Table 2. ³¹P-NMR analysis of KL, ESL and EIL

Variable	KL	ESL	EIL
Aliphatic OH (mmol/g)	0.38	1.59	0.93
COOH (mmol/g)	0.01	0.04	0.02
C5 condensed (mmol/g)	2.65	2.65	2.02
Guaiacyl OH (mmol/g)	1.16	1.12	0.80
Total OH (mmol/g)	4.20	5.49	3.77

³¹P-NMR: phosphorous-31 nuclear magnetic resonance, KL: kraft lignin, ESL: ethanol-soluble lignin, EIL: ethanol-insoluble lignin.