TY - JOUR
T1 - Lignin and other aromatic substances released from spruce wood during pressurized hot-water extraction, Part 2: Structural characterization
AU - Sumerskiy, Ivan
AU - Pranovich, Andrey
AU - Holmbom, Bjarne
AU - Willför, Stefan
N1 - 3PK
PY - 2015
Y1 - 2015
N2 - Extraction of ground spruce sapwood with pressurized hot water in an accelerated solvent extractor (ASE) at 170 degrees C during 20, 60, and 100 min resulted in isolation of galactoglucomannans and aromatic substances, including lignin. The isolated lignin preparations were characterized by spectrometric (UV, FT-IR, H-1 NMR, liquid and solid-state C-13 NMR), chromatographic (RP-HPLC, HP-SEC, GC-FID, and GC-MS), conventional pyrolysis, thermally assisted hydrolysis, and methylation techniques in tandem with GC-MS, and classical wet chemistry (methoxyl groups, total and phenolic hydroxyl groups, derivatization followed by reductive cleavage-DFRC). The content of beta-O-4 bonds in isolated lignins was similar to that in MWL and their proportion decreased with extraction time. The oxidation of isolated lignins and content of total hydroxyl groups were significantly increased with extraction time. The lignin structure underwent condensation and demethylation reactions during hot-water extraction. The induction of new phenylcoumaran substructures was proposed in isolated lignins.
AB - Extraction of ground spruce sapwood with pressurized hot water in an accelerated solvent extractor (ASE) at 170 degrees C during 20, 60, and 100 min resulted in isolation of galactoglucomannans and aromatic substances, including lignin. The isolated lignin preparations were characterized by spectrometric (UV, FT-IR, H-1 NMR, liquid and solid-state C-13 NMR), chromatographic (RP-HPLC, HP-SEC, GC-FID, and GC-MS), conventional pyrolysis, thermally assisted hydrolysis, and methylation techniques in tandem with GC-MS, and classical wet chemistry (methoxyl groups, total and phenolic hydroxyl groups, derivatization followed by reductive cleavage-DFRC). The content of beta-O-4 bonds in isolated lignins was similar to that in MWL and their proportion decreased with extraction time. The oxidation of isolated lignins and content of total hydroxyl groups were significantly increased with extraction time. The lignin structure underwent condensation and demethylation reactions during hot-water extraction. The induction of new phenylcoumaran substructures was proposed in isolated lignins.
KW - Functional groups
KW - hot-water extraction
KW - lignin characterization
KW - spruce wood
KW - structural chemical analysis
KW - Functional groups
KW - hot-water extraction
KW - lignin characterization
KW - spruce wood
KW - structural chemical analysis
KW - Functional groups
KW - hot-water extraction
KW - lignin characterization
KW - spruce wood
KW - structural chemical analysis
U2 - 10.1080/02773813.2014.990637
DO - 10.1080/02773813.2014.990637
M3 - Artikel
SN - 0277-3813
VL - 35
SP - 398
EP - 411
JO - Journal of Wood Chemistry and Technology
JF - Journal of Wood Chemistry and Technology
IS - 6
ER -