## 3 Results and Discussion
### Characterization of Main Spectral Regions
#### 3.1.2 Spectral Region 1200-1800 cm\({}^{-1}\)
\begin{table}
\begin{tabular}{c c c c c c} \hline \hline  & & \multicolumn{3}{c}{**Peak (cm\({}^{-1}\))**} \\ \hline
**Cellulose** & _Limum usi-_ & _Abutilon_ & _Cannabis sativa_ & _Corchorus_ & \\
**(Standard)** & _tatitisimum_ & _theophrasti_ & _“Succesiv’ and_ & _olitorius_ & **Assignment and Sources** \\  & & & & & \\  & & & & & \\
897 & 897 & 897 & 898 & 896–897 & and hemicellulose [3; 53; 54; 55; 56]; amorphous & \\  & & & & & & region of cellulose [40]; \\
1059 & 1057 & 1051 & 1052–1060 & 1053–1056 & C–O stretching [10; 53]; \\
1160 & 1157 & 1155 & 1154–1156 & 1155–1157 & C–O–C anti-symmetrical stretching [53]; \\  & & & & & C–O stretching of acetyl group of lignin [3; 8; 36; 43; 54; 56; 57]; stretching of carbonyl group (\(\mathcal{C}\)=O) of lignin [59]; \\
1318 & 1318 & 1320 & 1317–1318 & 1317–1319 & CH\({}_{2}\) rocking [53]; C–O from aromatic ring of polysaccharides [3]; \\  & & & & & C–H bending [3; 53]; C–H deformation vibration in cellulose and hemicillulose [58]; \\  & & & & & CH\({}_{2}\) scissoring vibration [53] from cellulose and hemicillulose [58]; \\
1428 & 1427 & 1423 & 1423–1426 & 1420 & C\({}_{1}\) cellulose and hemicillulose [58]; CH\({}_{2}\) symmetric bending in cellulose [3; 56]; \\
1508 & 1509 & 1508 & 1508 & 1508–1509 & stretching vibration from aromatic ring of lignin [7; 43; 56]; \\ - & 1624 & 1623 & 1625–1628 & 1620–1621 & C=C, lignin [10]; C=O, amide I [53]; \\
1639 & - & - & - & - & O–H bending from adsorbed water [53]; \\  & & & & & C=O stretching [10; 53] from hemicellulose \\  & & & & & [7; 8; 11; 36; 39; 42; 43; 54; 57; 58] \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Summary of peak positions for FT-IR spectra of stems from four fiber species within region 800–1800 cm\({}^{-1}\). (SZTE). For flax and velvet leaf samples, the broad band of this region was situated at a slightly higher wavenumber and the shape of the band was more rounded compared to jute and hemp, which displayed a band with a more acute shape (Figure 5). In the standard sample represented by cellulose paper, there was a band at 1638 cm\({}^{-1}\), which could be attributed to O-H bending vibration from absorbed water [53]. The stems of all four species presented a peak between 1738 and 1740 cm\({}^{-1}\) (Figure 5). Similarly, intense peaks in region 1715-1756 cm\({}^{-1}\) were identified in _Fimbristiylis globulosa_ following FT-IR analysis and were assigned to C=O of ketone and carbonyl groups of hemicellulose [54]. The peak assigned as well to C=O stretching vibration was situated at 1737 cm\({}^{-1}\) for _Abutilion indicum_ fibers [10] and _Chrysanthemum morifolium_[56]. For _Epiremnun aureum_ fibers, the C=O stretching vibration of the acetyl group from hemicellulose produced a peak at a higher wavenumber: 1757 cm\({}^{-1}\)[7]. For bamboo, the peak was found at 1735 cm\({}^{-1}\)[43; 58], as well as for _Thesesia populnea_[39], while for banana fibers the peak was at 1730 cm\({}^{-1}\)[44] (Table 3). An increased proportion of hemicellulose causes this peak to become narrow and sharp and as the plant matures and ages [39]. The decrease in intensity of this peak following treatments was attributed to the cleavage of the molecular bonds [43]. The disappearance of the peak in this region was attributed to the removal of hemicellulose [8; 36; 54]. This peak was not observed in the cellulose standard (Figure 5), since hemicellulose and lignin are mostly removed from the paper during the production process. _Cannabis sativa_ \"Succesiv\" compared to 'Zenit' presented a stronger intensity of bands at 1244-1245 cm\({}^{-1}\) and 1739 cm\({}^{-1}\) (Figure 5), a fact that could indicate a higher lignin and, respectively, higher hemicellulose content in the first cultivar compared to the second one. Out of the analyzed samples, jute samples had the sharpest peak, which would suggest a higher hemicellulose content, while the jute accession from Hungary (SZTE) showed the highest peak intensity out of all samples analyzed. It should be noticed that the peak intensity among jute samples also varied.