Table 2 Lignin compounds in aqueous phase after WEx pretreatment determined by GC-MS: (a) 165 °C, 18 min; (b) 165 °C, 30 min; and (c) 175 °C, 24 min
From: Wet explosion pretreatment of loblolly pine leads to an increase in methoxylation of the lignin
S. no. | Retention time | Compound name | Origin | Peak area | Structure | ||
|---|---|---|---|---|---|---|---|
(min) | (a) | (b) | (c) | ||||
1. | 6.81 | Syringol | S | 8.18E+05 | 1.91E+06 | 1.74E+06 |
|
2. | 7.45 | Vanillin | G | 2.86E+07 | 4.10E+07 | 4.47E+07 |
|
3. | 8.15 | 4-Propyl Guaiacol | G | n/d | 5.55E+05 | 3.56E+06 |
|
4. | 8.50 | Acetovanillone | G | 9.42E+05 | 1.41E+06 | 1.70E+06 |
|
5. | 9.01 | Homovanillyl alcohol | G | n/d | 1.63E+06 | n/d |
|
6. | 9.44 | Isovanillic acid | G | 4.67E+06 | 1.09E+07 | 1.05E+07 |
|
7. | 10.46 | 4-Hydroxy-3-methoxyphenyl glycol | G | 8.34E+05 | 1.86E+06 | n/d |
|
8. | 10.55 | Syringaldehyde | S | 1.66E+07 | 2.42E+07 | 2.00E+07 |
|
9. | 11.34 | Guaiacyl acetone | G | n/d | 3.62E+06 | 8.37E+06 |
|
10. | 11.49 | Coniferyl aldehyde | G | 5.38E+06 | 1.05E+07 | 1.81E+07 |
|
11. | 12.40 | Syringic acid | S | 1.42E+06 | 1.96E+06 | 1.94E+06 |
|
12. | 14.84 | Sinapaldehyde | S | 2.18E+06 | 2.38E+06 | 3.76E+06 |
|
