Table 5.
Quantificational results of the lignin by 2D HSQC spectra (results expressed per 100 aromatic rings)
| Lignocellulosic biomass | Pretreatment severity (CSF) | β-O-4′ | β-5′ | β-β′ | S/G ratio |
|---|---|---|---|---|---|
| Miscanthus × giganteus | Untreated | 42.1 | 9.9 | 3.8 | 1.34 |
| 2.0 | 13.3 | 11.7 | 2.1 | 0.79 | |
| 2.6 | 8.5 | 9.1 | 2.1 | 0.92 | |
| 2.7 | 4.2 | 9.1 | 7.0 | 0.81 | |
| 2.8 | ND | ND | ND | ND | |
| Poplar | Untreated | 43.1 | 11.6 | 6.0 | 1.29 |
| 2.0 | 31.0 | 8.0 | 9.9 | 2.23 | |
| 2.6 | 13.0 | 7.0 | 9.8 | 2.09 | |
| 2.8 | 6.8 | 9.5 | 12.1 | 1.95 | |
| Wheat straw | Untreated | 45.3 | 8.3 | 5.6 | 1.12 |
| 2.0 | 20.3 | 11.3 | 2.1 | 0.84 | |
| 2.6 | 12.4 | 10.6 | 1.9 | 1.04 | |
| 2.7 | 8.1 | 9.8 | 5.0 | 0.96 | |
| 2.8 | 9.3 | 9.2 | 3.9 | 0.95 |
S/G ratio is the ratio S 2,6/G 2
ND contour intensities of the corresponding cross peaks not detected or not allowing an acceptable quantification