# Analytical Pyrolysis and Mass Spectrometry to Characterise Lignin in Archaeological Wood
## 3 Results and Discussion
### Single-Shot Py(HMDS)-GC/ms
\begin{table}
\begin{tabular}{c c c c c} \hline \hline \(\mathbf{N}^{\circ}\) & **Compound** & **L. cat.** & \(\mathbf{N}^{\circ}\) & **Compound** & **L. cat.** \\ \hline
25 & 1,3-dihydroxyoxyacetone (2 TMS) & & 83 & unknown lignin II & O \\ \hline
26 & guaiacol (TMS) & SC & 84 & unknown lignin III & O \\ \hline
27 & unknown holocellulose IV & & 85 & vanillic acid (2 TMS) & A \\ \hline
28 & 3-hydroxy-6-methyl-(2H)-pyran-2-one & & 86 & acetosyringone (TMS) & C \\ \hline
29 & unknown holocellulose V & 87 & 5-propyl-3-methoxy-1,2-benzenediol (2 TMS) & D \\ \hline
30 & 2-methyl-3-hydroxy-(4H)-pyran-4-one (TMS) & & 88 & coumaryl alcohol (2 TMS) & D \\ \hline
31 & 2-methyl-3-hydroxymethyl-2- & & & \\ cyclopentenone & 89 & syringe acid methyl ester (TMS) & E \\ \hline
32 & 2,3-dihydrofuran-2,3-diol (2 TMS) & 90 & vanillylpropanol (2 TMS) & LC \\ \hline
33 & 2-furylhydroxymethylketone (TMS) & 91 & \(Z\)-coniferyl alcohol (2 TMS) & M \\ \hline
34 & 5-hydroxymethyl-2-furaldehyde (TMS) & 92 & 4-hydroxy-3,5-dimethoxyoxic acid methyl ester (TMS) & E \\ \hline
35 & 4-methylguaiacol (TMS) & SC & 93 & coniferylaldehyde (TMS) & C \\ \hline
36 & 1,2-dihydroxyobenzene (2 TMS) & 94 & trihydroxycinnamyl alcohol (3 TMS) & D \\ \hline
37 & 2-hydroxymethyl-2,3-dihydropyran-4-one (TMS) & & 95 & syringe acid (2 TMS) & A \\ \hline
38 & 1,4,3,6-dianhydro-\(\alpha\)-\(\alpha\)-D-glucopyranoside (TMS) & & 96 & unknown lignin IV & O \\ \hline
39 & \(Z\)-2,3-dihydroxycyclopent-2-enone (2 TMS) & & 97 & \(E\)-coniferyl alcohol(2 TMS) & M \\ \hline
40 & 4-methylcatechol (2 TMS) & D & 98 & 3,4-dihydroxy-5-methoxybenzoic acid (3 TMS) & A \\ \hline
41 & 4-ethylguaiacol (TMS) & SC & 99 & syringeylpropanol (2 TMS) & LC \\ \hline
42 & syringol (TMS) & SC & 100 & \(Z\)-sinapyl alcohol (2 TMS) & M \\ \hline
43 & 1,4-dihydroxyoxygenase (2 TMS) & & 101 & unknown lignin V & O \\ \hline
44 & arabinofuranose (4 TMS) & & 102 & 3,4-dihydroxyoxinamyl alcohol (3 TMS) & D \\ \hline
45 & 4-vinylguaiacol (TMS) & SC & 103 & trihydroxycinnamyl alcohol I (3 TMS) & D \\ \hline
46 & 3-hydroxy-2-hydroxymethyl-2- & & & \\ cyclopentenone & & 104 & sinapylaldehyde (TMS) & C \\ (2 TMS) & & & \\ \hline
47 & \(E\)-2,3-dihydroxycyclopent-2-enone (2 TMS) & & 105 & trihydroxycinnamyl alcohol II (3 TMS) & D \\ \hline
48 & 4-ethylcatechol (2 TMS) & D & 106 & \(Z\)-2-methoxy-3,4-dihydroxycinnamyl (alcohol (3 TMS)) & D \\ \hline
49 & 3-hydroxy-2-(hydroxymethyl) & & 107 & sinapyl alcohol (TMS) & M \\ \hline
50 & eugenol (TMS) & LC & 108 & \(E\)-sinapyl alcohol (2 TMS) & M \\ \hline
51 & 4-methylsyringol (TMS) & SC & 109 & \(E\)-2-methoxy-3,4-dihydroxycinnamyl (alcohol (3 TMS)) & D \\ \hline
52 & 3-methoxy-1,2-benzenediol (2 TMS) & D & 110 & unknown lignin VI & O \\ \hline
53 & 3,5-dihydroxy-2-methyl-(4H)-pyran-4-one (2 TMS) & & 111 & unknown anhydrorosugar I (dimer) & \\ \hline
54 & 1,6-anhydro-\(\beta\)-D-glucopyranoside (TMS at position 4) & & 112 & unknown anhydrorosugar II (dimer) & \\ \hline \hline \end{tabular}
\end{table} 
Table 3: _Cont._Figure 7: Py(HMDS)-GC/MS chromatographic profiles of (**a**) sound oak wood sample, (**b**) sample 4A from Biskupin [7], (**c**) sample 2212-A from La Marmotta, and (**d**) sample 185-6 from the Oseberg collection [8]. Peak labelling refers to Table 3. In Italics: Lignin pyrolysis products. \begin{table}
\begin{tabular}{c c c c c} \hline \hline \(\mathbf{N}^{\circ}\) & **Compound** & **L. cat.** & \(\mathbf{N}^{\circ}\) & **Compound** & **L. cat.** \\ \hline
55 & 1,6-anhydro-ß-D-glucopyranoside (TMS at position 2) & & 113 & unknown anhydrorosugar III (dimer) \\ \hline
56 & \(Z\)-isoeugenol (TMS) & LC & 114 & unknown anhydrorosugar IV (dimer) \\ \hline
57 & vanillin (TMS) & C & 115 & unknown anhydrorosugar V (dimer) \\ \hline
58 & 1,2,3-trihydroxybenzene (3 TMS) & & 116 & unknown anhydrorosugar VI (dimer) \\ \hline \end{tabular}
\end{table} 
Table 3: _Cont._The parameter usually considered when evaluating the chemical degradation of wood is the holocellulose/lignin (H/L) ratio [15].