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Titolo:
FOURIER-TRANSFORM RAMAN ASSIGNMENT OF GUAIACYL AND SYRINGYL MARKER BANDS FOR LIGNIN DETERMINATION
Autore:
TAKAYAMA M; JOHJIMA T; YAMANAKA T; WARIISHI H; TANAKA H;
Indirizzi:
KYUSHU UNIV,DEPT FOREST PROD FUKUOKA 81281 JAPAN KYUSHU UNIV,DEPT FOREST PROD FUKUOKA 81281 JAPAN
Titolo Testata:
SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY
fascicolo: 10, volume: 53, anno: 1997,
pagine: 1621 - 1628
SICI:
1386-1425(1997)53:10<1621:FRAOGA>2.0.ZU;2-Y
Fonte:
ISI
Lingua:
ENG
Soggetto:
CELL-WALLS; SPECTROSCOPY; MICROPROBE; WOOD;
Keywords:
FT RAMAN; GUAIACYL LIGNIN; SYRINGYL LIGNIN; MARKER BAND; NONDESTRUCTIVE ANALYSIS;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Science Citation Index Expanded
Citazioni:
23
Recensione:
Indirizzi per estratti:
Citazione:
M. Takayama et al., "FOURIER-TRANSFORM RAMAN ASSIGNMENT OF GUAIACYL AND SYRINGYL MARKER BANDS FOR LIGNIN DETERMINATION", SPECT ACT A, 53(10), 1997, pp. 1621-1628

Abstract

A near infrared fourier transform Raman (NIR-FTR) spectroscopic technique was utilized to characterize lignin in wood. The Raman bands for C=C stretching derived from 4-hydroxy-3-methoxyphenyl (guaiacyl) nuclei and from 3,5-dimethoxy-4-hydroxyphenyl (syringyl) nuclei exist independently. The NIR-FTR analysis of a series of lignin model compounds indicated that a syringyl band was shifted to a lower frequency compared to a guaiacyl band. This shift was also observed in chemically synthesized lignin (DHP). Syringyl DHP, in which all the aromatic nuclei consist of syringyl type, exhibited a C=C stretching band at 1594 cm(-1), while guaiacyl DHP exhibited the band at 1599 cm(-1). These bands were designated as syringyl and guaiacyl marker bands, respectively. Chemical and physical treatment of hardwood and softwood exhibited different characteristics. One of the reasons is the chemical structure oi lignin. Softwood mainly contains only guaiacyl lignin, while hardwood contains both guaiacyl and syringyl lignin, and the syringyl/guaiacyl (S/G) ratio varies among species. Under high-resolution conditions (1 cm(-1)), the NIR-FTR spectra of 10 hardwoods (wood meal samples) revealed that both syringyl and guaiacyl marker bands existed. On the other hand, the spectra of softwoods contained only a guaiacyl marker bands existed. On the other hand, the spectra of softwoods contained only a guaiacyl marker band. The S/G ratio in hardwood calculated from the peak area intensity ratio of two marker bands shows a linear relationship with the SIG ratio obtained from conventional nitrobenzene oxidationanalysis with the correlation factor>0.96. Furthermore, if peak component separation analysis was combined, low-resolution spectral data gave a similar S/G ratio. Either syringyl of guaiacyl marker bands can be assigned in the NIR-FTR spectra of wood blocks (saw-cut surface). This spectral technique may provide an easy-handling and non-destructiveanalytical method for lignin determination. (C) 1997 Elsevier ScienceB.V.

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Documento generato il 25/11/20 alle ore 14:34:12