Determination of Eucalyptus spp lignin S/G ratio: a comparison between methods

Area of Science:

• Wood Chemistry
• Analytical Chemistry
• Biomass Characterization

Background:

• The syringyl/guaiacyl (S/G) ratio is a key indicator of lignin composition in hardwoods.
• Accurate determination of S/G ratio is crucial for biomass utilization in biorefineries.
• Eucalyptus species are important sources of hardwood biomass.

Purpose of the Study:

• To determine the S/G ratio for six Eucalyptus spp. wood clones from Brazil.
• To compare S/G ratio results obtained by pyrolysis-gas chromatography-mass spectrometry (Py-GC-MS) with the alkaline nitrobenzene oxidation method.

Main Methods:

• Lignin derivatives were analyzed using pyrolysis-gas chromatography-mass spectrometry (Py-GC-MS).
• Two distinct groups of lignin-derived markers were employed for quantification.
• Results were statistically compared against those from the alkaline nitrobenzene oxidation method.

Main Results:

• Py-GC-MS analysis provided S/G ratios for the studied Eucalyptus wood clones.
• No significant statistical differences were observed between S/G ratios determined by Py-GC-MS (using both marker groups) and the nitrobenzene oxidation method.

Conclusions:

• Py-GC-MS is a valid and reliable method for determining the S/G ratio in Eucalyptus wood.
• The chosen marker groups in Py-GC-MS accurately reflect lignin composition compared to established methods.
• This finding supports the use of Py-GC-MS for efficient biomass characterization in Eucalyptus.