Table 3.

Comparison of pyrolysis-molecular beam mass spectrometry measured to Raman spectroscopy predicted syringyl/guaiacyl ratios^a.

Plant species	No. of samples	Reference range	pyMBMS S/G average	No. of samples	Prediction range	Raman S/G average	Predicted vs. reference comparisons (p-values)
Acacia microbotrya	5	1.2–1.5	1.3 ± 0.1	10	0.9–1.5	1.3 ± 0.2	0.83
A. saligna	4	1.4–1.9	1.7 ± 0.2	11	1.2–2.0	1.7 ± 0.2	0.69
Corymbia citriodora subsp. citriodora	17	2.1–2.8	2.4 ± 0.2	44	2.0–2.7	2.3 ± 0.1	0.61
Corymbia hybrids	47	1.6–2.8	2.2 ± 0.2	–	–	–	NA
C. torelliana	56	1.8–2.4	2.1 ± 0.1	–	–	–	NA
C. citriodora subsp. variegata	39	2.0–3.2	2.5 ± 0.3	61	2.2–2.7	2.5 ± 0.1	0.65
Eucalyptus argophloia	5	1.9–2.2	2.1 ± 0.1	5	1.7–2.0	1.8 ± 0.1	0.03
E. cladocalyx	3	2.3–2.6	2.5 ± 0.2	2	2.1, 2.4	2.2 ± 0.2	0.40
E. cloeziana	7	1.7–2.3	1.9 ± 0.2	15	1.7–2.4	2.1 ± 0.2	0.31
E. crebra	4	1.4–2.1	1.6 ± 0.4	6	1.2–2.1	1.8 ± 0.3	0.59
E. dunnii	4	2.2–2.8	2.5 ± 0.3	11	2.2–2.5	2.4 ± 0.1	0.36
E. globulus	11	2.3–3.0	2.6 ± 0.2	19	2.0–2.8	2.5 ± 0.2	0.15
E. grandis	2	1.9, 2.2	2.0 ± 0.2	13	1.9–2.4	2.2 ± 0.1	0.23
E. kochii	5	1.9–2.3	2.2 ± 0.2	10	1.7–2.5	2.2 ± 0.2	0.76
E. longirostrata	8	2.1–2.4	2.2 ± 0.1	7	2.0–2.3	2.2 ± 0.1	0.86
E. loxophleba	7	2.1–2.6	2.4 ± 0.1	23	2.2–2.7	2.4 ± 0.1	0.22
E. moluccana	5	2.0–2.5	2.2 ± 0.2	11	1.8–2.5	2.2 ± 0.2	0.91
E. occidentalis	6	2.1–2.5	2.4 ± 0.2	9	2.2–2.6	2.4 ± 0.1	0.55
E. polybractea	8	2.0–2.7	2.3 ± 0.2	12	1.9–2.5	2.2 ± 0.1	0.40

^aData compiled from Lupoi et al. (2014a), “High-throughput prediction of eucalypt lignin syringyl/guaiacyl content using multivariate analysis: a comparison between mid-infrared, near-infrared, and Raman spectroscopies for model development,” Biotechnology for Biofuels, Volume 7, p. 93 and Lupoi et al. (2015), “High-throughput prediction of Acacia and eucalypt lignin syringyl/guaiacyl content using FT-Raman spectroscopy and partial least squares modeling” Bioenergy Research, open access.