Table 3 Semi-quantitative information of lignin samples
Lignin substructure | δC/δH (ppm) | L 1 | L 2 | L 3 | H 1 | H 2 | H 3 |
|---|---|---|---|---|---|---|---|
%a | %a | %a | %a | %a | %a | ||
S | 103.1/6.60 | 32.4 ± 1.8 | 49.1 ± 0.3 | 48.2 ± 0.8 | 41.1 ± 0.7 | 38.5 ± 0.2 | 34.8 ± 0.3 |
S’ | 106.0/7.23 | 7.1 ± 0.1 | 7.7 ± 0.0 | 7.1 ± 0.6 | 8.5 ± 0.2 | 5.7 ± 0.4 | 5.5 ± 0.0 |
S condensed | 105.4/6.42 | 45.3 ± 1.2 | 26.8 ± 0.0 | 29.0 ± 0.0 | 38.5 ± 0.5 | 39.8 ± 0.1 | 40.7 ± 0.1 |
Total S | – | 84.6 ± 0.3 | 83.6 ± 0.3 | 84.3 ± 0.2 | 88.1 ± 0.0 | 83.9 ± 0.4 | 81.0 ± 0.1 |
G | 110.2/6.91 | 8.1 ± 0.1 | 14.5 ± 0.0 | 13.5 ± 0.4 | 9.5 ± 0.0 | 14.5 ± 0.3 | 16.6 ± 0.0 |
G condensed | 112.0/6.65 | 7.3 ± 0.6 | 2.5 ± 0.4 | 2.1 ± 0.2 | 2.4 ± 0.0 | 1.6 ± 0.0 | 2.4 ± 0.0 |
Total G | – | 15.4 ± 0.4 | 17.0 ± 0.4 | 15.7 ± 0.2 | 11.2 ± 0.0 | 16.1 ± 0.4 | 19.0 ± 0.1 |
PB | 130.9/7.63 | 7.5 ± 0.0 | 7.9 ± 0.2 | 9.5 ± 0.3 | 4.2 ± 0.2 | 6.0 ± 0.7 | 6.1 ± 0.4 |
S/G | – | 5.5 ± 0.1 | 4.9 ± 0.1 | 5.4 ± 0.1 | 7.4 ± 0.0 | 5.2 ± 0.1 | 4.3 ± 0.0 |
β-O-4 | 71.6/4.85 | 66.5 ± 0.0 | 71.2 ± 0.7 | 76.2 ± 2.7 | 59.5 ± 1.0 | 70.8 ± 2.0 | 74.9 ± 1.0 |
β-5 | 87.0/5.43 | 11.7 ± 0.0 | 10.7 ± 0.6 | 6.7 ± 0.8 | 17.1 ± 1.5 | 9.5 ± 0.7 | 7.8 ± 0.8 |
β–β | 85.0/4.63 | 21.8 ± 0.0 | 18.1 ± 1.3 | 17.2 ± 1.8 | 23.4 ± 0.4 | 19.8 ± 0.3 | 17.3 ± 0.2 |