Abstract
Mild hydrogenolysis has been compared with thioacidolysis as a method for degrading lignins in situ and in isolated form before analysis by gas chromatography/mass spectrometry and quantitative 31P nuclear magnetic resonance (NMR) spectroscopy. Both degradation methods gave similar levels of β-aryl ether-linked phenylpropane units that were released as monomers. Degradation by hydrogenolysis generally gave lower levels of total phenylpropane units when analyzed by 31P NMR, especially in the case of lignins with high levels of condensed units. Overall, these results indicate that mild hydrogenolysis could offer an alternative to thioacidolysis for probing lignin structure.
The authors are grateful to the New Zealand Ministry of Business, Innovation, and Employment for the funding and Diane Steward for assistance with pyrolysis-GC/MS analysis.
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