Delignification of maize stems by peroxymonosulfuric acid, peroxyformic acid, peracetic acid, and hydrogen peroxide. 1. Physicochemical and structural characterization of the solubilized lignins.
Water-treated maize stems were subjected to delignification with peroxymonosulfuric acid at 20 degrees C for 144 h, with peroxyformic acid at 80 degrees C for 6 h, with peracetic acid at 50 degrees C for 6 h, and with 2% hydrogen peroxide at 45 degrees C for 12 h at pH 1.5, 4.4, 9.5, 11.5, 12.0, and 12.6, respectively, which solubilized 47.1, 91.3, 33.3, 16.6, 15.9, 17.4, 86.2, 87.7, and 91. 3% of the original lignin, respectively. Substantial lignins were released during the treatment with peroxyformic acid and hydrogen peroxide at pH > or =11.5, whereas an insignificant effect on delignification was observed by using peroxymonosulfuric acid, peracetic acid, and hydrogen peroxide under acidic, natural, and weakly alkaline media conditions. The structures of the isolated lignin preparations were investigated by chemical analysis, gel permeation chromatography, and UV, FT-IR, and (13)C NMR spectroscopy.
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The BioComposites Centre, University of Wales, Bangor, Gwynedd LL57 2UW, United Kingdom.
Tomkinson
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Zhu
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Wang
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SQ
D005561:Formates; D006861:Hydrogen Peroxide; D007202:Indicators and Reagents; D008031:Lignin / Q000737:chemistry* / Q000302:isolation & purification; D010463:Peracetic Acid; D018547:Plant Stems / Q000737:chemistry; D017550:Spectroscopy, Fourier Transform Infrared; D013464:Sulfuric Acids; D003313:Zea mays / Q000737:chemistry*
D005561:Formates; D007202:Indicators and Reagents; D013464:Sulfuric Acids; C008817:peroxyformic acid; D008031:Lignin; D006861:Hydrogen Peroxide; D010463:Peracetic Acid