Determination of Eucalyptus spp lignin S/G ratio: a comparison between methods.
The syringyl/guaiacyl ratio was determined for six different Eucalyptus spp. wood clones cultivated in four regions in Brazil. The determinants were made by pyrolysis-gas chromatography-mass spectrometry (Py-GC-MS) and the results were compared with those obtained by alkaline nitrobenzene oxidation method. The S/G ratios were obtained considering all the identified lignin derivatives in the pyrograms and also using two groups of markers. The first group of markers consisted of guaiacol, 4-methylguaiacol, 4-vinylguaiacol, trans-isoeugenol, syringol, 4-methylsyringol, 4-vinylsyringol and trans-4-propenylsyringol compounds as markers. The second group included guaiacol, 4-methylguaiacol, 4-vinylguaiacol, vanillin, 4-ethylsyringol, 4-vinylsyringol, syringaldehyde, syringylacetone and trans-4-propenylsyringol. It was observed from the statistical analysis that the values of S/G obtained by Py-GC-MS using the two groups of markers did not differ significantly from those obtained by nitrobenzene oxidation method.
Department of Chemistry, Federal University of Viçosa, 36570-000 Viçosa, MG, Brazil.
Cleiton A
CA
Nunes
Cláudio F
CF
Lima
Luiz C A
LC
Barbosa
Jorge L
JL
Colodette
A F G
AF
Gouveia
Flaviano O
FO
Silvério
D002851:Chromatography, High Pressure Liquid; D005052:Eucalyptus / Q000737:chemistry*; D008401:Gas Chromatography-Mass Spectrometry; D008031:Lignin / Q000032:analysis*; D010084:Oxidation-Reduction
D008031:Lignin