Detailed structural characterization of technical lignins.

	Lignin	P1000	Indulin AT	Alcell	Organosolv-WS	Organosolv-S
	Botanical origin	Wheat straw sarkanda grass	Softwood	Hardwood	Wheat straw	Spruce
	Pulping process	Soda	Kraft	Organosolv	Organosolv	Organosolv
1H–13C HSQC NMR	Subunit composition (molar%)
	H	6.6	2.8	0.0	2.4	0.6
	S	36.0	0.0	57.0	33.6	0.0
	G	48.0	91.5	35.5	60.4	92.9
	G Cα-ox	3.8	5.8	1.3	1.6	6.5
	S Cα-ox	5.6	0.0	6.2	2.0	0.0
	Total Cα-ox	9.4	5.8	7.5	3.6	6.5
	S/G excluding Cα-ox	0.75	0.00	1.61	0.56	0.00
	S/G including Cα-ox	0.80	0.00	1.72	0.58	0.00
	Interunit linkages (per 100 Ar)
	β-O-4 Aryl ether	8.8	7.0	7.8	11.1	0.7
	β-5 Phenylcoumaran	0.9	1.8	1.8	3.7	3.8
	β–β Resinol	0.7	1.2	2.8	0.7	0.8
	β-O-4 α-Oxidized	0.0	0.0	0.0	0.8	0.0
	β-O-4 α-Ethoxylated	0.0	0.0	2.3	0.0	1.9
	E-Enol ether	0.0	2.1	0.0	0.0	0.0
	Z-Enol ether	0.0	0.7	0.0	0.0	0.0
	β-5 Stilbene	1.7	8.1	0.0	0.0	4.0
	β-1 Stilbene	2.5	4.4	1.4	0.0	1.4
	Secoisolariciresinol	0.0	1.8	0.0	0.0	0.0
	Epiresinol	0.7	0.7	1.8	0.0	4.0
	G1–G5/G1–G1	1.7	7.1	1.1	1.9	3.0
	Total	17.0	34.8	19.0	18.2	19.7
	Total native	10.4	10.0	12.5	15.5	5.3
	End-units (per 100 Ar)
	Cinnamyl alcohol	0.7	0.9	0.0	0.0	0.0
	Cinnamaldehyde	0.0	0.0	0.0	0.0	0.6
	Dihydrocinnamyl alcohol	0.4	3.3	0.2	0.0	2.0
	Arylglycerol	0.0	0.8	0.0	0.0	0.0
	Benzaldehyde	0.3	0.0	0.4	0.0	0.1
	Hibbert ketone	0.0	0.0	0.0	2.9	1.1
	Hydroxycinnamic acids (per 100 Ar)
	Ferulate	0	0	0	4.2	0
	p-Coumarate	0	0	0	3.8	0
	Flavonoids (per 100 Ar)
	Tricin	0	0	0	10.3	0
SEC	M w (g mol−1)	2520	3530	2250	2350	2600
	M n (g mol−1)	695	928	933	897	1006
	Đ	3.6	3.5	2.4	2.6	2.6
31P NMR	OH content (mmol g− 1 )
	Aliphatic	1.6	2.1	1.1	2.2	1.4
	Carboxylic acid	1.0	0.4	0.3	0.5	0.1
	Syringyl	0.6	0.0	1.1	0.6	0.0
	Condensed guaiacyl	0.7	1.3	0.8	0.8	1.2
	Guaiacyl	0.7	1.6	0.7	1.1	1.5
	p-Hydroxyphenyl	0.5	0.2	0.2	0.5	0.1
	Total phenolic OH	2.5	3.1	2.8	3.0	2.8