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Table 4 Summary of techniques discussed for the assessment of the relative amounts of wood components

From: A review of analytical methods for assessing preservation in waterlogged archaeological wood and their application in practice

Technique Information yielded Advantage Disadvantage Sample requirements
Gravimetric analysis (Acid insoluble lignin/TAPPI methods) Relative composition by mass of extractives, carbohydrates and lignin in wood; ash content by combustion usually carried out alongside Numerical values allow comparison; well-established technique; cheap; more detail than loss of wood substance Time consuming; large degree of error; potentially dangerous chemicals; too harsh for heavily degraded samples Dry sample (not conserved); destructive; > 1 g recommended (larger amount reduces error)
Combustion analysis (CHN(S)) Relative composition by mass of CHN (and S in some cases) Straightforward data interpretation; readily available No structural information; oxygen content not directly analysed; determination of relative amounts only; heavily influenced by conservation agents and wood species Dry or conserved* sample; destructive; approx. 2 mg sample required
Thermogravimetry Relative composition by mass of water, cellulose, lignin and ash Small sample size; relatively fast (compared to extraction) Less familiar than many techniques; requires specialist equipment; lignin content can be very difficult to determine in archaeological samples Dry or conserved* sample; destructive; approx. 5 mg sample required
Specialist instrumentation (FTIR, Raman, Py-GC, NMR) Relative composition of celluloses and lignin (L:C ratios) Simultaneous analysis of molecular changes; small sample sizes; fast analysis (compared to gravimetry) Requires specialist instrumentation; cannot accurately assess ash and water content See individual entries in Table 6
  1. * Denotes that although conserved samples can be analysed, the conservation history of the object must be known to allow correction of the data