1064 nm FT-Raman spectroscopy for investigations of plant cell walls and other biomass materials

Abstract

Raman spectroscopy with its various special techniques and methods has been applied to study plant biomass for about 30 years. Such investigations have been performed at both macro- and micro-levels. However, with the availability of the Near Infrared (NIR) (1064 nm) Fourier Transform (FT)-Raman instruments where, in most materials, successful fluorescence suppression can be achieved, the utility of the Raman investigations has increased significantly. Moreover, the development of several new capabilities such as estimation of cellulose-crystallinity, ability to analyze changes in cellulose conformation at the local and molecular level, and examination of water-cellulose interactions have made this technique essential for research in the field of plant science. The FT-Raman method has also been applied to research studies in the arenas of biofuels and nanocelluloses. Moreover, the ability to investigate plant lignins has been further refined with the availability of near-IR Raman. In this paper, we present 1064-nm FT-Raman spectroscopy methodology to investigate various compositional and structural properties of plant material. It is hoped that the described studies will motivate the research community in the plant biomass field to adapt this technique to investigate their specific research needs.

Moisture-related changes in the nanostructure of woods studied with X-ray and neutron scattering

“…These results can be interpreted as a longer axial coherence length of the crystals in the presence of more moisture. Therefore, the changes in both diffraction peaks (200 and 004) imply that the cellulose chains in the CMFs have a higher degree of order in the presence of water than in the absence of it, which is a conclusion previously made based on Raman spectra (Agarwal 2014).…”

Detection and identification of canker and blight on orange trees using a hand‐held Raman spectrometer

“…Vibrational mode Assignment 747 γ(C─O─H) of COOH Pectin [25] 915 ν(C─O─C) in plane, symmetric Cellulose and lignin [26] 1,000 ν 3 (C─CH 3 stretching) and phenylalanine Carotenoids and protein [27,28] 1,155 asym ν(C─C) ring breathing Carbohydrates and cellulose [26] 1,184 ν(C─O─H) next to aromatic ring+σ (CH) Xylan [29,30] 1,218-1,226 δ(C─C─H) Aliphatic [31] and xylan [29] 1,247 C─O stretching (aromatic) Lignin [32] 1,288 δ(C─C─H) Aliphatic [31] 1,326 δCH 2 bending vibration Cellulose and lignin [26] 1,382 δCH 2 bending vibration Aliphatic [31] 1,440 δ (CH 2 ) + δ (CH 3 ) Aliphatic [31] 1,455 δCH 2 bending vibration Aliphatic [31] 1,488 δ (CH 2 ) + δ (CH 3 ) Aliphatic [31] 1,527-1,551 ─C═C─ (in plane) Carotenoids [33,34] 1,601 ν(C─C) aromatic ring+σ (CH) Lignin [35,36] 1,630 C═C─C (ring) Lignin [35][36][37] intensities of all other bands in the spectra collected from leaves of CA and HLB + BL exhibited only very small variations compared with the spectra collected from leaves of HL trees.…”

Synchrotron FTIR and Raman spectroscopy 1 ectroscopy provide unique spectral fingerprints for Arabidopsis floral stem vascular tissues

“…S3A). To test whether these differences were statistically significant, we calculated ratios of spectral peaks areas from already known Raman shift markers, namely, from 2775 to 3125 cm -1 (the composite C-H stretching bands comprising cellulose and hemicelluloses), from 1550 to 1700 cm -1 (lignin Raman shift) and from 1080 to 1140 cm -1 (C-O and C-C bond stretches of cellulose) (Schmidt et al ., 2010; Agarwal, 2014) (Fig. 4).…”