Study On The FTIR And GC-MS Fingerprints Identification Of Four Specices Of Redwood Extractives

With the improvement of living conditions, the expectation that returns to nature and green materials is growing. Due to outstanding performance of mechanical strength, visual, audition, touch sensation, and environment friendly, wood and its based products have being attracted increasing attention. Well understanding and identification of wood species becomes a fundamental procedure in the linkage of utilization of wood. Conventionally, wood classification and identification are primarily based on its structural characteristics. Though being of highly accuracy, the traditional identification still has several limitations caused by the operators, especially when detecting those in similar species. The rapid development of wood chemical classification has created numerous techniques, including chromatography, spectroscopy, and immunology. The wood extractives, which are the fourth most compositions except cellulose, hemicellulose, and lignin, contain significant chemical groups. Therefore, the fingerprints of wood extractives are alternatives for wood identification. In the present work, the chemical groups and composition of wood extractives from four species of redwood (namely P.macarocarpus Kurz, D.cochinchinensis Pierre, D.retusa Hesml and D.louvelii R. Viguier) were generated using Fourier Transform Infrared Spectroscopy (FTIR) and Gas Chromatography-Mass Spectrometry (GC-MS), respectively. The wood extractives were extracted by organic solvents, and FTIR and GC/MS fingerprints were obtained based on the statistical analysis. In combination of structural and anatomical characteristic, the potential utilization of such fingerprints in identifying wood species was discussed. The main conclusions are as follows:(1) The correlation coefficient method was used to determine the reproducibility of FTIR and GC-MS spectra obtained by scanning wood extractives from three different batches. The results show that the FTIR and GC-MS spectra are of good consistency and stability. Therefore, the FTIR and GC-MS fingerprints of average values calculated from these three different batches of wood are established.(2) FTIR fingerprints show that the main chemical compositions of extractives from these four species of redwood are phenol, alcohol, ether, fatty acid, lipid, aromatic and hydrocarbon compounds, which confirm that the FTIR spectra is efficient in identifying wood composition. Further analysis of the FTIR fingerprints show that the differences in organic extractives from different species are majorly displayed in three spectra ranges as3700-2800,1500-900, and960-600cm-1, which correspond to atomic absorption of phenols, alcohols, and hydrocarbons, respectively. These compounds are also the main originates which result in different colors and odor. The correlation between FTIR spectra from various wood specices shows that FTIR fingerprints of D.cochinchinensis Pierre, D.retusa Hesml and D.louvelii R. Viguier are highly correlated, approaching correlation parameters more than0.8. The highest correlation exhibited between D.cochinchinensis Pierre and D.louvelii R.Viguier wood. Though the exact chemical compositions are not able to identify, the FTIR spectra is still feasible to detect the major composition of wood extractives, which as consequence is an alternative in wood identification and classification.(3)GC-MS fingerprints show that the main chemical compositions of extractives from these four species of redwood are resin acids, aliphatic alcohols, aldehydes, amines, fatty acids, hydrocarbons, sugar, flavonoids and other aromatic compounds, which confirm that the GC-MS fingerprints are efficient in identification of wood composition. The result shows that D.cochinchinensis Pierre, D.retusa Hesml and D.louvelii R. Viguier are highly correlated. While, the GC-MS fingerprint of wood extractives in P.macarocarpus Kurz are significantly differed from others. The highest correlation displays between D.cochinchinensis Pierre and D.louvelii R. Viguier. The GC-MS fingerprints are capable of providing such information to differ wood extractive from different species. Therefore, it is considered as efficient approach in the identification and classification of wood specie.(4) In comparison with traditional approach, identification and classification of wood specie, based on the chemical fingerprints, are highly efficient. The difficult is largely resulted from chemical composition which is too complicated and complex to be well identified. Even though, the incorporation of traditional approach and chemical fingerprints appears to be more efficient in wood identification and classification, which is believed as one of the useful approaches in the further study.