV. Comparison with nitrobenzene oxidation for determination of decayed hardwoods and kraft-cooked hardwoods
   Kami Pa Gikyoushi, 51(2), 358-366 (1997)
4. Structural Analysis of Lignin by Pyrolysis-Gas Chromatography V. Analysis of lignin in mechanical pulp and paper
   Kami Pa Gikyoushi, 51(6), 932-944 (1997)
5. 5-Hydroxyguaiacyl nuclei as an aromatic constituent of native lignin
   Phytochemistry, 46 (4), 695-700 (1997)
6. Structural characteristics of lignin and wall polysacchaides in steam exploded pulps of oil palm (Elaeis guneensis Jaxq.) frond relating to self-binding mechanism of binderless boards prepared from them.
   Holzforshung, in press.
7. Compositional and structural characteristics of residual biomass from tropical plantations
   Journal of Wood Science, 44 (1), 40-46 (1998)

Symposium

1. Analysis of Lignin in Various Kinds of Paper by Pyrolysis-Gas Chromatography
   The Proceedings of 1995 (62nd) Pulp and Paper Research Conference, Tokyo, June 2, p.86-91 (1995)
2. Analysis of Lignin in Thermomechanical Pulp by Pyrolysis-Gas Chromatography
   International Symposium of Cellulose and Lignocellilosis '96, Guangzho, China, June 6-8, p.177-178 (1996)
3. Preparation of Binderless Boards from Steam Exploded Pulp of Oil Palm Frond and Structural Characteristic of Lignin in Steam Exploded Pulp
   Proceedings of The 41st Lignin Symposium, Nagoya Japan, Oct. 3-4, p.73-76 (1996)
4. 5-Hydroxyguaiacyl Nuclei in Native Lignin
   Proceedings of The 41st Lignin Symposium, Nagoya Japan, Oct. 3-4, p.37-40 (1996)
5. Pyrolysis-Gas Chromatographic Analysis of Ferulic acid Generated in Softwood Thermomechanical Pulps during Light Irradiation
   9^th International Symposium on Wood and Pulping chemistry Poster Presentations, Montréal, Canda, June 9-12, p.110-1-110-4 (1997)
6. Preparation of binderless boards from steam exploded pulp of oil palm frond
   9^th International Symposium on Wood and Pulping chemistry Oral Presentations, Montréal, Canda, June 9-12 p.I1-1-I1-4 (1997)

Structural analysis of alkaline cooked lignin by pyrolysis-gas chromatography

Evaluation of uniformity in delignification of beech wood chips

Satoshi Suzuki, Akiko Izumi, Hiroshi Ohi, Ken-ichi Kuroda and Akira Yamaguchi

* Institute of Agricultural and Forest Engineering, The University of Tsukuba, Tsukuba, Ibaraki 305, Japan

Ten compounds (guaiacol, 4-methylguaiacol, 4-vinylguaiacol, vanillin, trans-isoeugenol, syringol, 4-methylsyringol, 4-vinylsyringol, syringaldehyde and trans-4-propenylsyringol) were identified in pyrolysis products of kraft and soda-THAQ (1,4,4a,9a-tetrahydroanthraquinone) pulps. A high correlation between the ratios of syringyl derivatives to guaiacyl derivatives (S/G) and the amounts of Klason lignin was found. Measuring S/G enabled to estimate the Klason lignin contents of beech pulps. Ununiformity in delignification of beech wood chips after kraft cooking could be evaluated by measuring S/G of slices of the chip. As the delignification during alkaline cooking proceeded, relative yields of guaiacol and syringol to those of the other pyrolysis products from residual lignin in pulps increased.

To clarify the lignin structure which gave guaiacol and syringol in Py-GC, lignin model compounds (syringylglycol- beta -guaiacylether, syringaresinol) were analyzed. Although guaiacol was formed from syringylglycol-beta-guaiacylether, syringol was not formed under the present conditions. On the other hand, syringaresinol gave syringol. These results suggested that the beta -O-4 bond of lignin could be cleaved, and that the C-C bond between Calpha -OH and an aromatic nucleus with a free phenolic hydroxyl group could not be cleaved.

Py-GC was expected to be a promising method for characterization of residual lignin in alkali pulps.

Kami Pa Gikyoushi, 48 (9), 1212-1220 (1994)

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Structural Analysis of Lignin by Pyrolysis-Gas Chromatography II.

Analysis of decayed wood lignin

Satoshi Suzuki, Akiko Izumi, Hiroshi Ohi, Ken-ichi Kuroda and Akira Yamaguchi

When sugi (Cryptomeria japonica) woods is analyzed by Py-GC, the eight main lignin-derived pyrolysis products (guaiacol, 4-methylguaiacol, 4-vinylguaiacol, vanillin, trans-isoeugenol, dihydroconiferyl alcohol, coniferaldehyde and trans-coniferyl alcohol) can be detected. Pyrolysis of woods decayed by Coriolus versicolor and Tyromyces palustris provided the eight pyrolysis products in a smaller yield than that of the sound wood.

In pyrolysis of sugi woods decayed by C. versicolor, the ratios of the peak area of guaiacol to the combined peak areas of the eight pyrolysis products (cpaG) increased with decreasing combined peak areas. On the other hand, in pyrolysis of sugi woods decayed by T. palustris, no clear relationship was found between the ratios of the peak area of pyrolysis products to cpaG and cpaG per sample weight.

Beech (Fagus crenata) woods were also decayed by C. versicolor, Daedalea dickinsii, Ganoderma lucidum and T. palustris, and analyzed by Py-GC. All decayed beech woods showed the smaller ratios of the combined peak areas of the four main syringyl type compounds (syringol, 4-methylsyringol, 4-vinylsyringol, trans-4-propenylsyringol) (sumS) to the combined peak areas of the four main guaiacyl type compounds (guaiacol, 4-methylguaiacol, 4-vinylguaiacol, trans-isoeugenol) (sumG) than that of sound wood. This suggests that syringyl units of lignin were preferentially degraded to guaiacyl units. The ratios of the peak area of guaiacol to sumG and the ratios of the peak area of syringol to sumS increased in pyrolysis of beech woods decayed by the above four fungi.

To clarify the convincing pyrolytic origins of the lignin structures giving syringol and guaiacol in high yields, some lignin dimer model compounds were subjected to Py-GC: syringylglycol- beta -guaiacyl ether (SG-OH), dehydrodiisoeugenol (DDI) and alpha -guaiacoxyacetosyringone (SG=O). A phenylcoumaran type lignin model compound, DDI, did not give guaiacol. Similarly syringol was not formed from SG-OH, which is the beta -O-4 analogue having a hydroxyl group at the C alpa -position. On the other hand, the beta -O-4 analogue having a carbonyl group at the C alpha -position, SG=O, gave syringol by the pyrolytic cleavage of the bond between the C atom and aromatic ring in a 3mol% yield. These findings suggest that the formation of alpha -carbonyl groups in the lignin macromolecule by fungal treatments should be one of the reasons why the ratios of guaiacol and syringol increased in Py-GC of the decayed woods. Py-GC is expected to be a promising method for characterization of the decayed wood lignin.

Kami Pa Gikyoushi, 49 (4), 735-745 (1995)

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Structural Analysis of Lignin by Pyrolysis-Gas Chromatography IV. Comparison with nitrobenzene oxidation for determination of decayed hardwoods and kraft-cooked hardwoods

Junji Tanaka, Akiko Izumi, Satoshi Suzuki, Hiroshi Ohi and Ken-ichi Kuroda

* Institute of Agricultural and Forest Engineering, The University of Tsukuba, Tsukuba, Ibaraki 305, Japan

European beech (Fagus silvatica) woods were decayed by a brown-rot fungus (Tyromyces palustris) or a white-rot fungus (Coriolus versicolor), and beech (Fagus crenata) woods were cooked with kraft liquor. Residual lignin contents of wood samples were measured by the Klason lignin methods. Lignin was analyzed by Py-GC and the alkaline nitrobenzene oxidation method quantitatively without isolation from woods. The yields of the pyrolysis products were obtained on the basis of the residual lignin in decayed woods, and changes in the yields and their relative compositions during the decay for 180 days were investigated. The molar ratios of syringyl type pyrolysis products to guaiacyl ones (S/G ratios) measured by Py-GC were compared with the molar ratios of syringaldehyde to vanillin (S/V ratios) obtained by the nitrobenzene oxidation.

(1) In pyrolysis of 180 days-decayed woods by Tyromyces palustris, the yields of trans-coniferyl alcohol and trans-sinapyl alcohol sharply decreased.
(2) In those by Coriolus versicolor, the yields of trans-coniferyl alcohol and trans-sinapyl alcohol decreased, and relative compositions of guaiacol and syringol clearly increased.
(3) For decayed woods by Coriolus versicolor, the yields of syringyl type pyrolysis products decreased more rapidly than those of guaiacyl ones with increase of decaying days. The S/G ratios measured by Py-GC were in good agreement with the S/V ratios obtained by the nitrobenzene oxidation.
(4) In pyrolysis of kraft-cooked woods, the yields of trans-coniferyl alcohol and trans-sinapyl alcohol decreased, and relative compositions of guaiacol and syringol increased.
(5) The S/G ratios of residual lignin in kraft-cooked woods decreased with increase of cooking time, and those were in good agreement with the S/V ratios.

Kami Pa Gikyoushi, 51 (2), 358-366 (1997)

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Structural Analysis of Lignin by Pyrolysis-Gas Chromatography V. Analysis of lignin in mechanical pulp and paper

Satoshi Suzuki, Hiroshi Ohi, Ken-ichi Kuroda

* Institute of Agricultural and Forest Engineering, The University of Tsukuba, Tsukuba, Ibaraki 305, Japan

Six species: akamatsu (Pinus densiflora), ezomatsu (Picea jezoensis), karamatsu (Larix kaempferi), spruce (Picea sp.), Douglas-fir (Pseudotsuga menziesii), todomatsu (Abies sachalinensis), which were used as raw materials of mechanical pulps, were analyzed by Py-GC. The eight main lignin-derived pyrolysis products (guaiacol, 4-methylguaiacol, 4-vinylguaiacol, vanillin, trans-isoeugenol, dihydroconiferyl alcohol, coniferaldehyde and trans-coniferyl alcohol) were detected. Comparing the pyrolysis products of woods, different yields of trans-coniferyl alcohol between the species were observed. Spruce and Douglas-fir showed high yields of trans-coniferyl alcohol, whereas akamatsu and todomatsu did low yields.

At a laboratory, thermomechanical pulp were made from Akamatsu and ezomatsu wood, and analyzed by Py-GC. The yields of the main pyrolysis products were not changed by thermomechanical pulping. The pyrogram patterns of lignin in wood materials were kept after thermomechanical pulping.

Py-GC was applied to the characterization of lignin in seventeen kinds of papers: printing and writing papers (wood containing paper, woodfree paper, and wood containing coated paper). Some pyrolysis products from lignin were detected in the analysis of several papers including mechanical pulp. Their characteristics of pyrogram suggested those of the mechanical pulp. Py-GC is more useful than other methods such as alkaline nitrobenzene oxidation because it provides more information on degradation products than alkaline nitrobenzene oxidation. Py-GC was found to be unaffected by filler in paper, while filler usually interfered with exact measurement of the Klason lignin. A kind of paper including hardwood mechanical pulp was clearly distinguished from the others by the detection of syringyl type pyrolysis products. It was considered that the higher yields of the pyrolysis products by Py-GC and the aldehydes by alkaline nitrobenzene oxidation showed the presence of mechanical pulps in papers in higher ratio. When a pyrogram of mechanical pulp is known, it seems to be able to distinguish the paper including the pulp from the others.

Kami Pa Gikyoushi, 51 (6), 932-944 (1997)

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5-Hydroxyguaiacyl nuclei as aromatic constituent of native lignin.

Satoshi Suzuki*, Thi Bach Tuyet Lam** and Kenji Iiyama*

* Asian Natural Environmental Science Centre. The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113, Japan;

**School of Biochemistry, La Trobe University Bundoora Victoria 3083 Australia

Phytochemistry, 46 (4), 695-700 (1997)

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Structural characteristics of lignin and wall polysacchaides in steam exploded pulps of oil palm (Elaeis guneensis Jaxq.) frond relating to self-binding mechanism of binderless boards prepared from them

Satoshi Suzuki, Hiroyuki Shintani, Seung-Young Park, Keiko Saito, Nikhom Laemsak, Motoaki Okuma and Kenji Iiyama

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Compositional and structural characteristics of residual biomass from tropical plantations

Satoshi Suzuki, Evelyn B. Rodriguez, Kyoko Saito, Hiroyuki Shintani, Kenji Iiyama

Journal of Wood Science, 44 (1), 40-46 (1998)

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Analysis of Lignin in Various Kinds of Paper by Pyrolysis-Gas Chromatography

Satoshi Suzuki, Hiroshi Ohi, Ken-ichi Kuroda and Akira Yamaguchi

The Proceedings of 1995 (62nd) Pulp and Paper Research Conference, Tokyo, June 2, p.86-91 (1995)

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Analysis of Lignin in Thermomechanical Pulp by Pyrolysis-Gas Chromatography

Satoshi Suzuki, Hiroshi Ohi, Ken-ichi Kuroda

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Preparation of Binderless Boards from Steam Exploded Pulp of Oil Palm Frond and Structural Characteristic of Lignin in Steam Exploded Pulp

Satoshi Suzuki^*1, Hiroyuki Shintani*1 , Seung-Young Park *1, Nikhom Laemsak*1, Motoaki Okuma*1 , Kenji Iiyama*2

*1 Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo, 113 Japan. *2 Asian Natural Environmental Science Center, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo, 113 Japan.

Bjorkman lignin from oil palm frond, and this lignin was characterized by the presence of significant amount of esterified p-hydroxybenzoic acid. Most ester bonds and b-O-4 bonds were cleaved during steam explosion process, and the other hand, guaiacyl units were condensed greatly, as revealed by ¹H and ¹³C-NMR spectra. Moreover, the structural difference of the aromatic units between 2.5MPa and 3.0MPa exploded pulp, were observed in 1H, 13C-NMR and FTIR spectra. The ratios of syringyl derivatives to guaiacyl derivatives (S/G) from total ion pyrograms were decreased by hot pressing.

As a result of the analytical pyrolysis, 5-hydroxymethylfurfural, derived from cellulose, was increased by the steam explosion especially 3.0MPa. Significant amount of furfural, derived from pentosan, was detected in the pulp steam exploded under the condition of 2.5MPa, and furfural was increased during hot pressing. These facts suggest that furfural is involved in the formation of binder together with lignin.

Proceedings of The 41st Lignin Symposium, Nagoya Japan, Oct. 3-4, p.73-76 (1996)

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5-Hydroxyguaiacyl Nuclei in Native Lignin

Kenji Iiyama*1, Satoshi Suzuki*2, Thi Bach Tuyet Lam*3

*1Asian Natural Environmental Science Center, The University of Tokyo, 1-1-1, Yayoi, Bunkyo-ku, Tokyo, 113 Japan. *2Graduate School of Agriculture and Life Science, The University of Tokyo, 1-1-1, Yayoi, Bunkyo-ku, Tokyo, 113 Japan. *3School of Biochemistry, La Trobe University, Bundoora, Vic., 3083 Australia.

Proceedings of The 41st Lignin Symposium, Nagoya Japan, Oct. 3-4, p.37-40 (1996)

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Pyrolysis-Gas Chromatographic Analysis of Ferulic acid Generated in Softwood Thermomechanical Pulps during Light Irradiation

Satoshi Suzuki^*1,3, Hiroshi Ohi^*2

*1 Asian Natural Environmental Science Center, The University of Tokyo, 1-1-1 
Yayoi, Bunkyo-ku, Tokyo 113, Japan

*2 Institute of Agricultural and Forest Engineering, The University of Tsukuba, 
Tsukuba, Ibaraki 305, Japan

*3: Present Address: Toyama Forestry and Forest Products Research Center, 
4940 Kurokawashin Kosugi-machi Imizu Toyama 939-03, Japan

There were no significant differences in yields of pyrolysis products from lignin between thermomechanical pulps and original wood meal, suggesting that the structural feature of lignin in wood materials has not been changed during thermomechanical pulping. Terminal groups of coniferyl alcohol types in lignin could be degraded after light irradiation of TMP sheets. Ferulic acids in TMP, TMP irradiated and original woods were analyzed by on-line methylation Py-GC using tetramethylammonium hydroxide. No ferulic acid were detected at all in those samples. These results suggest that formation of ferulic acid would not contribute to the yellowing of TMP.

9^th International Symposium on Wood and Pulping chemistry Poster Presentations, Montréal, Canda, June 9-12, p.110-1-110-4 (1997)

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Preparation of Binderless Boards from Steam Exploded Pulp of Oil Palm Frond

Satoshi Suzuki, Hiroyuki Shintani, Nikhom Laemsak, Kyoko Saito, Motoaki Ohkuma and Kenji Iiyama

9^th International Symposium on Wood and Pulping chemistry Oral Presentations, Montréal, Canda, June 9-12 p.I1-1-I1-4 (1997)

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